Quintessenz Verlag Berlin @ zahnigroups

2010 Guidelines of the Academy of Osseointegration for the Provision of Dental Implants and Associated Patient Care

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:03:05 +0200

Retrospective Study of the Long-Term Survival of 980 Implants Placed in a Periodontal Practice

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:03:03 +0200

Purpose: To assess the long-term behavior of 980 implants placed in a private practice and evaluate the influence of periodontitis history and smoking habit on implant survival rates.
Materials and Methods: A retrospective review of clinical records of consecutively treated patients with Astra Tech implants was conducted. This review included all patients treated between February 1994 and January 2005. Clinical histories were reviewed, and data were gathered on clinical and radiographic examinations. A record was kept on smoking habits, periodontitis history, length and diameter of implant(s), and whether the sinus was elevated. Cumulative survival proportions analysis was performed, and Cox regression multivariate analysis modified for correlated dependent observations was also used, with the implant as the unit of analysis.
Results: A total of 323 patients (185 [57.3%] female; mean age, 55.4 ± 15.2 years) received 980 implants. Of the implants evaluated in this study, 71.1% were placed in patients who were undergoing periodontal maintenance care and 38.8% were placed in smokers. The cumulative survival rate was 96.2% at 5 years; 4.3% of implants failed; 57.1% of failures occurred before implant loading. Tobacco use and periodontitis did not affect the risk of failure, and their interaction did not show significance (P = .386). Implants from individuals with many implants and those placed in patients with sinus elevation showed a higher risk of failure (P < .05). Regression analysis showed no significant interaction between periodontitis history, tobacco use, and implant failure.
Conclusions: Implant placement is an effective and reliable long-term treatment, even in periodontal patients under maintenance care and with a smoking habit. Combined analysis of tobacco use and history of periodontitis showed no significant interaction with implant failure in this sample.

Five-Year Follow-up of Wide-Diameter Implants Placed in Fresh Molar Extraction Sockets in the Mandible: Immediate Versus Delayed Loading

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:03:02 +0200

Purpose: The aim of this study was to compare the long-term success rates of wide-diameter implants in the mandibular molar region placed immediately after extraction and loaded either immediately or after a 3-month healing period. Materials and Methods: In 71 patients, 120 implants were positioned immediately after tooth extraction; 60 implants (immediate loading group) were loaded immediately and 60 were loaded after 3 months (delayed loading group). Radiographic examinations were made at baseline and at 1, 2, 3, 4, and 5 years after implant placement. Results: After 5 years, a survival rate of 96.67% was reported for all implants (failure rate, 3.33%). Four implants were lost, two from the immediate loading group and two from the delayed loading group. There were no patient dropouts in either group. Conclusions: Wide-diameter implants placed in fresh extraction sockets and loaded immediately or after a delay showed no significant clinical or radiographic differences after 5 years.

One-Step Approach for Implant Placement and Subantral Bone Regeneration Using Bovine Hydroxyapatite: A 2- to 6-Year Follow-up Study

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:03:01 +0200

Purpose: Pneumatized sinuses in the posterior maxilla often make implant placement difficult or impossible. A sinus lifting procedure can reliably augment the bone height, with the highest success rates reported when two-stage implants are placed 6 to 9 months later. The aim of this study was to evaluate the clinical reliability of a shortened approach in which nonsubmerged implants were placed at the time of sinus augmentation.
Materials and Methods: All patients treated with sinus floor elevation and simultaneous implant placement at the authors’ institution from 1999 to 2004 were retrospectively selected for a long-term follow-up study. Sinus elevation was considered when the remaining subantral bone height did not reach 6 mm in one or more implant sites. The lateral window technique was performed using bovine hydroxyapatite as a filler, and nonsubmerged implants were placed immediately. Implant and prosthodontic survival rates, as well as biologic and prosthodontic complications, were evaluated 2 to 6 years after loading.
Results: In a sample of 40 patients, 50 subantral bone augmentations were performed and 102 implants were placed using the one-stage approach. One implant remained submerged because of a lack of primary stability. No sinusitis was noted. Only two implants were lost before loading. No implants failed after the definitive restorations were placed, leading to a 98% implant survival rate and 100% prosthodontic survival rate after 2 to 6 years.
Conclusions: Subantral bone regeneration with bovine hydroxyapatite as a space filler is an effective and safe procedure allowing high survival rates of implants placed in the posterior maxilla. If the remaining bone is sufficient to ensure primary stability, implant placement can be performed simultaneously with sinus lifting, and even in a nonsubmerged fashion.

Removable Implant-Prosthodontic Rehabilitation of the Edentulous Mandible: Five-Year Results of Different Prosthetic Anchorage Concepts

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:03:00 +0200

Purpose: The present study evaluated implant and peri-implant outcomes as well as prosthodontic maintenance efforts for implant/bar-supported mandibular prostheses with different prosthesis anchorage systems.
Materials and Methods: Seventy-six patients who received two or four interforaminal implants were assigned to one of three different bar designs and subsequently to different prosthesis supporting systems. Forty-nine patients received implants and a mucosa-supported implant-retained overdenture (OD) with an ovoid bar (two implants; design 1) or multiple ovoid bars (four implants; design 2). Twenty-seven patients received four implants and a rigid implant-supported prosthesis (ISP) with a milled bar (design 3). Implant survival, peri-implant parameters (marginal bone resorption, pocket depth, and plaque, bleeding, gingival, and calculus indices), and postinsertion prosthodontic maintenance were followed over a 5-year period and compared among the different retention modalities. At the most recent follow-up examination, subjective patient satisfaction was additionally evaluated using a simplified scoring system (ranging from 1 = not satisfactory to 5 = excellent).
Results: Implant survival rates (100%) and all peri-implant parameters evaluated showed no differences among the three designs used for implant prosthesis anchorage. Prosthodontic maintenance did not differ between the different ODs (OD design 1: average of 1.04 maintenance visits/year/patient; OD design 2: 1.2 maintenance visits/year/patient), but it was significantly lower for the dentures that were rigidly stabilized with milled bars (ISP: 0.37 maintenance visits/year/patient). A high subjective satisfaction rate (range: 4.5 to 5.0) was registered at the final examination, without any differences among the designs used.
Conclusions: Rigid anchorage with milled bars on four-implant prostheses combined with a metal-reinforced framework showed a lower extent of prosthodontic maintenance issues than round bars on two- or four-implant overdentures with resilient denture stabilization. Nevertheless, implants and peri-implant structures were not negatively affected by either resilient or rigid anchorage mechanisms.

Applications of Surgical Navigational Systems for Craniofacial Bone-Anchored Implant Placement

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:58 +0200

The following case reports describe the use of computer-assisted image-guided surgery to plan and place craniofacial bone-anchored implants (CBAI) for facial prosthetic reconstructions. During virtual planning, the soft tissue and bone visualizations are segmented from spiral computed tomography data and the patient’s normal anatomy is mirrored onto the skull of the defect side, thus providing the ability to visualize the future prosthetic form. CBAI are planned in the anatomical area that leads to the best cosmetic results. Bone quantity is directly assessed at the surgical sites with the integrated instrumentation while the clinician navigates within the images and virtual planning scheme in real time. The aim of this report is to show a technique that incorporates computer-assisted image-guided surgery into the preoperative planning and surgical placement of CBAI. The use of this technology to plan and place implants in the most ideal location for facial prosthetic treatment eliminated the need for a conventional or prototyped surgical guide.

Peri-Implant Bone Level Around Implants with Platform-Switched Abutments

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:57 +0200

Purpose: The purpose of this clinical trial was to evaluate whether the crestal bone height around dental implants could be influenced by the use of a platform-switching protocol.
Materials and Methods: All implants placed in the year 2006 in healed bone without any need for ridge augmentation were included in this study. The following groups were created: (1) wide-diameter implants were placed subcrestally and regular-diameter cover screws were connected; (2) regular-diameter implants were placed at the crest and regular-diameter cover screws were connected. Standardized radiographs were obtained after insertion of the definitive prosthesis and after 1 year. Calibrated measurements were conducted initiating from the mesial and distal bone peaks to the implant-abutment junction. The average value of the mean medial and mean distal values was calculated and analyzed with an unpaired two-tailed t test. P values < .05 were regarded as statistically significant.
Results: In all, 89 dental implants in 36 patients were evaluated. The implants with a platform-switched configuration (n = 75) exhibited statistically significantly less bone loss at time of insertion of the definitive prosthesis (0.30 ± 0.07 mm versus 0.68 ± 0.17 mm; P < .05) and at 1 year (0.39 ± 0.07 mm versus 1.00 ± 0.22 mm, P < .01) when compared to the nonplatform-switched implants (n = 14).
Conclusion: Platform-switched implants seem to limit crestal bone remodeling.

Nonsurgical Treatment of Retrograde Peri-implantitis: A Case Report

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:36 +0200

The following report presents the treatment of a 53-year-old man that developed a radiolucency around the apex of the implant in the mandibular incisor region after placement and immediate provisionalization (nonfunctional loading). The radiolucency was detected during the final impression phase, 4 months after placement. A cone-beam computed tomographic scan revealed extensive involvement of the apical one third of the implant. The patient was placed on a course of antibiotics and monitored periodically over the next 12 months. The radiographic lesion gradually resolved over the following 9 months without further treatment. The patient remained asymptomatic throughout the course of final restorative therapy.

Fabrication of a Surgical Template for Orbital Implant Placement: A Case Report

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:35 +0200

Implant placement in orbital sites is challenging because of limited bone volume and poor bone quality. Preoperative optimal implant planning and intraoperative guides are important to ensure success. This article describes the use of computer simulation for implant insertion and fabrication of a surgical template as a drilling guide for orbital implant placement. A 29-year-old woman with a right orbital defect underwent computerized tomographic scanning, and the data were processed with interactive software to simulate orbital implant placement. A surgical template that served as a drilling guide was designed and fabricated to transfer orbital recipient site information from the three-dimensional computer model into the actual orbital implant sites. Three craniofacial implants were placed in the 7:00, 8:00, and 11:00 positions. No unexpected complications or injuries were encountered during the surgery. Magnetic abutments were attached to the implants 2 weeks later. The definitive facial prosthesis was fitted 6 months later, with excellent esthetic results. The surgical template contributed to the success of this treatment.

Reconstruction of Severely Resorbed Maxilla with Biodegradable Polylactide Screws: Case Series

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:34 +0200

Purpose: After the loss of natural teeth, bone changes in the jaws begin to take place immediately. Because the alveolar bone no longer responds to stresses placed in this area by teeth and periodontal ligaments, the bone begins to resorb. In such cases, alveolar bone reconstruction followed by implant-prosthetic treatment must be considered to reestablish esthetics and function. The present study was designed to compare and evaluate the effectiveness of titanium screws and absorbable fixation systems for the fixation of autogenous onlay bone grafts in maxillary reconstruction.
Materials and Methods: A total of 10 consecutive patients with severely resorbed maxillae were referred to the Oral and Maxillofacial Surgery Department at Piracicaba Dental School, Campinas State University (São Paulo, Brazil), for oral rehabilitation through implant placement. The bone defects were treated by autologous bone grafting from the iliac crest, which was fixed with absorbable screws. The patients were followed for a minimum of 6 months after prosthodontic work was concluded.
Results: The average age of the patients in this study was 46.9 years. Two dental implants were lost during the healing period. Four absorbable screws showed an unusual tissue reaction and were lost, and 90% of patients received the planned fixed prostheses. The implant success rate was 97% at 1 year after prosthesis placement.
Conclusion: Fixation with absorbable screws has been shown to be safe and predictable. The absorbable screws did not interfere with bone graft healing and dental implant osseointegration.

Maximum Use of the Anterior Maxillary Buttress in Severe Maxillary Atrophy with Tilted, Palatally Positioned Implants: A Preliminary Study

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:33 +0200

Purpose: To evaluate an alternative treatment for rehabilitation of the atrophic maxilla with palatal and tilted implants and to assess patient satisfaction with the results.
Materials and Methods: A retrospective case study was made of completely edentulous subjects with tilted, palatally positioned implants in the anterior maxillary buttress placed and loaded between January 2005 and January 2007. Patients with severely resorbed edentulous maxillae (Class V according to Cawood and Howell) who requested overdentures and were followed for 12 months after implant loading were included. Mesial and distal implant bone loss was measured on panoramic radiographs. Subjects indicated satisfaction with the new prosthesis after 12 months on a visual analog scale.
Results: Twelve patients treated with tilted and palatal implants in the anterior maxillary buttress were included in the study; 48 implants were placed (4 implants in each patient) to support 12 overdentures with bars. One implant failed, resulting in a survival rate of 97.9%. The mean peri-implant bone loss of implants with palatal anchorage after 1 year of loading was 0.78 ± 0.5 mm. All patients had stable prostheses at the end of the observation period. Patients were satisfied with comfort and stability, ability to speak, ease of cleaning, esthetics, and function of the prosthesis.
Conclusion: Placement of implants slightly to the palatal and tilted in the anterior maxillary buttress to support an overdenture with bars may be a viable treatment alternative for the rehabilitation of the atrophic maxilla, providing a high level of satisfaction with the prosthesis and reducing patient morbidity and costs.

Rehabilitation of the Nose Using CAD/CAM and Rapid Prototyping Technology After Ablative Surgery of Squamous Cell Carcinoma: A Pilot Clinical Report

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:31 +0200

Restoration of a nasal defect after ablative surgery for squamous cell carcinoma necessitates replacing the missing volume and anchoring a prosthesis to the patient’s face. This report describes the failure of plastic reconstructive surgery after ablation of a squamous cell cancer of the nose and the esthetic and functional restoration of the patient with a nasal prosthesis. The process of making an implant-supported prosthesis using digital technology, including digitized anatomic models from a “nose library," and the rapid prototyping of the mesiostructure for bar anchorage and of the mold for silicone processing are presented.

Vertical Ridge Augmentation with Autogenous Bone Grafts 3 Years After Loading: Resorbable Barriers Versus Titanium-Reinforced Barriers. A Randomized Controlled Clinical Trial

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:30 +0200

Purpose: To compare the efficacy of two different techniques for vertical bone regeneration at implant placement with particulated autogenous bone at 3 years after loading: resorbable collagen barriers supported by osteosynthesis plates and nonresorbable titanium-reinforced expanded polytetrafluoroethylene barriers.
Materials and Methods: Twenty-two partially edentulous patients requiring vertical bone augmentation were randomly allocated to two treatment groups, each composed of 11 patients. Prosthetic and implant failures, complications, the amount of vertically regenerated bone, and peri-implant marginal bone levels were recorded by independent and blinded assessors. The implant site requiring the most vertical bone regeneration was selected in each patient for bone level assessment. The follow-up time ranged from provisional loading to 3 years after loading. Analysis of covariance and paired t tests were conducted to compare means at the .05 level of significance.
Results: No patient dropped out or was excluded at the 3-year follow-up. No prosthetic failures and no implant failures or complications occurred after loading. There was no statistically significant difference in bone loss between the two groups at either 1 year or 3 years. Both groups had gradually lost a statistically significant amount of peri-implant bone at 1 and 3 years (P < .05). After 3 years, patients treated with resorbable barriers had lost a mean of 0.55 mm of bone; patients who had received nonresorbable barriers showed a mean of 0.53 mm of bone loss.
Conclusions: Up to 3 years after implant loading, no failures or complications occurred and peri-implant marginal bone loss was minimal. Vertically regenerated bone can be successfully maintained after functional loading.

Patient Satisfaction and Oral Health-Related Quality of Life Outcomes of Implant Overdentures and Fixed Complete Dentures

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:29 +0200

Purpose: To assess and compare patient satisfaction and oral health-related quality of life (OHQOL) in patients treated with implant-supported overdentures and complete implant fixed prostheses.
Materials and Methods: From a database of patients who had undergone implant treatment over a 6-year period, a study population of 62 patients was identified; every patient had at least four implants placed in one edentulous arch and was restored with either an overdenture or a fixed prosthesis. Patients were examined and a self-administered, structured multiple-response questionnaire, including the Oral Health Impact Profile-14 measurement tool and a patient satisfaction survey, was used to evaluate patient-centered treatment outcomes.
Results: Generally, patient satisfaction was very high in both the implant overdenture and fixed prosthesis groups, although the subjects in the overdenture group, who had mostly maxillary prostheses, reported significantly lower overall satisfaction and lower satisfaction with chewing capacity and esthetics. In just three categoriescost, satisfaction with treating doctor, and ability to perform oral hygiene measuresthe fixed prosthesis group was less satisfied than the removable overdenture group, but the difference was not significant. Similarly, the overall OHQOL was high, although patients receiving a fixed prosthesis demonstrated significantly lower psychologic discomfort and psychological disability compared to the overdenture group.
Conclusions: Among all patients who had similar numbers of implants placed, those who received an implant overdenture were less satisfied and had lower OHQOL than the patients who had a fixed prosthesis. Since patient and dentist preferences influenced the type of prosthesis provided, it is likely that subjective, patient-related factors are major determinants of satisfaction and treatment outcomes.

Immediate Loading of Two Freestanding Implants Retaining a Mandibular Overdenture: 1-Year Pilot Prospective Study

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:28 +0200

Purpose: The aim of this 1-year pilot prospective study was to evaluate the implant success rate, peri-implant tissue response, and complications associated with the immediate loading of two freestanding implants retaining mandibular overdentures.
Materials and Methods: Ten adults with a mean age of 59.7 years (range, 43 to 78 years) underwent treatment that included a maxillary removable complete denture opposing a mandibular removable overdenture retained by two freestanding, threaded, titanium oxide-surface implants with a 3-mm machined collar (n = 20 implants). The success of each implant was evaluated clinically and radiographically. Marginal bone levels and changes were evaluated using sequential standardized periapical radiographs. Surgical and prosthetic complications were recorded.
Results: Two patients, one with one failed implant, dropped out prior to completion of the study. The failed implants were included in the evaluation of cumulative implant success. The cumulative implant success rate at 1 year was 94% (16/17). The mean marginal bone loss was 1.12 ± 1.10 mm at 12 months. However, if the expected bone loss of 0.39 mm above the smooth-rough implant surface junction was considered, the mean marginal bone loss was only 0.73 mm. Mean Periotest values of -4.25 ± 0.93 at 1 year implied that osseointegration had been achieved for all successful implants. Modified Plaque Index scores of 0 and 1 were recorded throughout the duration of the study. No irreversible surgical and/or prosthetic complications were observed.
Conclusions: In this 1-year pilot prospective study, two immediately loaded unsplinted mandibular symphyseal implants retaining an overdenture resulted in favorable implant success and peri-implant tissue response.

The Effect of Miniscrew Taper Morphology on Insertion and Removal Torque in Dogs

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:27 +0200

Purpose: This study compared the insertion and removal torque of tapered and cylindric orthodontic miniscrews.
Materials and Methods: Ninety-six miniscrews were placed into the buccal alveolar bone of the mandible in six male beagle dogs. Maximum insertion torque was measured during placement of 48 miniscrews, and the maximum removal torque was recorded after 3 and 12 weeks of loading. After 4 months of healing, 48 additional miniscrews were implanted in almost the same place as the first set of implants; insertion torque was again measured. Histologic analysis was performed after 3 and 12 weeks of loading. Bone-implant contact and bone volume/total volume were compared during each period and in each group.
Results: The tapered miniscrews showed a higher mean maximum insertion torque (22.3 ± 3.2 Ncm) than the cylindric miniscrews (13.6 ± 2.0 Ncm) (P < .001). The mean maximum removal torque of the tapered miniscrews (9.1 ± 2.3 Ncm) was significantly higher than that of the cylindric miniscrews (5.7 ± 2.2 Ncm) at 3 weeks after placement (P < .05), but there was no significant difference in the mean maximum removal torque value between the tapered (4.2 ± 1.4 Ncm) and cylindric (3.0 ± 1.1 Ncm) implants after 12 weeks of loading. The percentage of bone-implant contact was similar between the groups after 3 weeks of loading and increased later. The percentage of bone volume/total volume was higher in the tapered miniscrews than in the cylindric miniscrews after 3 weeks of loading (P < .05), but there was no significant difference between the groups after 12 weeks of loading.
Conclusions: In this dog model, the tapered miniscrew design increased initial stability until 3 weeks of loading but had no additional effect on the secondary stability (ie, after 12 weeks of loading) versus a cylindric miniscrew design.

Comparison of Impression Techniques and Materials for an Implant-Supported Prosthesis

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:25 +0200

Purpose: To investigate, in vitro, the dimensional accuracy of two impression techniques (squared impression copings and squared impression copings sandblasted and coated with impression adhesive) made of vinyl polysiloxane and polyether impression materials.
Materials and Methods: A master cast (control group) with four parallel implant abutment analogs, a passive framework, and a custom aluminum tray was fabricated. Four groups (n = 5 each group) were tested: squared Impregum (SI), squared Express (SE), sandblasted adhesive squared Impregum (ASI), and sandblasted adhesive squared Express (ASE). The measurement method employed was just one titanium screw tightened to the framework. A stereomicroscope was used to evaluate the fit of the framework by measuring the size of the gap between the abutment and the framework. The results were analyzed statistically.
Results: The mean values for the abutment/framework interface gaps were: master cast, 31.63 µm (SD 2.16); SI, 38.03 µm (SD 9.29); ASI, 46.80 µm (SD 8.47); SE, 151.21 µm (SD 22.79); and ASE, 136.59 µm (SD 29.80). No significant difference was detected between the SI or ASI techniques and the master cast. No significant difference was detected between the SE and ASE techniques.
Conclusion: Within the limitations of this study, it can be concluded that Impregum Soft medium consistency was the best impression material and the impression technique did not influence the accuracy of the stone casts.

Bone Stress Analysis of Various Angulations of Mesiodistal Implants with Splinted Crowns in the Posterior Mandible: A Three-Dimensional Finite Element Study

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:24 +0200

Purpose: Ideally, implants for dental prostheses should be placed parallel to each other. However, anatomic limitations sometimes make nonparallel implants necessary. The purpose of this study was to determine the bone stresses on implants tilted at various angles and to determine what arrangements might carry a higher risk of failure.
Materials and Methods: Three-dimensional finite element models were constructed using the mean values measured for the Asian mandible in the first and second molar areas. Eight implants were divided into three tilting types: parallel implants (P1PP, P2MM, and P3DD), convergent implant apices (C1PD and C2MP), and divergent implant apices (D1DP, D2DM, and D3PM). A biting load of 200 N was applied vertically and obliquely on the occlusal central fossa of the splinted crowns. The main effects of each level of the three investigated factors (loading type, relationship of implant apices, and distal tilting of one or both implants) in terms of the stress values were computed for all models.
Results: The loading type was the main factor affecting the stress in bone when comparing implant apices and distal tilting of the implant body. When loading was combined with distal tilting, the stress values were significantly increased, especially in models P3DD and C1PD.
Conclusion: The loading type is the main factor affecting the stress distribution for different implantation arrangement. Moreover, placement of the implants with distal tilting should be avoided in the posterior mandible.

Immediate Loading as a Vehicle for Interdisciplinary Training in Implant Placement and Restoration

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:23 +0200

Recently, implant surgery has been introduced into postdoctoral prosthodontic programs; however, efficient training models to teach this have not been described to date. For training models to be effective and acceptable to all parties, a mutually beneficial situation must be created, and guidelines that can be followed easily need to be described. The purpose of this report is to suggest immediate loading of dental implants as an example for an interdisciplinary training model that integrates both the surgical aspects of implant therapy into the education of prosthodontic graduate students and the prosthodontic aspects of implant therapy into the training of periodontal graduate students. A flow chart of training steps is described for a patient treated with an immediately loaded mandibular fixed full-arch prosthesis on five interforaminal implants. Both the prosthodontic and the periodontal residents were involved in all phases of treatment. These postdoctoral students were in the final year of their program. Therefore, individual treatment steps could be taught interchangeably and accomplished by the student of the other specialty under the supervision of a clinical instructor. The unique characteristic of the immediate loading procedure, which includes surgical implant placement as well as immediate conversion of an existing denture into a fixed implant-supported provisional prosthesis, allows each postgraduate student to experience detailed surgical and prosthodontic treatment in a controlled environment on the day of surgery.

Impact of Abutment Rotation and Angulation on Marginal Fit: Theoretical Considerations

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:21 +0200

Purpose: Rotational freedom of various implant positional index designs has been previously calculated. To investigate its clinical relevance, a three-dimensional simulation was performed to demonstrate the influence of rotational displacements of the abutment on the marginal fit of prosthetic superstructures.
Materials and Methods: Idealized abutments with different angulations (0, 5, 10, 15, and 20 degrees) were virtually constructed (SolidWorks Office Premium 2007). Then, rotational displacement was simulated with various degrees of rotational freedom (0.7, 0.95, 1.5, 1.65, and 1.85 degrees). The resulting horizontal displacement of the abutment from the original position was quantified in microns, followed by a simulated pressure-less positioning of superstructures with defined internal gaps (5 µm, 60 µm, and 100 µm). The resulting marginal gap between the abutment and the superstructure was measured vertically with the SolidWorks measurement tool.
Results: Rotation resulted in a displacement of the abutment of up to 157 µm at maximum rotation and angulation. Interference of a superstructure with a defined internal gap of 5 µm placed on the abutment resulted in marginal gaps up to 2.33 mm at maximum rotation and angulation; with a 60-µm internal gap, the marginal gaps reached a maximum of 802 µm. Simulation using a superstructure with an internal gap of 100 µm revealed a marginal gap of 162 µm at abutment angulation of 20 degrees and rotation of 1.85 degrees. The marginal gaps increased with the degree of abutment angulation and the extent of rotational freedom.
Conclusions: Rotational displacement of the abutment influenced prosthesis misfit. The marginal gaps between the abutment and the superstructure increased with the rotational freedom of the index and the angulation of the abutment.

Critical Bending Moment of Four Implant-Abutment Interface Designs

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:20 +0200

Purpose: Critical bending moment (CBM), defined as the bending moment at which the external nonaxial load applied overcomes screw joint preload and causes loss of contact between the mating surfaces of the implant screw joint components, was measured for four different implants and their single-tooth replacement abutments.
Materials and Methods: CBM at the implant-abutment screw joint for four implant-abutment test groups was measured in vitro at 80%, 100%, and 120% of the manufacturers’ recommended torque levels. Regular-platform implants with their corresponding single-tooth abutments were used. Microstrain was measured while known loads were applied to the abutment at known distances from the implant-abutment interface. Strain instrumentation was used to record the strain data dynamically to determine the point of gap opening. All torque applications and strain measurements were repeated five times for the five samples in each group.
Results: For the Brånemark/CeraOne assemblies, the mean CBMs were 72.14 Ncm, 102.21 Ncm, and 119.13 Ncm, respectively, at 80%, 100%, and 120% of the manufacturer’s recommended torque. For the Replace/Easy assemblies, mean CBMs were 86.20 Ncm, 109.92 Ncm, and 120.93 Ncm; for the Biomet 3i/STA assemblies, they were 67.97 Ncm, 83.14 Ncm, and 91.81 Ncm; and for the Lifecore/COC assemblies, they were 58.32 Ncm, 76.79 Ncm, and 78.93 Ncm. Two-way analysis of variance revealed significant effects for the test groups and torque levels. Subsequent tests confirmed that significant differences existed between test groups and torque levels.
Conclusion: The results appear to confirm the primary role of the compressive preload imparted by the abutment screw in maintaining screw joint integrity. CBM was found to differ among implant systems and torque levels. Torque levels recommended by the manufacturer should be followed to ensure screw joint integrity.

The Effect of Increased Crown-to-Implant Ratio on Single-Tooth Locking-Taper Implants

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:19 +0200

Purpose: It has been proposed that increased crown heights lead to greater crestal stresses on dental implants, crestal bone loss, and other complications. The purpose of this study was to evaluate the effect of increased crown-to-implant ratio (C/IR) on single-tooth implants.
Materials and Methods: A retrospective cohort study was conducted between July 2001 and August 2003. The cohort was composed of patients who had at least one single-tooth Bicon implant restored with a cementless restoration and attended recall examinations in 2004, 2005, and 2007, during which several clinical and radiographic variables were documented. Descriptive statistics and univariate and multivariate mixed-effects regression models, adjusted for multiple implants in the same patient, were used.
Results: The cohort was composed of 81 subjects who received 326 Bicon implants. The mean duration of follow-up was 70.7 months. Mean change in the mesiodistal crestal bone levels was -0.33 mm. The mean C/IR was 1.6 (range, 0.79 to 4.95). Forty implant restorations (16%) had a C/IR ≥ 2. Implant restorations with increased C/IR were significantly more likely to have increased mesiodistal crown width, larger implant diameter, larger distance to mesial and distal adjacent structures, and deeper sulcular probings. Increased C/IR had a statistically significant effect in the loosening of maxillary anterior Integrated Abutment Crowns (Bicon) as well as a significant effect in the fracture of 2-mm-wide titanium abutment posts used to restore posterior areas. A C/IR up to 4.95 did not lead to an increased risk of crestal bone loss or to an increase in implant failures, crown failures, or crown fractures.
Conclusion: Larger C/IR was associated with a significant increase in prosthetic complications but had no significant effect on crestal bone levels on single-tooth locking-taper implants.

Analysis of the Attachment and Differentiation of Three-Dimensional Rotary Wall Vessel Cultured Human Preosteoblasts on Dental Implant Surfaces

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:18 +0200

Purpose: The purpose of this study was to determine whether osseous tissues engineered in three-dimensional (3D) environments preserved their mineralizing capacity and retained biologic characteristics when cultured on dental implant surfaces.
Materials and Methods: Human preosteoblast cells were cultured in both 3D rotary wall vessels and on 2D tissue culture plastic plates for 3 days. Aggregates from the 3D chambers and cells from the 2D plates were collected and transferred to commercially pure titanium disks with either 600-grit polished or sandblasted surfaces. These were cultured for an additional 7 days. The aggregates and cells from the disks were collected and prepared for scanning electron microscopy for microscopic evaluation and atomic adsorption assays for mineral content analysis. Additionally, staining with Alizarin red S was performed to compare the mineralization amount and pattern in each group. Polymerase chain reaction analysis was performed to evaluate expression of osteogenic genes, including Runx2, FAK, bone morphogenetic protein 2, and osteocalcin.
Results: Cells from 3D rotary wall vessel cultures attached to implant surfaces and presented cell attachment and growth patterns similar to those of standard 2D cultured cells, showing evidence of radial and random growth, yet they formed multiple focal niches on implant surfaces out of which cells proliferated. The 3D cultured cells and osseous tissues retained higher amounts of mineral formed during the initial culture and showed a higher tendency toward mineralization on implant surfaces compared to standard cultured cells. The 3D cultured cells and osseous tissues on implant surfaces at 1 week showed higher key gene protein expression. RNA expression at 1 week was equivalent to that of standard cultured cells.
Conclusion: Culture of human osteogenic cells and tissues in 3D rotary wall vessels may expedite the osseointegration process on dental implant surfaces, thus reducing the overall treatment time.

Accuracy of Impression Techniques for an Implant-Supported Prosthesis

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:17 +0200

Purpose: This in vitro study compared the dimensional accuracy of a stone index and of two impression techniques (squared impression copings and modified squared impression copings) for implant-supported prostheses.
Materials and Methods: A master cast with four parallel implant-abutment analogs and a passive framework were fabricated. Vinyl polysiloxane impression material was used for all impressions with a metal stock tray. Three groups of impressions were tested (n = 5): index (I), squared (S), and modified squared (MS). The measurement method employed was just one titanium screw tightened to the framework. The measurements (60 gap values) were analyzed using software that received the images from a video camera coupled to a stereomicroscope at 3100 magnification. The results were evaluated statistically (analysis of variance, Holm-Sidak method, a = .05).
Results: The mean abutment/framework interface gaps were: master cast = 31.63 µm; group I = 45.25 µm; group S = 96.14 µm; group MS = 51.20 µm. No significant difference was detected among the index and modified squared techniques (P = .05).
Conclusion: Under the limitations of this study, the techniques modified squared and index generated more accurate casts than the squared technique.

Effects of Cortical Bone Thickness and Implant Length on Bone Strain and Interfacial Micromotion in an Immediately Loaded Implant

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:15 +0200

Purpose: The aim of this study was to evaluate the effects of cortical bone thickness and implant length on strain in the surrounding bone and micromotion at the bone-implant interface in single immediately loaded implants.
Materials and Methods: Experiments with rapid prototyping technique and finite element simulations were performed to evaluate bone strain and micromotion at the bone-implant interface. Implants (13-mm long) were embedded into models with three thicknesses of cortical bone (0.5, 1.7, and 3.4 mm), and implants with different lengths (11.5 and 15.0 mm) were inserted into models with 1.7 mm of thickness of cortical bone. Vertical and lateral loads of 130 N were applied to the models.
Results: On lateral loading, the strains were highly concentrated on one side of the mandible in both experimental and finite element models. Sliding and gap distances were reduced when the cortical bone was thicker and when the implant was longer.
Conclusion: Placement of a longer implant into thicker cortical bone will result in reduced sliding and gap distances. However, bone strain is influenced more by the cortical bone thickness than by the implant length for single immediately loaded implants.

Three-Dimensional Culture of Mandibular Human Osteoblasts on a Novel Albumin Scaffold: Growth, Proliferation, and Differentiation Potential In Vitro

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:14 +0200

Purpose: Bone tissue engineering is a promising approach for bone reconstruction in oral and maxillofacial surgery. The aim of this study was to investigate the microstructure and biocompatibility of a novel albumin scaffold developed from human serum on human alveolar osteoblasts.
Materials and Methods: Samples of mandibular bone were obtained during routine oral surgery. Osteoblast cells were cultured and plated in a spongy, noncalcified protein scaffold prepared with plasmatic albumin crossed with a glutaraldehyde-type agent (study group) and in a large-particle mineralized cancellous allograft (control group). Measurement of the differentiation marker alkaline phosphatase and histologic examination were performed after 30 days of incubation. The cultures were examined for cell growth patterns and morphology by scanning electron microscopy and histomorphometry.
Results: Cultured osteoblasts showed comparable phenotypic profiles and expressed alkaline phosphatase in albumin scaffold. Hematoxylin-eosin staining revealed a bonelike extracellular matrix in study scaffold and mineralization of osteoblasts cultured in the albumin scaffold was confirmed by von Kossa staining.
Conclusion: Osteoblasts were able to proliferate in vitro and synthesize a bonelike extracellular matrix and mineralized tissue. The results indicate that this novel albumin scaffold is a favorable substrate for the growth and differentiation of osteoblasts and a promising material for bone tissue engineering and repair of bone defects.

Characterization of the Normal Bacterial Flora in Peri-implant Sulci of Partially and Completely Edentulous Patients

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:13 +0200

Purpose: To characterize the normal bacterial flora and evaluate the presence of periodontopathogenic bacteria around dental implants and to correlate them with the periodontal flora or, in completely edentulous patients, the alveolar gingival flora.
Materials and Methods: Clinical and radiographic parameters were recorded to exclude peri-implantitis in 34 partially edentulous and 19 completely edentulous patients. Partially edentulous patients were subdivided into two subgroups based on the depth of the periodontal pocket: ≤ 4 mm (n = 19) and > 4 mm (n = 15). Microbial samples were collected from peri-implant sulci, the deepest periodontal sulci, and, for completely edentulous patients, from the alveolar gingiva. Predominant aerobic bacteria were determined by microbiologic culturing, and multiplex polymerase chain reaction was used to detect five periodontopathogenic bacteria: Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Prevotella intermedia, and Actinobacillus actinomycetemcomitans.
Results: In all the examined patients, oral streptococci were the most frequent aerobic peri-implant bacteria. The frequency of four periodontopathogenic bacteria in tooth sulci (A actinomycetemcomitans, P gingivalis, T forsythensis, T denticola) was significantly higher around natural teeth with deeper periodontal pockets, but there was no significant difference in the frequency of the same bacteria in peri-implant sulci in the two partially edentulous subgroups. In contrast, there were no such bacteria in the peri-implant sulci or the alveolar gingiva of completely edentulous patients.
Conclusions: In healthy peri-implant sulci, oral streptococci constitute the predominant bacterial flora. In partially edentulous patients four periodontopathogenic bacteria were detected around implants, and none of these bacteria were found around implants in completely edentulous patients.

Study of an Experimental Microthreaded Scalloped Implant Design: Proximal Bone Healing at Different Interimplant Distances in a Canine Model

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:12 +0200

Purpose: The aim of the present study was to evaluate the validity of a new experimental microthreaded scalloped (MTS) implant design in comparison to a conventional flat-top (FT) implant by measuring the proximal bone loss at different interimplant distances in a canine model.
Materials and Methods: MTS implants were placed in one side of the posterior mandible and conventional flat-top (FT) implants were placed in the other side of the mandible in 10 beagle dogs. In five dogs, four each of the MTS and FT implants were placed with an interimplant distance of 2 mm. In another five dogs, three each of the MTS and FT implants were placed at an interimplant distance of 5 mm. All 70 implants (35 MTS and 35 FT implants) were placed in a nonsubmerged (one-stage) manner. The animals were sacrificed 4 months after implant placement, and the crestal bone levels around the MTS and FT implants were measured and compared on radiographs and histologic sections.
Results: The experimental MTS implants showed significantly less crestal bone loss (0.81 ± 0.34 mm) than the FT implants (1.60 ± 0.42 mm) on radiographs (P < .001). Histologic measurement also demonstrated that there was significantly less (P .05).
Conclusion: The experimental MTS implant was more effective in preserving the proximal bone than the conventional FT external-hex implant with the same surface. In this canine model, placement of the implants at either a 2-mm and or a 5-mm interimplant distance did not result in significant differences in marginal bone loss for both MTS and FT implants. This experiment demonstrated a potential benefit of the microthread design on a scalloped implant.

In Vivo Comparison of Bone Formation on Titanium Implant Surfaces Coated with Biomimetically Deposited Calcium Phosphate or Electrochemically Deposited Hydroxyapatite

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:11 +0200

Purpose: The purpose of this study was to investigate and compare bone formation on titanium implant surfaces coated with biomimetically deposited calcium phosphate (BDCaP) or electrochemically deposited hydroxyapatite (EDHA).
Materials and Methods: The implants were separated into three groups: a control group, a BDCaP group, and an EDHA group. Surface analysis was performed by field-emission scanning electron microscopy, x-ray diffractometry, and Fourier transform infrared spectroscopy. Implants were inserted in a randomized arrangement into rabbit tibiae. After 2, 4, and 8 weeks, the tibiae were retrieved and prepared for histomorphometric evaluation.
Results: Field-emission scanning electron microscopy showed that the BDCaP crystals were flakelike and the EDHA crystals were rodlike with a hexagonal cross section. X-ray diffractometric patterns and Fourier transform infrared spectroscopy spectra showed that the BDCaP coating consisted of HA and octacalcium phosphate, whereas the EDHA coating consisted of HA. Histologic observation showed that new bone on the EDHA-coated implant became mature after 4 weeks, while new bone on the control and BDCaP-coated implants was mature after 8 weeks. The EDHA implant showed significantly greater BIC and bone area compared to the control and BDCaP implants during 4 to 8 weeks. The BDCaP coating failed to show increased bone formation during the test period.
Conclusion: The present EDHA coating has good bone formation properties, while the BDCaP coating has weaker bone formation properties.

Thematic Abstract Review: CBCT AccuracyAn Update

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:10 +0200

Editorial: Rules and Regulations

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 15:02:09 +0200

Comparison of Two Piezoelectric Cutting Inserts for Lateral Bony Window Osteotomy: A Retrospective Study of 127 Consecutive Sites

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:23 +0200

Purpose: The aim of the present retrospective clinical study was to compare the efficacy of two piezoelectric cutting inserts for the incidence, size, and types of sinus membrane perforations, and to evaluate their various advantages for lateral window osteotomy.
Materials and Methods: The study consisted of 127 maxillary sinus augmentation procedures performed at two centers. A bony window was made on the lateral wall of the maxillary sinus with either the piezoelectric saw or the round diamond insert and repositioned over the bone graft as a homologous bony barrier. The rate of membrane perforation during sinus augmentation between the two groups was compared and analyzed statistically by the chi-square test and the two-sample t test.
Results: Seven perforations were seen in the 127 maxillary sinus procedures in this study (5.51%). Six perforations in 84 cases (7.14%) occurred with the piezoelectric saw and one perforation in 43 sites (2.32%) occurred while using the round insert. No statistically significant difference was found between the rates of membrane perforation between the two inserts.
Conclusion: The lateral bony window was created effectively with either of the two kinds of piezoelectric inserts. The membrane perforation rate was not significantly affected by the type of piezoelectric insert. The piezoelectric saw insert was more advantageous than the round diamond due to its greater precision and easier repositioning of the lateral bony window as a barrier.

A Prospective Randomized Clinical Study of Changes in Soft Tissue Position Following Immediate and Delayed Implant Placement

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:22 +0200

Purpose: The purpose of this investigation was to compare the efficacy of two therapeutic optionsimmediate implant placement and ridge preservation with delayed implant placementin maintaining the position of the soft tissue margins following tooth extraction.
Materials and Methods: This randomized controlled study evaluated apicocoronal changes in the midbuccal and proximal mucosal positions at implant placement sites from tooth extraction to 3 and 6 months following extraction. Twenty-four patients (26 sites) randomly received either immediate implant placement or ridge preservation (grafting with freeze-dried bone allograft and a collagen membrane) followed by implant placement 3 months later. Immediate placement sites received bone grafting for horizontal defects > 2 mm (from implant to cortical wall). Soft tissue measurements, vertical measurements, and ridge width measurements were performed and compared for immediate versus delayed implants and thin versus thick biotype.
Results: The midbuccal soft tissue margins showed minimal recession over 6 months from the time of extraction (mean 0.17 ± 0.47 mm), with no differences between treatment groups. Interproximal tissue height decreased significantly from extraction to 6 months (mesial, 1.73 ± 0.71 mm; distal, 1.48 ± 0.80 mm), with no significant differences between immediate and delayed placement. Immediate implant sites had greater reductions in ridge width 6 months after extraction than delayed placement sites. Tissue biotype failed to show any significant relationship with the changes identified.
Conclusions: This randomized controlled study comparing soft tissue changes following extraction failed to identify differences between patients treated with immediate or delayed approaches for midbuccal or interproximal soft tissue margins, although greater decreases in ridge width were observed in sites lacking bone grafting. Both immediate and delayed treatment approaches appear to be appropriate following tooth extraction, with the preferred treatment based on factors other than resultant soft tissue changes.

Bone Changes Around Early Loaded Chemically Modified Sandblasted and Acid-Etched Surfaced Implants With and Without a Machined Collar: A Radiographic and Resonance Frequency Analysis in the Canine Mandible

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:21 +0200

Purpose: The purpose of this study was to evaluate the radiographic bone level and stability changes around early loaded chemically modified sandblasted and acid-etched implants with and without a machined collar.
Materials and Methods: Seventy-two chemically modified sandblasted and acid-etched implants 4.1 mm in diameter and 8 mm in length were placed in six dogs. Thirty-six implants had no machined collar (NMC) and 36 had a 2.8-mm machined collar (MC). Resonance frequency measurements were obtained at placement and weekly for 3 weeks. All implants were loaded 21 days after surgery. Standardized periapical radiographs were obtained at baseline, at 3 weeks, and at 3, 6, 9, and 12 months. The radiographs were randomized and digitized, and linear measurements of the distance from the first bone-to-implant contact to the shoulder of the implant were performed at the mesial and distal aspects of each implant. For statistical analysis, mixed-model repeated-measures analysis of variance was used.
Results: All implants achieved hard and soft tissue integration clinically and radiographically and were clinically immobile. From placement to week 3, the mean implant stability increased for MC implants by more than 5 ISQs and for NMC implants by more than 7 ISQs. Radiographically, there were significant differences between treatment groups beginning at 3 months. After 12 months of loading, the MC implants presented a mean bone loss of 1.00 mm and the NMC implants presented a mean bone gain of 0.11 mm.
Conclusions: Chemically modified sandblasted and acid-etched implants without a machined collar presented bone gain, and implants with a machined collar showed bone loss after a 1 year following early (21-day) loading. The tendency toward a coronal apposition of bone observed under these conditions may be attributed to the osteoconductive properties of the chemically modified surfaces of these implants and to the absence of the machined collar.

Determination of Primary Stability: A Comparison of the Surgeons Perception and Objective Measurements

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:21 +0200

Purpose: To evaluate the difference between the dental surgeon’s perception of implant stability and the actual insertion torque and actual values obtained through resonance frequency analysis (RFA) during implant insertion surgery.
Materials and Methods: One hundred fifty-two patients who needed one or more dental implants were selected. A total of 514 Xive implants was inserted. For all 514 implants, after insertion, the oral surgeon was asked to indicate the probable RFA values (implant stability quotient [ISQ]). For 483 implants, the surgeon was also asked to indicate the probable insertion torque values (N/cm). The actual values were then measured. The RFA and insertion torque values were grouped into low, medium, and high groups.
Results: The mean perceived RFA was 72.2 ± 9.8 ISQ. The mean actual RFA was 73.5 ± 10.2 ISQ. This difference was statistically significant (P = .01). The mean perceived insertion torque was 39.1 ± 20.1 Ncm. The mean actual insertion torque was 39.9 ± 20.7 Ncm. The mean difference between actual and perceived ISQ values was -1 ± 14.9, with a range from -60 to 59; the mean difference between actual and perceived insertion torque values was -1.3 ± 9.9, with a range from -38 to 45.
Conclusions: Xive implants obtained good primary stability in many different clinical situations with a standard protocol. Primary stability is generally underestimated, especially in the presence of low or medium ISQ and torque values. The accuracy of primary stability prediction is not good enough to prevent mistakes when using an immediate loading technique; therefore, a more systematic use of objective measurements is encouraged.

Influence of Microgap Location and Configuration on Peri-implant Bone Morphology in Nonsubmerged Implants: An Experimental Study in Dogs

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:20 +0200

Purpose: It is unknown whether different microgap configurations can cause different peri-implant bone reactions. Therefore, this study sought to compare the peri-implant bone morphologies of two implant systems with different implant-abutment connections.
Materials and Methods: Three months after mandibular tooth extractions in six mongrel dogs, two oxidized screw implants with an external-hex connection were inserted (hexed group) on one side, whereas on the contralateral side two grit-blasted screw implants with an internal Morse-taper connection (Morse group) were placed. On each side, one implant was inserted level with the bone (equicrestal) and the second implant was inserted 1.5 mm below the bony crest (subcrestal). Healing abutments were inserted immediately after implant placement. Three months later, the peri-implant bone levels, the first bone-to-implant contact points, and the width and steepness of the peri-implant bone defects were evaluated histometrically.
Results: All 24 implants osseointegrated clinically and histologically. No statistically significant differences between the hexed group and Morse group were detected for either the vertical position for peri-implant bone levels (Morse equicrestal -0.16 mm, hexed equicrestal -0.22 mm, Morse subcrestal 1.50 mm, hexed subcrestal 0.94 mm) or for the first bone-to-implant contact points (Morse equicrestal -2.08 mm, hexed equicrestal -0.98 mm, Morse subcrestal -1.26 mm, hexed subcrestal -0.76 mm). For the parameters width (Morse equicrestal -0.15 mm, hexed equicrestal -0.59 mm, Morse subcrestal 0.28 mm, hexed subcrestal -0.70 mm) and steepness (Morse equicrestal 25.27 degree, hexed equicrestal 57.21 degree, Morse subcrestal 15.35 degree, hexed subcrestal 37.97 degree) of the peri-implant defect, highly significant differences were noted between the Morse group and the hexed group.
Conclusion: Within the limits of this experiment, it can be concluded that different microgap configurations influence the size and shape of the peri-implant bone defect in nonsubmerged implants placed both at the crest and subcrestally.

Allogeneic Bone Onlay Grafts for Alveolar Ridge Augmentation: A Systematic Review

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:19 +0200

Purpose: This systematic review examines the published findings on the clinical effectiveness and predictability of allogeneic bone blocks for the correction of alveolar ridge deformities to support dental implant placement in humans.
Materials and Methods: A bibliographic search was conducted of the MEDLINE and EMBASE databases for studies in which allogeneic block grafts were used for alveolar bone augmentation. The search was limited to human studies in English-language publications between 1950 and September 2008. Data extraction included the following outcomes: (1) vertical and/or horizontal bone gain/loss, (2) graft failure rate and complications, and (3) implant survival rate.
Results: The initial search identified 35 papers from the electronic databases, with nine publications meeting inclusion criteria: two case reports, six case series, and one prospective, multicenter, consecutive case series. No randomized controlled clinical trials were identified in the search. Observational studies (110 total patients) generally reported high rates of clinical graft incorporation (90% or greater) and implant survival (99% to 100%); however, the majority of reports involved selected defects in anterior regions with short-term follow-up (less than 3 years).
Conclusion: Clinical evidence remains limited to case series and reports that differ with respect to alveolar ridge defect selection, treatment, and endpoints of therapy over short-term follow-up periods. Although case-based reports document the potential for allogeneic block grafts to support alveolar ridge augmentation and implant placement, insufficient evidence is available to establish treatment efficacy relative to graft incorporation, alveolar ridge augmentation, and long-term dental implant survival.

Parameters of Implant Stability Measurements Based on Resonance Frequency and Damping Capacity: A Comparative Finite Element Analysis

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:19 +0200

Purpose: Contradictory results have been reported on the comparability of implant stability measurements performed with the Periotest and the Osstell Mentor devices. The purpose of the present finite element analysis was to simulate the influence of the parameters implant length, bone quality (cortical thickness and damping factor), bone loss, and quality of transducer fixation on resonance frequency analysis (RFA) and damping capacity measurements.
Materials and Methods: Three-dimensional finite element models of implants placed in human mandibular bone were designed for the simulation of Periotest (Periotest value; PTV) and RFA (implant stability quotient) measurements. Three values for each of the parameters implant length, damping capacity of cortical and trabecular bone, thickness of cortical bone, bone loss, and quality of transducer fixation were obtained. Measurements were simulated at four stages of osseointegration.
Results: For all parameters, an increase in implant stability was found with increasing levels of osseointegration. Implant stability was positively correlated with implant length and thickness of cortical bone, with slightly converging values at increased levels of osseointegration. Varying the damping factor of bone had no significant effect. Implant stability was negatively correlated with bone loss, with slightly converging values at increased levels of osseointegration. Linear changes in implant length and bone loss caused nonlinear effects in implant stability values. Stiffness of transducer fixation had an impact on RFA measurements when values below 10 GPa were applied.
Conclusion: Although both measuring devices reacted similarly when different parameters of implant stability were changed, good correlation between Periotest values and implant stability quotients was observed only when measurement values of implants without bone loss were considered.

Review of Dental Implant Rat Research Models Simulating Osteoporosis or Diabetes

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:18 +0200

Purpose: Osteoporosis and diabetes are physiologic determinants that affect the process of osseointegration. The demand for dental implants is high in these patients, who have benefited from progress in preclinical research. Osseointegration has been extensively studied in rat models of osteoporosis and diabetes. The aim of this study is to present an assessment of the published data and provide consideration for future studies.
Materials and Methods: The present study summarizes information through a systematic review of the literature from 1997 to 2008 available through PUBMED. The authors found 20 and 13 articles that report on osseointegration of implants in osteoporotic and diabetic rats, respectively. The survey was extended to recent publications on relevant aspects related to species, strains, and quality of endpoint data.
Results: Differences in experimental variables such as timing of implant insertion, location of implants, or duration of disease prior to implant placement were reported and can be justified based on the experimental questions. Moreover, heterogeneity was further caused by variations in the age of rats and in reporting of the main parameters of osseointegration in the cortical and medullary compartments. Regardless of these differences, the evidence indicates consistently that ovariectomy results in reduced osseointegration, while there is only moderate evidence for impaired osseointegration in diabetic rats.
Conclusions: Selection of the appropriate protocol is critical when studying implant osseointegration in rats. This overview highlights the demand for quality endpoint data related to animal numbers, data collection, and the way to establish osseointegration. Because of the differences in research questions, general recommendations for uniform models for osteoporosis and diabetes cannot be made.

Assessing the Fit of Implant Fixed Prostheses: A Critical Review

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:17 +0200

Purpose: This review critically compares the available clinical and laboratory methods for assessing the fit of an implant prosthesis.
Materials and Methods: MEDLINE and PubMed databases were searched for studies related to the fit of implant prostheses or the effect of misfit. Different combinations of key words were used. The screening procedure was performed in two stages. In the first stage, the relevant articles were selected. In the second stage, from those articles, specific inclusion and exclusion criteria were applied.
Results: Fifty-four articles were selected. Two different techniques were identified: in vitro and in vivo. The advantages, disadvantages, and limitations of each technique are discussed. There are clear limitations for the in vivo techniques. The in vitro techniques provide a more accurate measure of prosthesis misfit.
Conclusions: Because of the variety of techniques and the different parameters assessed by each, it is useful to combine several techniques to assess the accuracy of fit, quantify the effect of misfit, and subsequently determine an acceptable level of fit.

Multichannel Computed Tomography Versus Cone-Beam Computed Tomography: Linear Accuracy of In Vitro Measurements of the Maxilla for Implant Placement

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:16 +0200

Purpose: Accurate measurement of alveolar bone and adjacent anatomic structures is of paramount importance in implant insertion. This study was conducted to compare the linear measurement accuracy of 64-channel computed tomography (CT) and cone-beam CT (CBCT).
Materials and Methods: Twenty-seven sites were marked on three dry human skulls, with the positions of the buccal and palatal fiducial markers ensuring the representation of one plane by each buccal-palatal pair. The skulls were imaged using Somatom Sensation 64-channel CT (Siemens) and Pro Max 3D CBCT (Planmeca). The two fiducial markers and alveolar bone height were measured on the printed films of the cross-sectional views representing the best buccal and palatal markers. The maxillae were then sawed in marked locations, and direct measurements of the fiducial markers and alveolar bone height were then made. The Wilcoxon signed rank test was employed for statistical analysis.
Results: The measurement errors for the buccal fiducial markers, palatal fiducial markers, and crest height for CBCT were 0.38 ± 0.39 mm, 0.37 ± 0.33 mm, and 0.58 ± 0.45mm, respectively; for the 64-channel CT they were 0.59 ± 0.61 mm, 0.37 ± 0.42 mm, and 0.72 ± 0.92 mm, respectively. There was no statistically significant difference in measurement error between the two methods (P > .05).
Conclusion: There was no statistically significant difference in terms of linear measurement accuracy between the two systems; it could, therefore, be concluded that CBCT is a useful tool for a preliminary assessment of anticipated implant sites.

Comparison of the Accuracy of Invasive and Noninvasive Registration Methods for Image-Guided Oral Implant Surgery

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:15 +0200

Purpose: Registration refers to the linkage of coordinates from an image with actual patient coordinates and has been shown to be the most influential factor in the accuracy of image-guided surgery. Invasive bone markers are the gold standard but require surgical placement prior to imaging. In contrast, registration templates or external registration frames are noninvasive, but their repositioning during imaging and surgery can be a source of error. The purpose of the present study was to determine whether noninvasive registration methods can achieve an accuracy similar to that of invasive bone marker registration.
Materials and Methods: Computed tomographic slices (1 mm each) of a maxillary and mandibular dental stone cast that had been prepared with target markers on the buccal and oral surfaces were registered with an optical-based navigation system simulating invasive bone markers, noninvasive registration templates, and a noninvasive external registration frame. Predicted error of the navigation system, fiducial registration error, and target registration error were evaluated. The use of five and seven registration markers was compared.
Results: A total of 696 error measurements was performed. The external registration frame showed significantly worse fiducial registration error compared with the other methods, but there was no significant difference in target registration error between invasive and noninvasive registration methods. The predicted error given by the navigation system significantly underestimated target registration error. Increasing the number of registration markers from five to seven resulted in no significant differences.
Conclusions: Noninvasive registration based on registration templates or external registration frames showed accuracy that was equivalent to that of invasive registration. The use of five registration markers was sufficient. The predicted error given by a navigation system should not be mistaken as “navigation error" during clinical application.

Morphologic Classification and Stress Analysis of the Mandibular Bone in the Premolar Region for Implant Placement

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:15 +0200

Purpose: The objective of this study was to assess the influence of mandibular morphology on the stress and strain distributions in the bone supporting an implant.
Materials and Methods: Subjects were selected from patients with missing mandibular premolar teeth. Computed tomographic scans of the premolar region were classified into nine groups based on the overall bone morphology and the relative position of the alveolar crest. Finite element models of the bone on the basis of this classification, with inserted implants and superstructures, were constructed. A load of 200 N applied 30 degrees buccal from the vertical axis was directed toward the occlusal surface.
Results: One hundred two partially (n = 98) and completely (n = 4) edentulous subjects were recruited. Their ages ranged from 40 to 79 years (mean age, 60.5 years; 41 men and 61 women). Approximately 56% of the patients showed bone widening in the caudal direction. The maximum compressive stresses were shown in the lingual cervical regions. An influence of overall bone morphology on stress distribution was not observed; however, the alveolar crest contour clearly affected the maximum stress and strain values. Compressive microstrain above 4,000 was observed only when the alveolar crest was lingually located relative to the body of the mandible. These high strain levels were concentrated at the lingual cervical margin, with volumes ranging from 0.04 to 0.07 mm3.
Conclusion: The contour of the alveolar crest potentially plays a critical role in maintaining the bone levels surrounding implants.

The Effects of Different Loading Times on the Bone Response Around Dental Implants: A Histomorphometric Study in Dogs

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:14 +0200

Purpose: The aim of this study was to evaluate, through histomorphometric analysis, the effect that different loading times would have on the bone response around implants.
Materials and Methods: Three Replace Select implants were placed on each side of the mandible in eight dogs (n = 48 implants). One pair of implants was selected for an immediate loading protocol (IL). After 7 days, the second pair of implants received prostheses for an early loading protocol (EL). Fourteen days after implant placement, the third pair of implants received prostheses for advanced early loading (AEL). Following 12 weeks of prosthetics, counted following the positioning of the metallic crowns for the AEL group, the animals were sacrificed and the specimens were prepared for histomorphometric analysis. The differences between loading time in the following parameters were evaluated through analysis of variance: bone-to-implant contact, bone density, and crestal bone loss.
Results: The mean percentage of bone-to-implant contact for IL was 77.9% ± 1.71%, for EL it was 79.25% ± 2.11%, and for AEL it was 79.42% ± 1.49%. The mean percentage of bone density for IL was 69.97% ± 3.81%, for EL it was 69.23% ± 5.68%, and for AEL it was 69.19% ± 2.90%. Mean crestal bone loss was 1.57 ± 0.22 mm for IL, 1.23 ± 0.19 mm for EL, and 1.17 ± 0.32 mm for AEL. There was no statistical difference for any of the parameters evaluated (P > .05).
Conclusion: Different early loading times did not seem to significantly affect the bone response around dental implants.

Microgap Between Zirconia Abutments and Titanium Implants

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:13 +0200

Purpose: The aim of this study was to evaluate in vitro the microgap between different zirconia abutments and their titanium implants.
Materials and Methods: Four systems were evaluated: Procera zirconia (Nobel Biocare) (Nb), Cercon Balance Anterior (Dentsply Friadent) (Ba), ZirDesign (Astratech) (Zd), and Straumann Cares ceramic (Straumann) (Ca). Five assemblies were assessed for each system. The assemblies were embedded in epoxy, cut along their long axes, and polished. Scanning electron microscopic observations were made along the first 100 µm of the gap on each side at maximal magnification. Images were combined and gap measurements were made 10 µm apart. A two-way analysis of variance was performed on the data.
Results: Scanning electron micrographs showed a mean marginal microgap of 0.89 µm (SD 1.67) for all assemblies. Significant differences (P < .001) were observed between mean (± SD) microgap measurements of the four tested systems: Ba = 0.38 ± 0.28 µm; Zd = 0.55 ± 0.23 µm; Nb = 1.83 ± 3.21 µm; Ca = 0.90 ± 0.59 µm. The mean microgap of the first 20 µm of the outer region (1.66 µm) was significantly (P < .001) larger than the mean microgap (0.56 µm) of the inner region (30 to 100 µm).
Conclusions: Within the limitations of this study, the mean microgap observed for all tested systems was less than 2 µm. For each system, the microgap decreased quickly from the outer region to the inner. The mean gap was larger for flat-to-flat connection systems, compared to internal-connection systems with a conical interface. These results demonstrate smaller microgaps compared to those described in the literature for titanium abutments. The precise fit of these abutments could lead to better biologic and biomechanical behavior.

Evaluation of Multiple Implant-Bone Parameters on Stress Characteristics in the Mandible Under Traumatic Loading Conditions

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:13 +0200

Purpose: The inter-relationships between various implant and bone parameters were evaluated for their influence on the von Mises stress distribution within the mandible using the finite element procedure. The maximum compressive stresses in cancellous and cortical bone were compared to the published stress-strain data to determine bone fracturing status when the maximum (traumatic) loading is applied.
Materials and Methods: Parameters considered herein include the implant diameter and length. Also considered are Young’s modulus of cancellous bone and that of cortical bone, along with its thickness. The implant-bone system was modeled using two-dimensional plane strain elements, 50% osseointegration between implant and cancellous bone was assumed, and linear relationships were assumed between the stress value and Young’s modulus of both cancellous and cortical bone at any specific point within the mandible.
Results: Implant length was more influential than implant diameter within cancellous bone, whereas implant diameter was more influential in cortical bone. A ranking of all the parameters indicated that the applied masticatory force had a more significant influence on the stress difference, in both cancellous and cortical bone, than all other parameters. Young’s modulus of cortical bone and implant length were least influential in cancellous and cortical bone, respectively. Under traumatic loading, cancellous bone fractured for all parameter combinations. When all parameters were set to their average values, the cortical bone did not fracture under traumatic loading. However, it fractured if all the parameters were all set to the minimum values.
Conclusion: Quantitative evaluation and ranking of the major implant and bone parameters will help provide practical guidelines that are useful for the design and testing of dental implants. The study may also be of interest to dental professionals in evaluating possible implant placement options under various clinical scenarios.

Thematic Abstract: Status Update: “Short Implants” Outcomes

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:12 +0200

Editorial: When Silver Touches Titanium

Quintessenz Verlag Berlin — Thu, 29 Jul 2010 11:02:11 +0200

Paraneoplastic pemphigus characterized by polymorphic oral mucosal manifestations – Report of two cases

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 19:02:23 +0200

A long-term laboratory test on staining susceptibility of esthetic composite resin materials

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 19:02:23 +0200

In vitro study of the correlation between the simulated clinical and radiographic examination of microgaps at the implant-abutment interface

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 19:02:22 +0200

The impact of nonautogenous bone graft on orthodontic treatment

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 19:02:21 +0200

Audiovisual video eyeglass distraction during dental treatment in children

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 19:02:21 +0200

Follicular lymphoma in the palate with clinical appearance similar to salivary gland tumors

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 19:02:20 +0200

Immediate definitive rehabilitation of the edentulous patient using an intraorally welded titanium framework: A 3-year prospective study

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 19:02:19 +0200

Bismuth subgallate as a topical hemostatic agent at palatal donor sites

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 15:02:11 +0200

A comparative study of bone densitometry during osseointegration: Piezoelectric surgery versus rotary protocols

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 15:02:10 +0200

Prospective study of zirconia-based restorations: 3-year clinical results

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 15:02:09 +0200

Dental caries in an impacted mandibular second molar: Using cone beam computed tomography to explain inconsistent clinical and radiographic findings

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 15:02:09 +0200

Guest Editorial: Diagnosis and Treatment of Temporomandibular Disorders: Emergence of a New “Standard of Care”

Quintessenz Verlag Berlin — Tue, 27 Jul 2010 15:02:08 +0200

A retrospective study of edentulous patients rehabilitated according to the ‘all-on-four’ or the ‘all-on-six’ immediate function concept using flapless computer-guided implant surgery

Quintessenz Verlag Berlin — Fri, 09 Jul 2010 11:03:20 +0200

Purpose: To report the outcome of an implant therapy protocol using 4 or 6 implants supporting immediately loaded fixed prostheses following 3D software planning and flapless guided surgery.
Materials and methods: A total of 30 patients (24 women, 6 men), mean age of 53 years (range 35-84 years) were treated with 195 immediately loaded implants (97 NobelSpeedy Groovy and 98 Brånemark MKIII Groovy) supporting 25 maxillary and 17 mandibular fixed full-arch acrylic prostheses and followed for 1 year. The Procera Software v1.6 and v2.0 was used to plan implant position and to obtain a surgical template for the guided flapless implant placement. To perform immediate loading, the implants had to be inserted with torque of at least 35 Ncm. Provisional prostheses were made before surgery using software planning and were placed in the same session as the implants. Definitive restorations were delivered 6-12 months after surgery. Outcome measures were failures of the prosthesis and of the implants, marginal bone level changes, complications, clinical time and patient satisfaction.
Results: Four patients with full edentulism and 26 with advanced periodontitis were enrolled in this study. A total of 195 implants were immediately loaded (128 implants were placed in the maxilla and 67 implants were placed in the mandible). Four implants out of 195 failed in three patients during the healing period: 2 in the maxilla (1 straight and 1 tilted), and 2 in the mandible (both of them tilted). Three of them were successfully replaced. One year after loading there were no dropouts and no failure of the definitive prosthesis occurred. In three cases, the surgical template fractured during surgery. In one patient, a new impression had to be taken to fit the provisional prosthesis onto the implants. Three patients were subjected to surgery and systemic antibiotics to treat apically infected implants.
Conclusions: The all-on-four’ and all-on-six’ treatment protocol combined with computer-guided flapless implant surgery could be a viable and predictable treatment. Some complications occurred that were successfully treated. However, this technique could be sensitive to the experience of the surgeon and a learning curve is required.

Markers of systemic inflammation in periodontal patients: chronic versus aggressive periodontitis. An explorative cross-sectional study

Quintessenz Verlag Berlin — Fri, 09 Jul 2010 11:03:19 +0200

Aim: The aim of this study was to evaluate differences in the inflammatory profile of young (≤40 years) systemically healthy periodontal patients comparing chronic (CP) versus aggressive periodontitis (AP) in terms of cytokines, chemokines and C-reactive protein levels.
Methods: Systemically healthy subjects affected by severe CP or AP were enrolled in this study. Differential diagnosis was performed according to the criteria suggested by the American Academy of Periodontology. Blood samples for the evaluation of high sensitivity C-reactive protein levels, cytokine levels (IL-1β, IL-1RA, IL-4, IL-6, IL-10, IL-12, interferon-γ, interferon-γ-inducible protein 10, tumour necrosis factor α) and chemokine levels (IL-8, vascular endothelial growth factor, monocyte chemoattractant protein 1, macrophage inflammatory protein 1α and macrophage inflammatory protein 1β) were obtained from all patients.
Results: A total of 45 systemically healthy patients with severe periodontitis were consecutively selected, 21 with CP (mean age 36.8 ± 3.5; mean clinical attachment level [CAL] 4.72 ± 0.69) and 24 with AP (mean age 35.9 ± 3.8; mean CAL 4.68 ± 0.75). No statistically significant difference between the two groups was detected for periodontal variables and for all the investigated inflammatory markers.
Conclusions: The inflammatory profile of severe periodontitis in young patients (≤40 years) may be similar for chronic and aggressive types. Differential diagnosis between CP and AP may not be able to detect a different systemic inflammatory profile in young adults.

Effectiveness of prophylactic antibiotics at placement of dental implants: a pragmatic multicentre placebo-controlled randomised clinical trial

Quintessenz Verlag Berlin — Fri, 09 Jul 2010 11:03:19 +0200

Purpose: To evaluate the efficacy of prophylactic antibiotics for dental implant placement.
Materials and methods: Thirteen dentists working in private practices agreed to participate in this trial, each centre providing 50 patients. One hour prior to implant placement, patients were randomised to take orally 2 g amoxicillin or identical placebo tablets. Patients needing bone augmentation at implant placement were not included. Outcome measures were prosthesis and implant failures, adverse events and post-operative complications. Patients were seen 1 week, 2 weeks and 4 months post-operatively.
Results: Two centres did not deliver any data, two centres did not manage to include the agreed quota of patients and three patients had to be excluded. Two-hundred and fifty-two patients were evaluated in the antibiotic group and 254 in the placebo group, and none dropped out at 4 months. Four prostheses and seven implants (in five patients) failed in the antibiotics group versus 10 prostheses and 13 implants (in 12 patients) in the placebo group. Eleven complications were reported in the antibiotic group versus 13 (in 12 patients) in the placebo group. No side effects were reported. There were no statistically significant differences for prosthesis failures, implant losses and complications. Patients receiving immediate post-extractive implants had an increased failure risk compared with patients receiving delayed implants (9% versus 2%).
Conclusions: No statistically significant differences were observed, although trends clearly favoured the antibiotic group. Immediate post-extractive implants were more likely to fail.

The influence of platelet-rich plasma on the healing of extraction sockets: an explorative randomised clinical trial

Quintessenz Verlag Berlin — Fri, 09 Jul 2010 11:03:18 +0200

Purpose: To investigate the effect of platelet-rich plasma (PRP) on the healing of hard and soft tissues of extraction sockets with a pilot study.
Material and methods: Patients undergoing tooth extraction under intravenous sedation were asked to participate in the trial. Autologous platelet concentrates were prepared from the patients’ blood and autologous thrombin was produced. Outcome measures were: pain level, analgesic consumption, oral function (ability to eat food, swallowing, mouth opening and speech), general activity, swelling, bruising, bleeding, bad taste or halitosis, food stagnation, patient satisfaction, healing complications, soft tissue healing, trabecular pattern of newly formed bone in extraction sockets, trabecular bone volume, trabecular separation, trabecular length, trabecular width, and trabecular number. Patients were followed up to 3 months post-extraction.
Results: Twelve patients (15 sockets) were randomly allocated to the PRP group and 11 patients (14 sockets) to the control group. Two patients from the control group did not attend any of the scheduled appointments following tooth extraction, and were considered dropouts. Additionally, one more patient from the control group and four patients from the PRP group did not attend their 3-month radiographic assessment appointments. Statistically significantly more pain was recorded in the control group for the first (P = 0.02), second (P = 0.02) and third (P = 0.04) post-operative days for Visual Analogue Scale scores, whereas no differences were observed for the fourth (P = 0.17), fifth (P = 0.38), sixth (P = 0.75) and seventh (P = 0.75) post-operative days. There was a statistically significantly higher analgesic consumption for the first (P = 0.03) and second (P = 0.02) post-operative days in the control group and no differences thereafter. Differences in patients’ responses in the health-related quality of life questionnaire were statistically significant in favour of PRP treatment only for the presence of bad taste or bad smell in the mouth (P = 0.03), and food stagnation in the operation area (P = 0.03). The difference between groups was not statistically significant for patient satisfaction with the treatment (P = 0.31). Regarding complications, two dry sockets and one acutely inflamed alveolus occurred in patients of the control group, which determined a borderline statistically significant difference in favour of the PRP group (P = 0.06). Soft tissue healing was significantly better in patients treated with PRP (P = 0.03). Radiographic evaluation carried out by the two blinded examiners revealed a statistically significant difference (P = 0.01) for sockets with dense homogeneous trabecular pattern, a borderline statistically significant difference in the trabecular pattern for bone volume (P = 0.06) favouring PRP use, and no significant differences for trabecular separation (P = 0.66), trabecular length (P = 0.16), trabecular width (P = 0.16) and trabecular number (P = 0.38).
Conclusions: PRP may have some benefits in reducing complications such as alveolar osteitis and improving healing of soft tissue of extraction sockets. There were insufficient data to support the use of PRP to promote bone healing or to enhance the quality of life of patients following tooth extraction, although the sample size was too small to detect statistically significant differences.

Immediate occlusal versus non-occlusal loading of single zirconia implants. A multicentre pragmatic randomised clinical trial

Quintessenz Verlag Berlin — Fri, 09 Jul 2010 11:03:17 +0200

Purpose: To evaluate whether immediate non-occlusal loading of single zirconia implants could reduce early failures when compared to immediate occlusal loading.
Materials and methods: Forty partially edentulous patients who received one single zirconia implant (Z-Systems) at least 10 mm long and 3.25 mm wide inserted with a torque of at least 35 Ncm were randomised to immediate occlusal or non-occlusal loading groups. All patients received provisional acrylic crowns the same day of implant placement. Provisional crowns were replaced after 4 to 5 months by definitive full ceramic crowns. Outcome measures were implant success, any complications and peri-implant marginal bone levels.
Results: One year after loading, no patients had dropped out. Five implants (12.5%) failed early: three occlusally loaded and two non-occlusally loaded. Three complications occurred, all after delivery of the definitive crowns: one crown fractured (occlusal loading), one had to be remade after debridement because of hyperplastic tissues (occlusal loading), and one crown decemented (nonocclusal loading). These differences were not statistically significant. Both groups gradually lost periimplant bone in a highly statistically significant way. One year after loading, patients subjected to non-occlusal loading lost an average of 0.7 mm of peri-implant bone versus 0.9 mm in the occlusal group. This difference in bone loss between groups was not statistically significant. There was an association between immediate post-extractive implants and implant failures (P = 0.01). Four of the 10 immediate post-extractive implants (40%) failed versus one out of 30 delayed implants (3%).
Conclusions: The results of this study do not provide a conclusive answer to whether immediate non-occlusal loading may decrease implant failures. Immediately loaded zirconia implants placed in post-extractive sites had high failure rates.

Does antibiotic prophylaxis at implant placement decrease early implant failures? A Cochrane systematic review

Quintessenz Verlag Berlin — Fri, 09 Jul 2010 11:03:17 +0200

Conflict-of-interest statement: Marco Esposito is the first author of two of the included studies; however, he was not involved in the quality assessment of these trials. This review is based on a Cochrane systematic review entitled Interventions for replacing missing teeth: antibiotics at dental implant placement to prevent complications’ published in The Cochrane Library (see http://www.cochrane.org for more information). Cochrane systematic reviews are regularly updated to include new research, and in response to comments and criticisms from readers. If you wish to comment on this review, please send your comments to the Cochrane website or to Marco Esposito. The Cochrane Library should be consulted for the most recent version of the review. The results of a Cochrane Review can be interpreted differently, depending on people’s perspectives and circumstances. Please consider the conclusions presented carefully. They are the opinions of the review authors, and are not necessarily shared by the Cochrane Collaboration.
Purpose: To assess the beneficial or harmful effects of systemic prophylactic antibiotics at dental implant placement versus no antibiotic/placebo administration and, if antibiotics are of benefit, to find which type, dosage and duration is the most effective.
Materials and methods: The Cochrane Oral Health Group’s Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched up to 2 June 2010 for randomised controlled clinical trials (RCTs) with a follow-up of at least 3 months comparing the administration of various prophylactic antibiotic regimens versus no antibiotics to patients undergoing dental implant placement. Outcome measures were prosthesis failures, implant failures, postoperative infections and adverse events (gastrointestinal, hypersensitivity, etc.). Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Meta-analyses were conducted.
Results: Four RCTs were identified: three comparing 2 g of preoperative amoxicillin versus placebo (927 patients) and the other comparing 1 g of preoperative amoxicillin plus 500 mg four times a day for 2 days versus no antibiotics (80 patients). The meta-analyses of the four trials showed a statistically significantly higher number of patients experiencing implant failures in the group not receiving antibiotics: risk ratio = 0.40 (95% confidence interval (CI) 0.19 to 0.84). The number needed to treat (NNT) to prevent one patient having an implant failure is 33 (95% CI 17-100), based on a patient implant failure rate of 5% in patients not receiving antibiotics. The other outcomes were not statistically significant, and only two minor adverse events were recorded, one in the placebo group.
Conclusions: There is some evidence suggesting that 2 g of amoxicillin given orally 1 h preoperatively significantly reduce failures of dental implants placed in ordinary conditions. No significant adverse events were reported. It might be sensible to suggest the use of a single dose of 2 g prophylactic amoxicillin prior to dental implant placement. It is still unknown whether post-operative antibiotics are beneficial, and which is the most effective antibiotic.

Editorial: EJOI is on PubMed!

Quintessenz Verlag Berlin — Fri, 09 Jul 2010 11:03:15 +0200

Hyperplastic Dental Follicle – Review of Literature and Report of Two Cases in One Family

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:18 +0200

Hyperplastic dental follicle is an extremely rare lesion. The practitioner should be able to differentiate it from a dentigerous cyst. The present article will review related literature and report on two cases in one family. A 12-year-old white female and her 15-year-old brother were referred for exposure of unerupted canines. No systemic diseases or syndromes were present. Intra-oral examinations were unremarkable, except for the absence of all eight canines. Radiographic examinations revealed impacted canines with each unerupted tooth surrounded by a well-demarcated radiolucency, which passed beyond the cementoenamel junction. The teeth were surgically exposed and tissue specimens surrounding the unerupted teeth were analysed histologically. Histology revealed fibrous connective tissue with areas demonstrating some ground substance and multiple odontogenic epithelial rests. Some surfaces were partially lined by reduced enamel epithelium. A diagnosis of hyperplastic dental follicle was made. Sometimes, it is difficult to differentiate hyperplastic dental follicle from odontogenic fibroma, both simple and central forms. A correct diagnosis should be based on clinical, radiographic and histological findings.

One-stage Operation for Norma-induced Bilateral Ankylosis Accompanied with Mouth Verrucous Carcinoma – a Case Report and Review of Literature

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:18 +0200

A rare case of a male patient who suffered from noma with sequelae of ankylosis in bilateral temporomandibular joints for 52 years and a neoplasm in the right commissure of the lips for 1 year, was operated on to resolve the ankylosis, remove the neoplasm and reconstruct the soft tissue defect with a forearm flap through a one-stage operation. The neoplasm pathology was verrucous carcinoma.

Multiple Retentive Means for Prosthetic Restoration of a Large Facial Defect – a Case Report

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:17 +0200

A 70-year-old man who suffered from extensive extra and intraoral defects was rehabilitated with a prosthesis using multiple retaining means. The treatment was performed in two parts: externally involving the construction of an episthesis supported only by the remaining intact boundaries of the defect and retained by mini-dental implants and spectacle frame with a modified ear hook; and intraorally by an acrylic resin obturator to restore the function of the hemi-sectioned hard and soft palate. The episthesis was securely retained with minimal movement and/or dislodgment of the prosthesis during function. Multiple retentive techniques may be used to fix heavy external prostheses as an alternative to conventional implants or biological adhesives.

Progress of Oral Sequelae During Head-Neck Radiotherapy

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:16 +0200

Objective: To evaluate xerostomia, mucositis and dental caries during head and neck radiotherapy.
Methods: Twenty patients with nasopharyngeal carcinoma were included. Oral examinations were conducted before radiotherapy, after dosage of 2000 cGy irradiation, immediately after the termination of radiotherapy, and 1 month and 6 months after termination of the radiotherapy. Oral hygiene instruction, effective oral care and dental intervention were performed during the treatment. Salivary flow rate was evaluated by modified Schirmer’s test. Xerostomia, mucositis and dental caries status were evaluated based on oral examinations.
Results: Salivary flow rate decreased significantly after the first dosage of 2000 cGy, and was aggravated with the increase in irradiation dosage until the termination of radiotherapy. Xerostomia and mucositis were observed in parallel with the reduction of saliva flow rate, and were aggravated with the increase in irradiation dosage. Mucositis began to recover within 1 month after the termination of radiotherapy and fully recovered within 6 months after the termination of the radiotherapy. Six months after the termination of irradiation, new carious lesions were detected in two patients.
Conclusion: Oral sequelae developed during radiotherapy of the head and neck. Oral health instructions and effective intervention were essential before, during and after the radiotherapy.

Prevalence of Traumatic Dental Injuries to Permanent Incisors Among 12-year-old School Children in Davangere, South India

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:16 +0200

Objective: To assess the prevalence and factors associated with traumatic injuries to permanent incisors of 12-year-old school children in Davangere, India.
Methods: In total, 1020 12-year-old school children were selected. Two trained and calibrated clinicians examined the children in the school environment using the World Health Organization Classification of Tooth Fracture (1978). Examination was also done for lip coverage and maxillary overjet using the Community Periodontal Index probe. Children were then interviewed using a structured questionnaire for demographic data and history of the injury.
Results: The overall prevalence rate of traumatic dental injuries (TDI) to permanent incisor teeth was 15.1%. The prevalence of TDI was higher in boys compared to girls. The major cause of TDI was falling followed by collision. The maxillary incisors were commonly injured, involving mainly enamel fracture. Children with excessive overjet and inadequate lip coverage were more likely to have injuries.
Conclusion: TDI could be a serious dental public health problem among children. Thus, there is an urgent need to collect local data on dental injuries in order to obtain a more comprehensive picture of dental health.

Involvement of Notch Signalling Pathway in Senescence of Human Dental Pulp Cells

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:15 +0200

Objective: To evaluate whether the Notch signalling pathway is involved in the senescence of human dental pulp cells.
Methods: Human dental pulp cells were isolated and cultured. The Notch signalling pathway was blocked by adding DAPT (N-[N-(3,5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester, γ-secretase inhibitor, 5 μmol/L) into the culture medium. Cell proliferation was evaluated by MTT assay. Cell senescence was evaluated through expression of senescenceassociated β-galactosidase (SA-β-Gal) using β-galactosidase staining.
Results: The proliferation of the human dental pulp cells decreased dramatically after treatment with DAPT, compared with the control. SA-β-Gal positive staining cells were seen in the DAPT group, but not in the control group.
Conclusion: The Notch signalling pathway is involved in the senescence of human dental pulp cells.

Efficacy of Functional Training of the Facial Muscles for Treatment of Incomplete Peripheral Facial Nerve Injury

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:15 +0200

Objective: To investigate the efficacy of functional training of facial mimic muscles for patients with incomplete peripheral facial nerve injury.
Methods: Ninety-two patients with 241 injured branches of incomplete peripheral facial nerve injury were divided into a treatment group and a control group. The treatment group consisted of 58 cases that received functional training of facial mimic muscles. The rest of the cases served as controls. Assessment parameters included the House-Brackmann grading system, a quantitative facial nerve function estimating system and electroneurography. According to the three assessments, the facial nerve injury was divided into four grades: normal, minor, moderate and severe. The treatment group started training facial mimic muscle activity 2 weeks after facial nerve injury. After follow-ups of 1 to 4 years, the outcomes were statistically analysed.
Results: In the minor facial nerve injury group, there was no significant difference in the time needed for initial recovery (Ti, the time needed for significant recovery of the facial nerve function after injury) and final recovery (Tf, the time point after which no further improvement of facial nerve function was obtained) between the two groups (P > 0.05). No adverse effect was found in these cases. In the moderate facial nerve injury group, the Ti and Tf of the treatment group were shorter than those of the control group (P < 0.05). One case had synkinesis. In the patients with severe facial nerve injury, the recovery rate of facial nerve function in the treatment group was higher than that of the control group and the sequelae were less.
Conclusion: Functional training of facial mimic muscles cannot shorten the time of recovery for the patients with minor facial nerve injury but it can speed up the recovery and reduce the undesirable sequelae such as synkinesis and hemifacial spasm for the patients with moderate and severe facial nerve injury.

Evaluation of Dental Root Fracture Using Cone-beam Computed Tomography

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 15:02:14 +0200

Objective: To evaluate the application of cone-beam computed tomography (CBCT) in the detection of dental root fractures and to analyse the demographic profile of these fractures.
Methods: The study group comprised 398 teeth that were examined by CBCT for determining whether they had a root fracture. Patient characteristics were recorded, and the location, fractured roots, fracture types and three-dimensional images of the related skeletal structures were analysed. Two experienced oral radiologists independently analysed each case and reached a consensus, and the diagnosis was graded in one of the following three categories: fracture definitely present (FDP), fracture probably present (FPP) and no visible fracture (NVF).
Results: Among these teeth, 155 (39.0%) were diagnosed as FDP, 14 (3.5%) as FPP and 229 (57.5%) as NVF in the consensus reading. During follow-up, all teeth diagnosed as FDP and 4 of the 14 teeth diagnosed as FPP were intra-operatively demonstrated to be fractured. In FDP cases, 60.0% of the patients were aged from 50 to 69 years. In total, 107 FDP teeth were non-endodontically treated, and the remaining were endodontically treated with (n = 16) or without (n = 32) crown placement. The maxillary and mandibular molars were most frequently affected (81.9%). The fractured roots were mostly palatal (65.7%) in maxillary molars and mesial (84.2%) in mandibular molars. The fractures were characterised as vertical (n = 84), horizontal (n = 34), oblique (n = 5) and complicated (n = 32) fractures.
Conclusion: The application of CBCT is valuable for the diagnosis of root fracture.

A Systematic Review of the Uses of Fluoroscopy in Dentistry

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 11:02:12 +0200

Objective: To determine the quality of the evidence for the uses of fluoroscopy in dentistry.
Methods: A systematic review using Ovid and MEDLINE was conducted to identify papers showing the uses of fluoroscopy in dentistry published between 1953 and September 2009. Human, animal and phantom/skull/mannequin studies on fluoroscopy with regard to its diagnostic value, research performance, and clinical and safety applications in dentistry were included in this analysis. Studies that were not in English, as well as those that employed fluoroscopy in dentistry without the use of image intensification, were excluded. Articles were evaluated, classified and graded by levels of evidence.
Results: Fifty-five out of 139 papers fulfilled the inclusion criteria. Amongst them, 19 were related to diagnosis, 15 to research, 12 to clinical and nine to safety applications. Fluoroscopy has contributed to nine different areas of dentistry. Also, it was used on 895 dental patients, 37 animals and 17 phantoms/skulls/mannequins. Two randomised controlled trials, two cohort studies, two case controls, 48 case reports and one expert opinion were found.
Conclusion: Fluoroscopy with image intensification has been a useful, but not consistently used tool in dentistry for over 50 years. Several lines of evidence have shown fluoroscopy’s diagnostic potential, research use, and clinical and safety applications in dentistry.

Sialendoscopy-based Diagnosis and Treatment of Salivary Ductal Obstructions

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 11:02:11 +0200

Salivary gland ductal obstruction is traditionally treated by sialoadenectomy when conservative measures fail. During the last decade, sialendoscopy has become the preferred approach in the management of salivary ductal obstructions. Sialendoscopy can provide direct, accurate and reliable visualisation of the salivary duct lumen and ductal pathologies, and can eliminate pathologies with miniaturised instrumentation. Now, sialendoscopic surgery is a promising option for patients who can be offered a satisfactory clinical outcome while avoiding sialoadenectomy. The present article briefly outlines sialendoscopy-based diagnosis and treatment of salivary ductal obstructions.

TGF-ß Signalling and Tooth Development

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 11:02:10 +0200

Members of the transforming growth factor-β (TGF-β) superfamily are critical regulators that control cell proliferation, differentiation and apoptosis. TGF-β signalling also regulates the morphogenesis of many developing organs. The development of mouse tooth germ, which is a good model for organogenesis, provides a powerful tool for elucidating the molecular mechanisms that control organogenesis. As ectodermal appendages, the tooth organ arises from complex and progressive interactions between an ectoderm, the oral epithelium and an underlying mesenchyme. Their morphogenesis is regulated by conserved signalling pathways, including TGF-β. In this review, the essential function of the TGF-β superfamily will be discussed in detail, including TGF-β, bone morphogenetic proteins (BMP), activin, etc, during tooth crown patterning and following tooth root development. The review also highlights recent advances in the understanding of Smad-dependent and Smad-independent pathways in regulating tissue-tissue interactions during patterning of tooth crown and root.

Editorial

Quintessenz Verlag Berlin — Wed, 30 Jun 2010 11:02:09 +0200

Conference Report: 10th CMD Symposium in Bremen and 1st Annual Meeting of the CMD-DachverbandKongressbericht: 10. Bremer CMD-Symposium und 1. Jahrestagung des CMD-Dachverbands

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:29 +0200

Journal World/Reviews: Gender differences in craniomandibular dysfunctionZeitschriftenreferat: Geschlechterunterschiede bei kraniomandibulären Dysfunktionen

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:29 +0200

Conference Report: International Bruxism ConferenceKongressbericht: Internationaler Bruxismuskongress

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:28 +0200

Book Review: Recognizing and Treating Functional DisordersBuchbesprechung: Funktionsstörungen erkennen und behandeln

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:27 +0200

Cognitive strategy in the stomatognathic organWahrnehmungsstrategie im stomatognathen Organ

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:26 +0200

The mechanosensors that are located within the periodontal ligament (PDL) are most sensitive to the minimal forces that act upon them when touched without any force1. Accordingly, the moment of occlusal contact is perceived more easily if the patient only touches the occlusal surfaces without putting any load on them. In order to achieve this behavior, patients can be effectively instructed during treatment. They are familiarized with imagining the dental substance as being fragile and not able to take any load, and they are asked to act accordingly. This line of thought only permits a cautious touching of the occlusal surfaces and forbids any masticatory pressure. If the activity of the stomatognathic organ consists in the occlusal surfaces only touching each other, this is not a modification of masticatory activity, but the opposite of masticatory work. Like in other sensorimotor organs, in the stomatognathic organ one has to differentiate between a working strategy, which is supposed to produce an output, and a cognitive strategy, which is supposed to impart a perception. The task of touching the “fragile" tooth surfaces leads to a change of strategy that turns the masticatory organ that does the chewing work into a tactile organ. In restorative dentistry, new occlusal defects can be clearly detected and eliminated by employing a corresponding cognitive strategy. In functional diagnostics, the change of strategy is the basis for a fast and complete reduction of increased muscle tone. As a result, premature contacts can be diagnosed reliably.

Die innerhalb des Parodontalligaments (PDL) liegenden Mechanosensoren sind für die geringen Kräfte am empfindlichsten, die bei einer kraftlosen Berührung einwirken. Dementsprechend wird eine okklusale Kontaktaufnahme leichter erkannt, wenn der Patient Kauflächen nur berührt und nicht belastet. Zu diesem Verhalten können Patienten während der Behandlung wirkungsvoll angeleitet werden. Dazu werden sie mit dem Gedanken vertraut gemacht, sich die Zahnsubstanz als zerbrechlich und nicht belastbar vorzustellen, und dementsprechend zu agieren. Dieser Gedankengang erlaubt nur eine berührende okklusale Kontaktaufnahme und verbietet jeglichen Kaudruck. Eine die Kauflächen nur berührende Tätigkeit des stomatognathen Organs ist nicht eine Modifikation der Kautätigkeit, sondern stellt das Gegenteil der Kauarbeit dar. Wie in anderen sensomotorischen Organen muss auch im stomatognathen Organ zwischen Arbeitsstrategie, die Leistung erzeugen soll, und Wahrnehmungsstrategie, die Erkenntnis vermitteln soll, unterschieden werden. Die Aufgabe, “zerbrechliche" Zahnoberflächen zu berühren, löst einen Strategiewechsel aus, der das arbeitende Kauorgan zum erkennenden Tastorgan macht. In der restaurativen Zahnheilkunde können mit einem wahrnehmungsstrategischen Handeln neue okklusale Fehler sicher erkannt und beseitigt werden. In der Funktionsdiagnostik ist der Strategiewechsel die Grundlage für einen schnellen und vollständigen Abbau eines erhöhten Muskeltonus. In der Folge können Frühkontakte sicher diagnostiziert werden.

Therapeutic communication with CMD patientsTherapeutische Kommunikation mit CMD-Patienten

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:26 +0200

While the first part of this paper outlined the general aspects of communicating with CMD patients, the present article will describe the specific communication processes for the examination and consultation of patients with chronic pain. It will detail how to communicate with patients about their history and findings and will describe a procedure for the psychological consultation of CMD patients. Each individual element of this procedure serves a common purpose: to enable the patient to experience that they are capable of influencing their disorder and to thus motivate them to actively participate in their treatment.

Nachdem im ersten Teil dieses Beitrags die allgemeine Kommunikation mit CMD-Patienten dargestellt wurde, beschreibt der vorliegende Artikel die spezifischen Kommunikationsprozesse während der Untersuchung und Beratung chronischer Schmerzpatienten. Erläutert werden die kommunikative Gestaltung der Anamnese, die Vermittlung der funktionellen Befunde sowie der Ablauf der psychologischen Beratung von CMD-Patienten. Die einzelnen Elemente des gesamten Ablaufs dienen dabei alle dem Ziel, dem Patienten das Erleben der Beeinflussbarkeit seiner Erkrankung zu ermöglichen und ihn so zur aktiven Mitarbeit während der Therapie zu motivieren.

The Saarbrücken treatment protocol for orofacial pain following the principles of evidence-based dentistrySaarbrücker Praxiskonzept orofaziale Schmerzen auf Grundlage der evidenzbasierten Zahnmedizin

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:25 +0200

It is the aim of the present paper to introduce a systematic, practical approach for the state-of-the-art management of patients with orofacial pain in a private office setting. The use of the RDC/TMD (Research Diagnostic Criteria for Temporomandibular Disorders) has proven especially useful for the diagnosis in patients with craniomandibular dysfunctions (CMD). The RDC/TMD is an internationally renowned and validated procedure using checklists that includes other orofacial pain diagnoses to allow for a differential diagnosis. Through prioritizing the treatment options for CMD patients, evidence-based dentistry has become an integral part of practice routines. A correct assessment of the results from scientific studies combined with the practitioner’s own clinical expertise allows a dentist to create a purposeful and efficient treatment strategy within his or her network of therapists and in cooperation with the patient.

Das Ziel des vorliegenden Beitrags besteht darin, ein praxistaugliches Konzept vorzustellen, mit dem in der niedergelassenen Zahnarztpraxis Patienten mit orofazialen Schmerzen zeitgemäß betreut werden können. Als besonders hilfreich erweist sich in der Diagnostik von Patienten mit kraniomandibulären Dysfunktionen (CMD) die Anwendung der RDC/TMD-Kriterien, einem international anerkannten und validierten Verfahren, unter differenzialdiagnostischer Einbeziehung anderer orofazialer Schmerzdiagnosen mittels Checklisten. Durch eine Priorisierung von Therapieoptionen bei der Behandlung von CMDPatienten hat sich die evidenzbasierte Zahnmedizin einen festen Platz in der Praxis erobert. Die richtige Gewichtung von Ergebnissen aus wissenschaftlichen Studien mit der klinischen Expertise des Behandlers ermöglicht dem Zahnarzt – in Abstimmung mit dem Patienten – eine zielführende und effiziente Therapiestrategie innerhalb seines Therapeutennetzwerks.

ENDO / Endodontie Symposium

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:23 +0200

Topographic evaluation of polycaprolactone-based root canal filling materials: a scanning electron microscopic study

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:22 +0200

Objective: The present in vitro study compared the effect of lipase enzyme on the surface topography of Resilon and gutta-percha cones.
Method: Specimens of gutta-percha and Resilon cones were divided into experimental and control groups, one positive and one negative. Experimental groups were immersed in lipase. Positive controls were immersed in phosphate buffer saline, whereas specimens from negative controls were not immersed in any solution. All specimens were incubated at 37˚C for 96 hours and then examined under SEM for surface roughness, and scored by two independent observers.
Results: A statistically significant difference among mean values was seen, with group II (Resilon/ lipase) showing the highest mean value of 2.675 ± 0.355, and group V (gutta-percha/unimmersed) having the lowest mean value of 1.375 ± 0.270.

Non-surgical retreatment: experimental studies on the removal of root filling materials

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:21 +0200

A fundamental step in non-surgical retreatment is the removal of the existing root filling material to permit radicular access. Different root filling materials require different techniques of removal. The endodontic literature is littered with studies exploring the relative merits of one technique of removal over another. In this review, the focus is on the experimental models and techniques employed to investigate the removal of root filling materials during non-surgical retreatment. The correlation and clinical relevance to everyday endodontic practice is also discussed.

Alternative and contemporary management of large periradicular lesions

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:21 +0200

The management of large periradicular lesions has been somewhat limited in contemporary endodontics to non-surgical or surgical treatment, treatment revision in some cases, and immediate extraction in favour of implant prostheses. Within these choices there are both advantages and disadvantages. With the intent to establish removal of the aetiology and elicit a positive osseous, regenerative response, the use of decompression or marsupialisation techniques afford the patient clinician the opportunity to achieve the ultimate goal of tooth retention within a sound and stable environment. This paper will address the many facets, considerations, ramifications and techniques of using this minimally invasive procedure, in addition to addressing new technologies that purport to enhance the kinetics of periradicular tissue healing when larger periradicular lesions are present.

Influence of the final apical diameter on the sealing ability of AH Plus versus RealSeal: an ex-vivo study

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:20 +0200

Aim: To compare the cross-sectional area of sealer plus voids of gutta-percha/AH Plus and Resilon/ RealSeal following root canal preparation with rotary nickel-titanium ProTaper instruments and different apical preparation sizes.
Materials and Methods: Forty-eight extracted maxillary anterior teeth were instrumented with the ProTaper system to apical sizes of 25 (F2), 40 (F4) and 60 (F5 + K-files) (n = 16 each). The teeth were divided into six groups (n = for obturation as follows: group 1, apical preparation size 0.25 mm + gutta-percha/AH Plus sealer; group 2, apical preparation size 0.25 mm + Resilon/ RealSeal; group 3, apical preparation size 0.40 mm + gutta-percha/AH Plus sealer; group 4, apical preparation size 0.40 mm + Resilon/RealSeal; group 5, apical preparation size 0.60 mm + guttapercha/ AH Plus; group 6, apical preparation size 0.60 mm + Resilon/RealSeal. All root canals were filled using the warm vertical compaction technique. Horizontal sections were obtained every 1 mm, up to 3 mm from the apical foramen. Samples were observed by scanning electron microscopy under x200 magnification. Sections were digitally photographed under a stereomicroscope and the images were transferred to a compatible PC for image analysis. Using a computer program, the surface areas of voids were calculated and compared statistically for different preparation sizes and obturation systems at all levels, using the Kruskal-Wallis test with Sidak correction and Mann- Whitney U test (P < 0.05).
Results: Comparisons within each obturation group (gutta-percha/AH Plus and Resilon/RealSeal) showed the presence of voids, but there were no significant differences between the two groups for apical preparation sizes of 25 and 40 (P < 0.05), irrespective of the level of sectioning. The only significant difference was obtained for canals prepared to an apical size 60: canals obturated with Resilon/RealSeal showed significantly more voids than those filled with gutta-percha/AH Plus, especially at the 3-mm level.
Conclusions: Resilon/RealSeal did not achieve better results in terms of sealing ability in the apical third when compared to the conventional obturation materials gutta-percha/AH Plus.

A rare case of multiple taurodont teeth

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:19 +0200

Taurodonts are teeth with enlarged pulp chambers and apical displacement of the bifurcation or trifurcation of roots. The molars and premolars are the teeth that are affected and are more common in the permanent dentition. Taurodontism is usually associated with several syndromes. These teeth have normal coronal structure and can be identified only by radiographs. This condition can be a challenge to an endodontist because of the complex pulp space anatomy. This case report describes a unique case of taurodontism in an otherwise healthy patient – whose existing molars are all taurodonts – and root canal treatment of a taurodont tooth.

Editorial: Retreatment and healing of apical periodontitis

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:18 +0200

Radix paramolaris and entomolaris – report of three cases in an Indian dental school

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:18 +0200

Knowledge of dental anatomy is important for successful root canal treatment. A clinician is required to have insights into the morphology of a tooth, regarding its shape, form and structure, before commencing treatment. This report describes the treatment of two cases of radix entomolaris (one with bilateral occurrence) and one very rare case of radix paramolaris in an Indian dental school.

Oral Health Attitudes and Behaviour as Predisposing Factor for Dental Caries Experience Among Health Professional and Other Professional College Students of India

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:17 +0200

Purpose: The objective of the present study was to determine if there existed any difference between the attitudes and behaviour apart from dental caries status among health professional and other professional college students and to investigate the association of oral health attitudes and behaviour with dental caries.
Materials and Methods: The Hiroshima University-Dental Behaviour Inventory (HU-DBI) questionnaire was used to survey 1824 young student population of Udaipur, India. Dental caries status was evaluated using the World Health Organization caries diagnostic criteria for decayed, missing and filled teeth and surfaces (DMFT and DMFS, respectively).
Results: There was a significant difference (P < 0.05) between the health professional and other professional college students for various components of DMFT and DMFS. Moreover, health professional students reported significantly higher HU-DBI scores (better oral health attitudes and behaviour) than their comparative group. Untreated dental caries played a major contribution to the total DMFT scores in both the groups, with 0.23 and 0.28 mean decayed teeth reported among health professional and other professional students, respectively. Decayed and missing teeth components exhibited a significant negative correlation with HU-DBI scores, whereas a positive correlation existed with the filled teeth component.
Conclusions: A difference existed between the health professional and other professional students with regard to caries experience, oral health attitudes and behaviour. DMF indices and their components were related to most of the oral health attitudes and behaviours. Decayed and missing teeth components were negatively related while filled component was positively related to HU-DBI score.

Influence of Dental Plaque on Human Enamel Erosion: In Situ / Ex Vivo Study

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:16 +0200

Purpose: The objective of the present in situ study was to evaluate the influence of dental plaque on human enamel erosion.
Materials and Methods: Thirteen volunteers wore acrylic palatal devices with four enamel specimens that were prepared from freshly extracted impacted human third permanent molars (4 x 4 mm), randomly selected and distributed into two vertical rows, corresponding to the following groups: GI, erosion of dental plaque-free samples, and GII, erosion of dental plaque-covered samples. For the formation of dental plaque, the specimens were placed 1 mm below the level of the appliance and covered with a plastic mesh to allow the accumulation of dental plaque. The palatal device was continuously worn by the volunteers for 14 consecutive days and then immersed in a soft drink (Coca-Cola, 150 ml) for 5 min, three times a day. Half of the surfaces of specimens were coated with nail varnish for profilometry tests. The study variables included the depth of enamel surface wear (profilometer, vertical ranges in lm) and the percentage of superficial microhardness change (%SMHC). Data were analysed using the t test (P < 0.05).
Results: The %SMHC and depth of enamel surface wear were significantly higher for GI (-87.82% ± 3.66 and 4.70 lm ± 1.65) than for GII (-13.79% ± 4.22 and 0.14 lm ± 0.03).
Conclusions: It was concluded that the dental plaque formed in situ was able to protect the enamel surface against erosion by a cola soft drink, thus reducing the depth of enamel surface wear and the %SMHC.

Recommendations by Dental Staff and Use of Thoothpicks, Dental Floss and Interdental Brushes for Approximal Cleaning in an Adult Swedish Population

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:16 +0200

Purpose: The aim of the present study was to evaluate the recommendations relating to the use of approximal cleaning aids given by dental hygienists and dentists, the self-care practices in a Swedish population and the ability to remove dental plaque.
Materials and Methods: A structured questionnaire was randomly distributed to 500 dental hygienists and 500 dentists and a similar questionnaire was distributed to 1000 randomly selected individuals, divided equally into the following age groups: 15 to 20, 21 to 40, 41 to 60 and > 60 years. A clinical examination evaluating the ability to remove approximal dental plaque was also carried out in a total of 60 regular users of approximal cleaning aids. Plaque was scored before and after cleaning with a toothpick, dental floss or an interdental brush.
Results: The response rate was 82%, 79% and 68% for the three groups. The results reveal that dental hygienists give more detailed information about a majority of the aspects that are related to the use of approximal cleaning aids compared with dentists (P < 0.01 or P < 0.001). The majority of the dental staff give recommendations to children and adolescents firstly to prevent dental caries and to older individuals to improve periodontal health. The use of different approximal cleaning aids on a daily basis varied with respect to age group (2% to 42%); dental floss dominated in the younger age groups and interdental brushes in the two oldest groups. In the clinical study, the largest plaque reduction was produced by the interdental brush (83%), followed by toothpicks (74%) and dental floss (73%).
Conclusions: The present study indicated the importance of individual recommendations related to the use of approximal cleaning aids.

Relationship Between Dietary Patterns and Dental Caries in Sri Lankan Adolescents

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:15 +0200

Purpose: The aim of the present study was to assess the relationship between dental caries and dietary patterns in Sri Lankan adolescents.
Materials and Methods: The sample consisted of 1218, 15-year-olds who were selected from 48 schools in the Colombo district of Sri Lanka using a stratified cluster sampling technique. Data were collected by distributing questionnaires among both adolescents and their parents and by conducting an oral examination of all adolescents. A validated 13 foods/food groups food frequency questionnaire was used to obtain dietary information.
Results: Factor analysis extracted three dietary patterns from the 13 foods/food groups, and these patterns accounted for 41.44% of variation in the dietary intake. They were labelled as sweet, healthy and affluent dietary patterns. From the multiple logistic regression analysis, the sweet dietary pattern, household income and oral hygiene status emerged as significant predictors of dental caries.
Conclusions: It was concluded that dietary pattern labelled as sweet emerged as a significant predictor of dental caries.

Erosive Potential of Calcium-Modified Acidic Candies in Irradiated Dry Mouth Patients

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:15 +0200

Purpose: Patients who have received irradiation therapy on the head and neck area are known to suffer from reduced saliva flow and may therefore use acidic candies to relieve symptoms of dry mouth. However, such acidic candies have erosive potential even among healthy individuals. Therefore, the aim of the present study was to determine if calciummodified acidic candies have reduced erosive potential in irradiated cancer patients.
Materials and Methods: Nineteen cancer patients (26 to 70 years) ipsilaterally irradiated on the head and neck area sucked control and calcium-modified acidic candies, while their whole saliva was collected into a closed system. The erosive potential of both candies was evaluated from saliva degree of saturation with respect to hydroxyapatite and by dissolution of hydroxyapatite (HAp) directly in candy-stimulated saliva. The results were compared to normative data that were previously obtained on 20 healthy test persons (21 to 29 years).
Results: No significant difference was obtained in the saliva flow rates between control and calcium-modified candy. However, the saliva became significantly less undersaturated with respect to HAp when sucking calcium-modified compared to control candy (P < 0.001) and more undersaturated for both candies in ipsilaterally irradiated cancer patients compared to normative data (P < 0.001). HAp dissolution was found to be significantly lower in patients sucking the modified candy compared to the control candy (P < 0.01) and, surprisingly, slightly lower in patients compared to normative data.
Conclusions: Modified acidic candy with calcium has reduced erosive potential in patients irradiated on the head and neck area and could therefore be used as a favourable stimulant for relief of dry mouth.

Is Titanium Tetrafluoride (TiF4) Effective to Prevent Carious and Erosive Lesions? A Review of the Literature

Quintessenz Verlag Berlin — Fri, 25 Jun 2010 15:02:14 +0200

The present review summarises the effects of titanium tetrafluoride (TiF4) on the development and progression of carious and erosive lesions. The mode of action of TiF4 is due to the formation of an acid-stable surface layer, which provides mechanical protection to the surface, and to an increased fluoride uptake, which might chemically reduce demineralisation of dental hard tissues. Most in vitro studies showed that TiF4 is effective in reducing the formation of carious and erosive enamel and dentine lesions. Thereby, TiF4 was equally or more effective than sodium fluoride (NaF), amine fluoride (AmF) or stannous fluoride (SnF2). While clinical data confirm the caries-preventive effect, clinical trials analysing the anti-erosive effect of TiF4 are lacking. Few data available from in situ studies revealed conflicting results by showing either no effect or a beneficial effect of TiF4 on enamel erosion. Even though research focused on TiF4, there is also evidence to show that other metal fluorides, such as zirconium and hafnium tetrafluorides, affect enamel and dentine demineralisation.
Conclusion: The potential of TiF4 to prevent acid demineralisation requires further research to confirm the promising in vitro results obtained by in situ studies and clinical trials.

Quintessenz Verlag Berlin @ zahnigroups

2010 Guidelines of the Academy of Osseointegration for the Provision of Dental Implants and Associated Patient Care

Retrospective Study of the Long-Term Survival of 980 Implants Placed in a Periodontal Practice

Five-Year Follow-up of Wide-Diameter Implants Placed in Fresh Molar Extraction Sockets in the Mandible: Immediate Versus Delayed Loading

One-Step Approach for Implant Placement and Subantral Bone Regeneration Using Bovine Hydroxyapatite: A 2- to 6-Year Follow-up Study

Removable Implant-Prosthodontic Rehabilitation of the Edentulous Mandible: Five-Year Results of Different Prosthetic Anchorage Concepts

Applications of Surgical Navigational Systems for Craniofacial Bone-Anchored Implant Placement

Peri-Implant Bone Level Around Implants with Platform-Switched Abutments

Nonsurgical Treatment of Retrograde Peri-implantitis: A Case Report

Fabrication of a Surgical Template for Orbital Implant Placement: A Case Report

Reconstruction of Severely Resorbed Maxilla with Biodegradable Polylactide Screws: Case Series

Maximum Use of the Anterior Maxillary Buttress in Severe Maxillary Atrophy with Tilted, Palatally Positioned Implants: A Preliminary Study

Rehabilitation of the Nose Using CAD/CAM and Rapid Prototyping Technology After Ablative Surgery of Squamous Cell Carcinoma: A Pilot Clinical Report

Vertical Ridge Augmentation with Autogenous Bone Grafts 3 Years After Loading: Resorbable Barriers Versus Titanium-Reinforced Barriers. A Randomized Controlled Clinical Trial

Patient Satisfaction and Oral Health-Related Quality of Life Outcomes of Implant Overdentures and Fixed Complete Dentures

Immediate Loading of Two Freestanding Implants Retaining a Mandibular Overdenture: 1-Year Pilot Prospective Study

The Effect of Miniscrew Taper Morphology on Insertion and Removal Torque in Dogs

Comparison of Impression Techniques and Materials for an Implant-Supported Prosthesis

Bone Stress Analysis of Various Angulations of Mesiodistal Implants with Splinted Crowns in the Posterior Mandible: A Three-Dimensional Finite Element Study

Immediate Loading as a Vehicle for Interdisciplinary Training in Implant Placement and Restoration

Impact of Abutment Rotation and Angulation on Marginal Fit: Theoretical Considerations

Critical Bending Moment of Four Implant-Abutment Interface Designs

The Effect of Increased Crown-to-Implant Ratio on Single-Tooth Locking-Taper Implants

Analysis of the Attachment and Differentiation of Three-Dimensional Rotary Wall Vessel Cultured Human Preosteoblasts on Dental Implant Surfaces

Accuracy of Impression Techniques for an Implant-Supported Prosthesis

Effects of Cortical Bone Thickness and Implant Length on Bone Strain and Interfacial Micromotion in an Immediately Loaded Implant

Three-Dimensional Culture of Mandibular Human Osteoblasts on a Novel Albumin Scaffold: Growth, Proliferation, and Differentiation Potential In Vitro

Characterization of the Normal Bacterial Flora in Peri-implant Sulci of Partially and Completely Edentulous Patients

Study of an Experimental Microthreaded Scalloped Implant Design: Proximal Bone Healing at Different Interimplant Distances in a Canine Model

In Vivo Comparison of Bone Formation on Titanium Implant Surfaces Coated with Biomimetically Deposited Calcium Phosphate or Electrochemically Deposited Hydroxyapatite

Thematic Abstract Review: CBCT AccuracyAn Update

Editorial: Rules and Regulations

Comparison of Two Piezoelectric Cutting Inserts for Lateral Bony Window Osteotomy: A Retrospective Study of 127 Consecutive Sites

A Prospective Randomized Clinical Study of Changes in Soft Tissue Position Following Immediate and Delayed Implant Placement

Bone Changes Around Early Loaded Chemically Modified Sandblasted and Acid-Etched Surfaced Implants With and Without a Machined Collar: A Radiographic and Resonance Frequency Analysis in the Canine Mandible

Determination of Primary Stability: A Comparison of the Surgeons Perception and Objective Measurements

Influence of Microgap Location and Configuration on Peri-implant Bone Morphology in Nonsubmerged Implants: An Experimental Study in Dogs

Allogeneic Bone Onlay Grafts for Alveolar Ridge Augmentation: A Systematic Review

Parameters of Implant Stability Measurements Based on Resonance Frequency and Damping Capacity: A Comparative Finite Element Analysis

Review of Dental Implant Rat Research Models Simulating Osteoporosis or Diabetes

Assessing the Fit of Implant Fixed Prostheses: A Critical Review

Multichannel Computed Tomography Versus Cone-Beam Computed Tomography: Linear Accuracy of In Vitro Measurements of the Maxilla for Implant Placement

Comparison of the Accuracy of Invasive and Noninvasive Registration Methods for Image-Guided Oral Implant Surgery

Morphologic Classification and Stress Analysis of the Mandibular Bone in the Premolar Region for Implant Placement

The Effects of Different Loading Times on the Bone Response Around Dental Implants: A Histomorphometric Study in Dogs

Microgap Between Zirconia Abutments and Titanium Implants

Evaluation of Multiple Implant-Bone Parameters on Stress Characteristics in the Mandible Under Traumatic Loading Conditions

Thematic Abstract: Status Update: “Short Implants” Outcomes

Editorial: When Silver Touches Titanium

Paraneoplastic pemphigus characterized by polymorphic oral mucosal manifestations – Report of two cases

A long-term laboratory test on staining susceptibility of esthetic composite resin materials

In vitro study of the correlation between the simulated clinical and radiographic examination of microgaps at the implant-abutment interface

The impact of nonautogenous bone graft on orthodontic treatment

Audiovisual video eyeglass distraction during dental treatment in children

Follicular lymphoma in the palate with clinical appearance similar to salivary gland tumors

Immediate definitive rehabilitation of the edentulous patient using an intraorally welded titanium framework: A 3-year prospective study

Bismuth subgallate as a topical hemostatic agent at palatal donor sites

A comparative study of bone densitometry during osseointegration: Piezoelectric surgery versus rotary protocols

Prospective study of zirconia-based restorations: 3-year clinical results

Dental caries in an impacted mandibular second molar: Using cone beam computed tomography to explain inconsistent clinical and radiographic findings

Guest Editorial: Diagnosis and Treatment of Temporomandibular Disorders: Emergence of a New “Standard of Care”

A retrospective study of edentulous patients rehabilitated according to the ‘all-on-four’ or the ‘all-on-six’ immediate function concept using flapless computer-guided implant surgery

Markers of systemic inflammation in periodontal patients: chronic versus aggressive periodontitis. An explorative cross-sectional study

Effectiveness of prophylactic antibiotics at placement of dental implants: a pragmatic multicentre placebo-controlled randomised clinical trial

The influence of platelet-rich plasma on the healing of extraction sockets: an explorative randomised clinical trial

Immediate occlusal versus non-occlusal loading of single zirconia implants. A multicentre pragmatic randomised clinical trial

Does antibiotic prophylaxis at implant placement decrease early implant failures? A Cochrane systematic review

Editorial: EJOI is on PubMed!

Hyperplastic Dental Follicle – Review of Literature and Report of Two Cases in One Family

One-stage Operation for Norma-induced Bilateral Ankylosis Accompanied with Mouth Verrucous Carcinoma – a Case Report and Review of Literature

Multiple Retentive Means for Prosthetic Restoration of a Large Facial Defect – a Case Report

Progress of Oral Sequelae During Head-Neck Radiotherapy

Prevalence of Traumatic Dental Injuries to Permanent Incisors Among 12-year-old School Children in Davangere, South India

Involvement of Notch Signalling Pathway in Senescence of Human Dental Pulp Cells

Efficacy of Functional Training of the Facial Muscles for Treatment of Incomplete Peripheral Facial Nerve Injury

Evaluation of Dental Root Fracture Using Cone-beam Computed Tomography

A Systematic Review of the Uses of Fluoroscopy in Dentistry

Sialendoscopy-based Diagnosis and Treatment of Salivary Ductal Obstructions

TGF-ß Signalling and Tooth Development

Editorial

Thematic Abstract Review: CBCT AccuracyAn Update

Determination of Primary Stability: A Comparison of the Surgeons Perception and Objective Measurements