Background: There are limited clinical data available for immediately or early loaded implants placed in posterior mandibles and maxillas. This is probably because bone density often is low in these areas, making it difficult to establish good initial implant stability. By eliminating countersinking and using slightly tapered implants (Brånemark System , Mk IV, Nobel Biocare AB, Gothenburg, Sweden), however, high initial implant stability might be achieved in these regions.
Purpose: The aim of this study was to investigate the possibility of early application of implant function in oral locations where the bone density is often low, namely the maxilla and posterior mandible.
Materials and methods: Thirty-one patients were included consecutively in the study, and 36 edentulous areas in maxillas and posterior mandibles were treated. All patients were nonsmokers in good general health. Bruxism and uncontrolled periodontal disease were exclusion criteria. One hundred twenty-four machined-surface implants were placed using an insertion torque of at least 40 Ncm. Temporary prostheses with narrow occlusal platforms, flat cusps, and light occlusal contacts were generally placed within 1 week and not exceeding 20 days from implant placement.
Results: Of the 124 implants installed, 4 failed, 1 in each of four patients, giving an overall survival rate of 96.8% after 18 months. Two implants failed in maxillas and two in mandibles. One implant in a maxilla and one in a mandible were lost in an early stage, and the other two were lost a few months after placement. The prostheses' survival was 100%.
Conclusions: This study shows that early implant function rehabilitation in maxillas and posterior mandibles is viable using the present clinical protocol. The results are comparable with those of conventional two-stage protocols.