Randomized, prospective, clinical evaluation of prosthodontic modalities for mandibular implant overdenture treatment.

STATEMENT OF PROBLEM: Mandibular implant overdentures provide improved treatment outcome than conventional denture therapy, but there is controversy as to which overdenture treatment is the best choice. PURPOSE: This study evaluated 3 different mandibular implant overdenture treatments with respect to prosthesis retention and stability, tissue response, patient satisfaction and preference, and complications to determine treatment outcomes. MATERIAL AND METHODS: In a prospective, randomized clinical trial, using a crossover design, 30 subjects (mean age, 58.9; 63% male) received 4 implants in the anterior mandible. For each subject, 3 different overdenture attachment types were fabricated and/or fitted to the implants. These included a 4-implant bar attachment fitted to all 4 implants, a 2-implant bar attachment, and 2 independent ball attachments. Subjects were randomly assigned to 1 of 6 possible treatment sequences and received all 3 attachment types each for approximately 1 year. Data were collected at baseline, and at 6 and 12 months for treatment types. Denture retention and stability and parameters of soft tissue response were recorded. Complications were documented and questionnaires were used to identify subject masticatory ability, denture complaints, and preferences. Data were analyzed to determine statistical equivalence among the 3 different treatments using the Schuirmann's two one-sided test (TOST) procedure, and the Wilcoxon-Mann-Whitney TOST procedure (α=.05). RESULTS: Force gauge prosthesis retention measurements showed that the 3 treatment types were not statistically equivalent, with the 4-implant bar demonstrating the greatest retention. Criterion-based retention scores were statistically equivalent for all treatments. Both the force gauge and criterion-based prosthesis stability measurements were statistically equivalent among all 3 treatment types. Analysis of all other multiple criterion-based scoring systems indicated the majority of these variables demonstrated equivalence. Where equivalence was not identified, the most favorable responses were typically found with the O-ring treatment, and the least favorable with the 4-implant bar treatment. From the small percentage of treatment visits demonstrating minor complications, no single treatment presented with greater complications than the others. For the treatment preference among subjects, 52% selected the independent ball attachment, 32% the 4-implant bar, and 16% the 2-implant bar (P=.10). CONCLUSIONS: The 2-implant independent treatment used in this study provided equivalent or more favorable treatment outcomes for most measured parameters relative to the more complex and costly 2- and 4-implant bar attachments. The 4-implant bar treatment provided greater prosthesis retention than the other treatment types in this study, but after experience with all systems, subjects were more satisfied with and preferred the independent implant treatment.

Survey of prosthodontic service provided by general dentists in Virginia.

STATEMENT OF PROBLEM: Activities in prosthodontic treatment may be changing due to prevalence of disease and new treatment options. Studies cite conflicting evidence in regard to prosthodontic services, particularly removable prosthodontics. PURPOSE: This project was designed to describe the amount of prosthodontic services provided by general dentists in Virginia. Results may enhance understanding practice patterns in Virginia and regions with similar demographics. MATERIAL AND METHODS: Licensed Virginia dentists (n=600) were randomly selected from the Virginia Department of Health Professions website. Each individual was mailed a survey of questions about his or her demographics and practice activities with regard to prosthodontics. RESULTS: Of the 333 respondents, 195 provide prosthodontic treatment and function as general dentists. On average, they spend 25% of their practice time providing prosthodontic services (17% fixed and 8% removable). They provide at least 1 complete denture for a mean total of 24.3 patients per year, at least 1 removable partial denture for a mean total of 28.7 patients per year, at least 1 fixed partial denture for a mean total of 23.0 patients per year, at least 1 implant-supported crown for a mean total of 12.3 patients per year, and at least 1 implant-supported fixed partial denture for mean total of 3.3 patients per year. Data were analyzed using descriptive statistics. Data for total population and median income were analyzed with the Wilcoxon signed rank test. CONCLUSION: Virginia dentists continue to provide considerable numbers of fixed prosthodontic restorations, removable partial dentures, and complete dentures, while providing a growing number of implant-supported restorations.

Survival analysis of complete veneer crowns vs. multisurface restorations: a dental school patient population.

The purpose of this study was to compare the longevity of crowns versus large multisurface restorations in posterior teeth. The investigation used the treatment database at Virginia Commonwealth University School of Dentistry. The inclusion criteria for the final data set used for analysis were: only one restored tooth per patient, premolars with three or more restored surfaces, molars with four or more restored surfaces, molars and premolars restored with complete veneer metal crowns, or crowns veneered with metal and porcelain. The Kaplan-Meier approach was used to visualize the survival curves, and the Cox proportional hazards model was used for analysis of predictor variables. The investigation indicates crowns survive longer than large restorations and premolar restorations survive longer than molar restorations. The median survival for crowns exceeded 16.6 years, with the median survival of premolar restorations being 4.4 years and molar restorations 1.3 years. An interaction between age and treatment was discovered, with overall survival decreasing as patient age increases. The doctor supervising the treatment also affected survival with treatment supervised by specialists lasting longer than treatment supervised by nonspecialists.