Mark S. Scurria

Meta-analysis of fixed partial denture survival: Prostheses and abutments

STATEMENT OF PROBLEM Few estimates of the probability of various outcomes associated with replacement of missing teeth with fixed partial dentures have been reported. Existing longitudinal studies have reported widely disparate results for the survival of fixed partial dentures, but these studies have used different definitions of failure and varying periods of follow-up. PURPOSE This study used meta-analysis to formulate annual probability estimates for three categories of fixed partial denture or abutment survival. METHODS A systematic review of the English language literature since 1960 identified eight studies that met the preset inclusion criteria. Estimated annual survival proportions were back-calculated based on the Kaplan-Meier model and these proportions were combined through a fixed effects model meta-analysis. The probabilities and corresponding 95% confidence intervals at 5, 10, and 15 years for the three categories of survival are reported. RESULTS For the aggregate population represented by the limited longitudinal studies available, this meta-analysis indicated that less than 15% of fixed partial dentures were removed or in need of replacement at 10 years; whereas, nearly one third were removed or in need of replacement at 15 years. Less than 5% of abutments were removed at 10 years.

Surface roughness of two polished ceramic materials

Conventional and CAD-CAM ceramic restorations often require adjustments that result in a need to reduce surface roughness. Surface roughness resulting from five polishing systems on two ceramics was assessed. Disks of Ceramco II and Dicor MGC ceramic blocks were polished with five combinations of 45, 25, and 10 microns diamonds; a 30-fluted carbide; three silicon carbide-impregnated rubber points; 4 and 1 micron diamond gels; and an aluminum oxide point and two aluminum oxide pastes. Five profilometer average roughness measurements (Ra) were taken of five replications of each step in each sequence. Controls were autoglazed Ceramco II and Dicor MGC ceramic specimens milled with a Cerec diamond wheel. Feldspathic porcelain could be polished smoother than glazed. Dicor ceramic could be polished smoother than Ceramco II ceramic. Finishing diamond points followed by diamond gels produced the smoothest surface. A 30-fluted carbide did not improve smoothness as used. The aluminum oxide point followed by aluminum oxide pastes was equivalent to finishing diamonds and gels for Dicor ceramic.

A conceptual framework for understanding outcomes of oral implant therapy

The use of implants has expanded so rapidly that its effectiveness for many clinical situations has not been firmly established. Dentists are responsible for making appropriate therapeutic recommendations for the management of partial and complete edentulism. These decisions require an understanding of the consequences or outcome of treatment approaches. Outcome measures to evaluate the benefits of alternative therapies include longevity as well as physiologic, psychologic, and economic impacts. Future research should include outcome measures beyond implant prosthesis survival to more fully assess the practical impact of dental implants on the patients oral health and to determine the most cost-effective approaches for managing completely and partially edentulous patients.