Complications and survival rates of 55 metal-ceramic implant-supported fixed complete-arch prostheses: A cohort study with mean 5-year follow-up

Abstract

Statement of problemLong-term outcomes with metal-ceramic (MC) implant-supported fixed complete dental prostheses (IFCDPs) are scarce. PurposeThe purpose of this retrospective study was to assess the rate of biologic and technical complications in a cohort of edentulous patients treated with MC IFCDPs by residents after a mean clinical follow-up of 5 years (range: 1 to 12 years). Material and methodsForty-one participants with 55 MC IFCDPs underwent a single-visit comprehensive examination that included a medical and dental history review and clinical and radiographic examinations. All supporting implants and prostheses were examined for biologic and technical complications. Life table analysis and Kaplan-Meier survival curves were calculated. ResultsOf 359 moderately rough surface dental implants, 2 had failed in 1 patient after 11 years of functional loading, yielding a cumulative implant survival rate of 99.4%. Owing to the implant failure, 1 of 55 edentulous arches restored with IFCDPs failed, yielding a cumulative prosthesis survival rate of 98.2% after mean observation period of 5.0 years. Soft tissue recession was the most frequent minor biologic complication (annual rate 7.8% at the prosthesis level) for both cement and screw-retained IFCDPs (group C and S), and peri-implantitis (annual rate 1.6% at the implant level) the most frequent major biologic complication. Wear of porcelain (annual rate 8.0% at the prosthesis level) was the most frequent minor technical complication for both groups, and fracture of porcelain (annual rate 0.8% at the dental-unit level) was the most frequent major technical complication. Minor complications were the most frequent in both the groups (cement and screw retained). ConclusionsHigh implant and prosthesis survival rates (above 98%) were achieved, yet substantial complication rates were encountered. The most frequent major biologic complication was peri-implantitis, with a 5-year implant-based rate of 8% (95% confidence interval [CI]: 5.8-11.1), whereas the most frequent major complication was fracture of porcelain with a 5-year dental unit-based rate of 4%. The estimated cumulative rates for “prosthesis free of biologic complications” were 50.4% (95% CI: 36.4% to 63.0%) at 5 years and 10.1% (95% CI: 3.5% to 20.8%) at 10 years, whereas for “prosthesis free of technical complications,” they were 56.4% (95% CI: 41.7% to 68.8%) at 5 years and 9.8% (95% CI: 3.2% to 21.0%) at 10 years.