Retrospective study of treatment outcomes with implant-retained extraoral prostheses: survival rates and prosthetic complications.

STATEMENT OF PROBLEM: Implant-retained extraoral prostheses are an acceptable solution for patients with facial defects. However, these prostheses have a limited service life. Little has been reported on survival periods of implant-retained extraoral prostheses and prosthetic complications of this treatment modality.

PURPOSE: The purpose of this study was to estimate the survival rates of implant-retained extraoral prostheses and to analyze the frequency of prosthetic complications.

MATERIAL AND METHODS: Seventy patients were treated with implant-retained extraoral prostheses. Each patient was examined with respect to the prosthesis appearance and abutment and attachment component complications at 6-month intervals over a period of 10 to 46 months. The Kaplan-Meier survival estimation method was used for the first and subsequent prostheses. The reasons for remaking prostheses were recorded. Complications of the abutment and attachment components and the prostheses were recorded. Frequency of complications was evaluated. Data were analyzed using the Fisher exact test (alpha=.05).

RESULTS: Thirty-two auricular, 25 orbital, and 13 nasal prostheses were evaluated. The Kaplan-Meier analysis revealed an estimated mean survival time of 14.5 months for the patients' first prostheses. The survival times for the first implant-retained auricular, orbital, and nasal prostheses were 14.1, 13.4, and 17.6 months, respectively. The survival times for the second implant-retained auricular, orbital, and nasal prostheses were 14.4, 15.3, and 14.0 months, respectively.

CONCLUSIONS: Implant-retained extraoral prostheses had limited survival rates. The primary reasons for making new prostheses were discoloration, tearing, and mechanical failures of the acrylic resin substructure or retentive elements. Common complications were the need for clip activation, loosening of bar screws and abutments, and loss of attachment between silicone and the acrylic resin substructure. (J Prosthet Dent 2010;103:118-126).