The up-to-11-year survival and success of implants and abutment teeth under solely implant-supported and combined tooth-implant-supported double crown-retained removable dentures.

Abstract

This retrospective analysis was designed to compare the survival and success of dental implants in solely implant-supported, double crown-retained removable dentures (DCRDs) and combined tooth-implant-supported DCRDs, due to a lack of data on the latter. From 2002, patients were consecutively admitted for treatment at the Department of Prosthodontics, University of Heidelberg. Surgical and prosthodontic treatment and scheduled and unscheduled visits were recorded on standardized documentation forms. Kaplan-Meier analysis was used to estimate success (survival without major complications). Cox regression was applied to assess risk factors. From this clinical study, 139 DCRDs on 412 implants and 239 teeth met the inclusion criteria. Fifty-three dentures were implant-supported (213 implants). Eighty-six were supported by teeth and implants. The DCRDs were placed in 126 patients. After an observation period of up to 11.2years (median: 4.2years), total implant survival was 99.5% for tooth-implant-supported DCRDs and 93.4% for implant-supported ones. The estimated cumulative success was 97.2% (standard error/SE±1.2%) and 85.9% (SE±2.4%) at five years, respectively. Complications included implant or tooth loss, peri-implantitis, apical periodontitis and tooth fracture. In terms of abutments, results from multiple Cox regression revealed lower failure rates in tooth-implant-supported dentures (p=.04). No other risk factors were identified. Within the limitations of this study, survival and success are high for both treatment options. Combining teeth and implants in one DCRD might have a positive effect on the prognosis of the implant and the survival of remaining teeth.