Survival and Complication Rates of Fixed Restorations Supported by Locking-Taper Implants: A Prospective Study with 1 to 10 Years of Follow-Up

The aim of this 10-year follow-up study was to evaluate the implant survival and complication rates of fixed restorations supported by locking-taper implants.Over a 10-year period (January 2002 to December 2011) all patients referred to a single private practice for treatment with fixed restorations (single crowns, SCs; fixed partial prostheses, FPPs; fixed full arches, FFAs) supported by dental implants were considered for inclusion in the study. At each annual follow-up session, clinical, radiographic, and prosthetic parameters were assessed. The surviving implant-supported restorations were defined as "complication free" in the absence of any biological or prosthetic (mechanical or technical) complication. The cumulative implant survival and the "complication-free" survival of fixed implant-supported restorations were identified using the Kaplan-Meier method. The Log-rank test was used to identify correlations between the study variables.In total, 1494 locking-taper implants (727 maxilla, 767 mandible) were placed in 642 patients (356 males, 286 females). Nineteen implants (12 maxilla, 7 mandible) failed. Implant failures were attributed to lack of osseointegration (14 implants), peri-implantitis (4 implants), and mechanical overloading (1 implant). An overall 10-year cumulative implant survival rate of 98.7\% (98.3\% maxilla, 99.1\% mandible) was found. The implant survival rates did not significantly differ with respect to implant location, position, bone type, implant length and diameter, and type of restorations. Among the surviving implant-supported restorations (478 SC, 242 FPP, 19 FFA), a few biological (11/739: 1.4\%) and prosthetic (27/739: 3.6\%) complications were reported. The incidence of mechanical complications was low (3/739: 0.4\%), with three loosened abutments in three SCs (3/478: 0.6\%), and no abutment fractures; technical complications were more frequent (24/739: 3.2\%), with an incidence of decementation of 2.0\% (SC 2.0\%, FPP 1.6\%, FFA 5.2\%) and ceramic/veneer chipping/fracture of 1.2\% (SC 0.0\%, FPP 2.8\%, FFA 10.5\%). A 10-year cumulative "complication-free" survival of restorations of 88.6\% (SC 91.7\%, FPP 83.1\%, FFA 73.8\%) was reported. The complication rates differ significantly with respect to the type of restoration (p < 0.05).Fixed restorations on locking-taper implants seem to be a successful procedure for the rehabilitation of partially and completely edentulous arches