Long-term retrospective study of narrow implants : 1-12 years of cumulative success rate

Abstract

The selection of implant diameter depends on the type of edentulism, the amount of the residual bone, the volume of space available for the prosthetic rehabilitation, the emergence profile, and the type of occlusion. Narrow-diameter implants (NIs) were designed specifically for decreased interradicular bone, a thin alveolar crest and the replacement of teeth with small cervical diameters, like mandibular incisors and maxillary lateral teeth. The objective of this study was to evaluate long term survival and success rates of the NIs placed with various implant system, and analyze the associated biological and mechanical complications.A total of 338 patients (male = 45.6%, female = 54.4%) who received 541 NIs (≤3.5 mm in diameter) were enrolled in this study. Life table analysis with the cumulative survival rate and success rate was calculated. The results are as follows: Six implants were lost in the maxilla, while 3 implants were lost in the mandible. The cumulative survival rates of NIs were 98.1% and 98.5% for the implant- and subjectbased analysis, respectively. The cumulative success rates were 91.8% and 93.8% for the implant- and subject-based analysis, respectively. The infection was the highest reason of the biological complication. The most frequent mechanical complication was the decementation. The mechanical complications were more frequent than the biological complications.In conclusion, the use of NIs could be suggested in the narrow alveolar ridge or narrow mesiodistal space, on the basis of the high survival rate with less complication in this study.