Ten-year survival rates of teeth adjacent to treated and untreated posterior bounded edentulous spaces

Statement of problem. Failure to replace a single missing posterior tooth m ay lead to a variety of dental problems, which may ultimately result in too th loss. However, little is known about the fate of the adjacent teeth ifa missing posterior tooth is not replaced. Purpose. This retrospective study evaluated the survival of teeth adjacent to treated and untreated posterior bounded edentulous spaces. Material and methods. Data were obtained from electronic treatment records from the Kaiser Permanente Dental Care Program, Portland, Ore. A final samp le of 317 patients who met the study inclusion criteria was identified. Eac h bounded edentulous space was placed in 1 of 3 treatment categories: untre ated, restored with a fixed partial denture, or restored with a removable p artial denture. Subsequent treatment and the status of the teeth adjacent t o the bounded edentulous space were followed through December 1999. Ten-yea r Kaplan-Meier survival estimates were generated for each treatment group, and differences in survival were evaluated with the log-rank chi-square tes t (alpha=.05). Results. There was a significant difference in survival among the 3 treatme nt categories (P=.005). Spaces restored with a fixed partial denture had lo nger 10-year survival estimates (92%) than those that remained untreated (8 1%). Spaces restored with a removable partial denture had the poorest 10-ye ar survival rate (56%). Conclusion. Under the conditions and selection bias associated with this re trospective study, the survival of teeth adjacent to a single posterior ede ntulous space was negatively associated with removable partial denture plac ement compared with no treatment or the use of a fixed partial denture.