Short (8-mm) locking-taper implants supporting single crowns in posterior region: A prospective clinical study with 1-to 10-years of follow-up

摘要

Objective: The aim of this study was to evaluate the long-term outcome of short (8-mm) locking-taper implants supporting single crowns in the posterior regions and to analyze the influence of different factors on implant survival and implant-crown success rates. Materials and methods: Between June 2002 and September 2011, all patients referred to two private practices for treatment with short (8-mm) implants supporting single tooth restorations in posterior areas of both jaws were considered for inclusion in this study. At each annual follow-up session, clinical and radiographic parameters were assessed. Implant-crown success criteria included absence of pain, suppuration, mobility, and peri-implant radiolucency, distance between the implant shoulder and the first visible bone-to-implant contact (DIB) <1.5 mm after 12 months and not exceeding 0.2 mm for each following year, absence of prosthetic complications. The cumulative survival and implant-crown success were assessed using the Kaplan-Meier survival estimator; Chi-square test was applied to evaluate correlations between the study variables. The statistical analysis was performed at the patient and at the implant level. Results: Two hundred and fifteen implants (124 maxilla; 91 mandible) were placed in 194 patients (104 men; 90 women). Three implants failed (2 maxilla; 1 mandible). The 10-year cumulative survival rate was 98.4% (patient-based) and 98.5% (implant-based). Among the surviving implants, the mean DIB was 0.31 (±0.24), 0.43 (±0.29), and 0.62 (±0.31) mm at the 1-, 5-, and 10-year follow-up session; two biologic and three prosthetic complications were reported, for a 10-year cumulative implant-crown success rate of 95.8% (patient-based) and 95.9% (implant-based). The implant survival and implant-crown success rates did not differ significantly with respect to patients' gender, age, smoking habit, parafunctional habit, implant location, implant diameter, and bone type. Conclusions: The use of short (8-mm) locking-taper implants is a predictable treatment modality for the restoration of single tooth gaps of posterior segments of dentition.