The International Journal of Prosthodontics, 02/2013

Purpose: This systematic review aimed to report and explore the survival of dental veneers constructed from non-feldspathic porcelain over 5 and 10 years. Materials and Methods: A total of 4,294 articles were identified through a systematic search involving all databases in the Cochrane Library, MEDLINE (OVID), EMBASE, Web of Knowledge, specific journals (hand-search), conference proceedings, clinical trials registers, and collegiate contacts. Articles, abstracts, and gray literature were sought by two independent researchers. There were no language limitations. One hundred sixteen studies were identified for full-text assessment, with 10 included in the analysis (5 qualitative, 5 quantitative). Study characteristics and survival (Kaplan-Meier estimated cumulative survival and 95% confidence interval [CI]) were extracted or recalculated. A failed veneer was one which required an intervention that disrupted the original marginal integrity, had been partially or completely lost, or had lost retention more than twice. A meta-analysis and sensitivity analysis of Empress veneers was completed, with an assessment of statistical heterogeneity and publication bias. Clinical heterogeneity was explored for results of all veneering materials from included studies. Results: Within the 10 studies, veneers were fabricated with IPS Empress, IPS Empress 2, Cerinate, and Cerec computer-aided design/computer-assisted manufacture (CAD/ CAM) materials VITA Mark I, VITA Mark II, Ivoclar ProCad. The meta-analysis showed the pooled estimate for Empress veneers to be 92.4% (95% CI: 89.8% to 95.0%) for 5-year survival and 66% to 94% (95% CI: 55% to 99%) for 10 years. Data regarding other non-feldspathic porcelain materials were lacking, with only a single study each reporting outcomes for Empress 2, Cerinate, and various Cerec porcelains over 5 years. The sensitivity analysis showed data from one study had an influencing and stabilizing effect on the 5-year pooled estimate. Conclusion: The long-term outcome (> 5 years) of non-feldspathic porcelain veneers is sparsely reported in the literature. This systematic review indicates that the 5-year cumulative estimated survival for etchable non-feldspathic porcelain veneers is over 90%. Outcomes may prove clinically acceptable with time, but evidence remains lacking and the use of these materials for veneers remains experimental.

This report presents a case history of intractable facial pain following the placement of a posterior mandibular implant. The pain was resistant to all medical management, but a cone beam computed tomography (CBCT) scan showed that the implant impinged on an unusual accessory inferior alveolar nerve. The decision to remove the implant led to significant pain reduction. This clinical example underscores the need for scrupulous imaging prior to implant placement.

Purpose: This study identifies clinical factors that predict multiple tooth loss in a socioculturally diverse population of older adults. Materials and Methods: A total of 193 participants from English-, Chinese-, or Punjabi-speaking communities in Vancouver, British Columbia, with low incomes and irregular use of dental services were followed for 5 years as part of a clinical trial of a 0.12% chlorhexidine mouthrinse. The participants were interviewed and examined clinically, including panoramic radiographs, at baseline and annually for 5 years. Binary logistic regression was used to test the hypothesis that there was no difference between incidence of multiple (>= 3) tooth loss in older people with various biologic, behavioral, prosthodontic, and cultural variables over 5 years. Results: Multiple tooth loss, which was distributed similarly among the groups in the trial, occurred in 39 (20%) participants over 5 years. The use of removable prostheses was the best predictor of loss, followed by the number of carious surfaces and number of sites with gingival attachment loss > 6 mm. The pattern of prediction was consistent across the three linguocultural groups. Conclusion: The use of removable dentures was the dominant predictor of multiple tooth loss in the three communities, but that tooth loss was not significantly associated with the cultural heritage of the participants.

The purpose of this clinical study was to compare peri-implant crestal bone levels between misfitting (overhanging/open margin) cement-retained implant single crowns (SCs) vs accurately fitted implant SCs. Seventeen subjects were divided into two groups: test group (misfitting crowns, n = 10) and control group (accurately fitted crowns, n = 7). Crestal bone level changes were assessed using digital software. The average differences in mean bone loss within and between the two groups were statistically significant. Cement-retained implant SCs with marginal misfit resulted in more crestal bone loss than accurately fitted crowns after a mean of 3 years in function.

Purpose: This study aimed to compare the agreement of clinical examination and magnetic resonance imaging (MRI) results before and after the treatment of nonreduction temporomandibular joint (TMJ) disc displacement. Materials and Methods: The study group consisted of 22 patients, each with anterior disc displacement without reduction in at least one TMJ. Diagnosis was performed clinically and with MRI prior to treatment. All patients received the same treatment protocol, consisting of occlusal appliance therapy and exercise for a period of 24 weeks. By the end of treatment, clinical and imaging examinations were repeated and the results subjected to statistical analysis. Results: Before treatment, MRI and clinical examinations matched in 35 of 44 joints (79.5%). On the basis of the kappa index, the agreement between clinical and imaging examinations was moderate (mean kappa index = 0.59, P = .0001). After treatment, these examinations matched in only 16 of 44 cases (36%) and the agreement was poor. Conclusion: Clinical criteria do not necessarily correlate with MRI findings in the postoperative period in patients treated for TMJ anterior disc displacement.

The purpose of this in vivo study was to evaluate the biomechanical effects of splinting of implant-supported superstructures using piezoelectric transducers to measure the three-dimensional forces exerted on implants supporting fixed superstructures. Measuring devices were set into the implant fixtures at the mandibular right second premolar and first molar. During clenching, force magnitudes were allocated more evenly to the two implants if they were splinted compared with the unsplinted control implants. However, this equalization of load distribution was not apparent during wax biting. Splinting of implantsupported fixed superstructures affects the force exerted on implants, especially during clenching.

Purpose: This retrospective clinical study aimed to evaluate the long-term outcomes of clasp-retained, metal-framework removable partial dentures (RPDs) and their clasped teeth, the influencing factors on survival, and the type and number of repairs needed during the observation period. Materials and Methods: The study is based on a convenience sample of 52 patients who received 65 RPDs with a total of 207 clasped teeth. The mean observation period was 3.11 ± 0.29 years (maximum: 10 years). Patient gender, prosthesis location (maxilla/mandible), number and distribution (Kennedy class) of abutment teeth, and impact of a continuous follow-up program on a favorable outcome probability were analyzed. Statistical analysis was performed using the Kaplan-Meier method (P .05) in combination with Cox regression analysis. Results: During the observation period, 9.2% of the RPDs ceased to function and 5.8% of the abutment teeth were extracted. Mean RPD survival time was 8.07 ± 0.66 years, with a positive outcome probability of 90% after 5 years. Prosthesis location was the only parameter that significantly (P .05) impacted this probability. Conclusion: Overall, the high survival probability and low extraction rate of the abutment teeth reported in this study indicate that RPDs designed according to hygienic pronciples are clinically successful.

Purpose: This study aimed to present the up to 25-year clinical performance and survival of 2,340 high gold-based metal-ceramic single crowns placed in a specialist prosthodontic practice. Materials and Methods: All crowns provided to 670 patients between 1984 and 2008 were sequentially recruited. Each crown/tooth combination was given a prognostic evaluation at cementation. Patients were recalled in 2008 and 2009 for examination, and patient records were scrutinized for any retreatment. Estimated cumulative survival, standard error, and differences in survival between groups were calculated using the Kaplan-Meier method, Greenwood formula, and log-rank test, respectively. Crown status (six-field classification) was reported within 5-year groupings and for 7, 10, and 12 years. Results: The up to 10-year and 25-year estimated survival rates of the 2,211 favorably rated crowns were 97.08% ± 0.45% and 85.40% ± 2.19%, respectively. The up to 12-year survival for crowns in the postimplant era was 94.4% ± 2.78%. No significant differences related to sex, tooth type, or tooth position were demonstrated. Nonvital teeth had lower overall survival rates than vital teeth, but not in crowns placed in the postimplant era. Actual 10-year outcomes closely matched the estimated 10-year survival. Biologic factors accounted for 101 of the 133 failures, while mechanical factors accounted for 8 failures and patient concerns accounted for 24 failures. Porcelain fracture requiring replacement occurred in 4 crowns. Conclusions: The clinical performance of the crowns was excellent. Biologic factors accounted for the majority of failures. Material stability was excellent. Patient complaints of unacceptable esthetics resulted in 22 crowns being replaced after a mean clinical service time of 14 years.

The purpose of this investigation was to measure the accuracy of digital impressions (DIs) compared to conventional impressions (CIs). Using the iTero system, a master cast was scanned to produce stereolithography dies. As a control group, silicone impressions were taken and poured using stone. The resulting stereolithography and stone dies were scanned and overlayed on the scanned reference image of the master cast. The mean (± standard deviation) dimensional difference to the master cast was 23.9 (± 17.6) µm for DIs and 17.6 (± 45.6) µm for CIs. The results indicate that DIs also provides enough accuracy for clinical application.

Purpose: The clinical performance of three- and four-unit fixed partial dentures (FPDs) with frameworks made of yttria partially stabilized zirconia was determined after a mean observational period of 84 months. Materials and Methods: Seventy-five patients were treated with 99 posterior FPDs. Fifty-one specimens were veneered with an experimental ceramic suitable for titanium and zirconia frameworks; 48 restorations were veneered with a commercially available low-fusing ceramic optimized for zirconia frameworks. All restorations were luted with zinc-phosphate cement. Statistical analysis was performed according to Kaplan-Meier; potential risk factors were analyzed using the Cox regression analysis. Results: Nineteen restorations failed completely: 12 due to technical complications, 6 due to biologic complications, and 1 for unknown reasons. The overall survival rate after 84 months was 83.4%. Thirty-two events required clinical intervention for restoration maintenance, resulting in a time-dependent success rate of 57.9% after 84 months. Nineteen dropouts occurred during the follow-up time. None of the evaluated factors showed an association with survival or success of the restorations. Conclusions: After a mean observational period of 7 years, the survival and success rates of zirconia-based posterior FPDs were inferior to those published for metalceramic FPDs. The majority of failures were caused by technical complications (material fractures). The main reasons for clinical intervention to maintain function were fractures of the veneering ceramic and decementations.

The placement of individual identification on a prosthesis is very important for forensic dentistry and traceability. This article describes the unique naming/labeling of dentures with information for individual identification using a method in which information is invisible under natural light but visible under ultraviolet light-emitting diode/black light exposure. The use of laser beam machining with this method will enable the recording of a large amount of information.

Purpose: The aim of this prospective study was to evaluate the clinical efficacy and long-term survival rate of three-unit fixed partial dentures (FPDs) made from lithium disilicate-based core ceramic. Materials and Methods: Twenty-one threeunit FPDs were placed in 19 patients to replace single lost teeth in the esthetic area, following a study protocol that took clinical, esthetic, and radiologic aspects into consideration. Each case was reviewed at 1 week following placement, at 6 months, and then annually for 10 years. Statistical analysis was performed using Kaplan- Meier survival analysis. Results: Out of the 19 patients, 14.3% presented reversible postoperative sensitivity. Recession was observed in 24% of dental posts, and 7.1% presented marginal discoloration. Treatment did not increase either Bleeding or Plaque Index scores at prepared teeth; secondary caries did not appear either. The restorations' survival rate at the 10-year follow-up was 71.4%; six FPDs had fractured and one debonded. Conclusions: Fracture failure rate was 28.6% after 10 years; a high percentage corresponded to connector fractures and occurred during the first 5 years. Lithium disilicate glass-ceramic FPDs present a higher risk of fracture than standard therapies (metal-ceramic) or other more recently developed ceramic materials. The prognosis for survival improves for Class I occlusion and nonparafunctional patients.

Purpose: This case series study evaluated the clinical outcomes of cantilevered veneerretained fixed partial dentures (VRFPDs) fabricated with IPS e.max Press for single-tooth replacement in the anterior arch. Materials and Methods: A total of 35 patients were treated with VRFPDs, including 17 cases in the maxilla and 18 in the mandible. The patients were evaluated at baseline and annually from October 2005 to July 2011 for the integrity of the VRFPDs, proximal contacts, occulsal relationships, pulp vitality, and tooth mobility. The degree of satisfaction was indicated with a visual analog scale. Results: During a mean observation time of 46.57 months, 35 VRFPDs on vital abutment teeth did not exhibit postoperative sensitivity or secondary caries. No fractures or chipping of the restorations occurred within the course of the evaluation. No patient complained of food impaction. One cantilevered pontic needed adjustment on the incisal edge due to premature contacts after the 3-year recall examination. Conclusion: Cantilevered IPS e.max Press VRFPDs should be considered a minimally invasive, single-tooth restorative strategy in the anterior or first premolar area. Longer observation periods are necessary before this type of restorative design can be recommended as a general conservative procedure.