Immediate/early function of Brånemark System TiUnite implants in fresh extraction sockets in maxillae and posterior mandibles: an 18-month prospective clinical study.

BACKGROUND: The advantages of placing implants in fresh extraction sockets and putting them in immediate/early function are many. A predicable protocol opens the possibility of performing a single surgical procedure, giving the patient a temporary prosthesis immediately, and minimizing the shrinkage of hard tissue and soft tissue recession.

PURPOSE: The aim of the present study was to develop a strict protocol for and to evaluate the feasibility of immediate/ early function on implants placed in fresh extraction sockets located in maxillae and posterior mandibles, including defects around the implants treated according to a regenerative procedure.

MATERIALS AND METHODS: Nineteen patients were treated after tooth extraction according to an immediate function protocol and were observed for 18 months. Fifty Mk IV TiUnite (Nobel Biocare AB, Göteborg, Sweden) implants were installed in partially edentulous areas in maxillae (n = 17) and posterior mandibles (n = 5). Implants were installed directly into the alveoli, and the temporary prostheses were connected immediately after surgery (n = 11) or within 7 days, that is, an "early function" procedure (n = 11). Thirteen implants did not require any type of regenerative procedure, whereas the remaining 37 implants had filling with autogenous bone, 4 of which also had a resorbable membrane. Standardized intraoral radiographs were taken for evaluation of marginal bone level, and 38 of the implants were systematically checked by resonance frequency analysis.

RESULTS: All patients were followed for 18 months, and none of the 50 implants failed. However, one implant showed signs of failure after 6 weeks, but once the occlusal load was removed, the implant regained its stability completely, no longer demonstrated symptoms, and could be used successfully for prosthetic rehabilitation. The mean value of the implant stability quotient was 60 at baseline (range 45-75) and 63 after 6 months (range 46-75). The marginal bone resorption was 0.9 mm (SD 1.1 mm; n = 48) 18 months after implant insertion (1 year after final prosthesis).

CONCLUSION: The immediate placement of implants into fresh extraction sockets combined with immediate/early function procedures seems to be a safe and reliable procedure when using a strict protocol.