Five-year results of this randomized-controlled study showed no increased risk of peri-implantitis for fully etched implants compared to hybrid-designed implants.

The difference in success rates is most likely attributed to the acid-etched surface characteristics. The greatest performance difference is observed in the conditions of poor quality or soft bone where the 3-year post-loading CSR are 96.8% (dual acid-etched) and 84.8% (machined-surfaced).

In this prospective study, the clinical outcome of 2-months loaded implants placed in the posterior jaws was evaluated after up to 3 years of functional loading. 405 Osseotite implants with microtextured acid-etched surface were consecutively placed in 11 fully and 164 partially edentulous patients (mean age 53.5 +/- 15.3 (S.D.) years) using a one-stage technique. 282 implants, supporting 154 restorations, were placed in the mandible, while 123 implants, supporting 75 restorations, were placed in the maxilla. A total of 99 single-tooth restorations, 119 short-span fixed bridges and 11 full-arch prostheses were applied. The mean time interval from surgery to connection of provisional restoration was 2.0 +/- 0.7 months. 9 failures were reported up to 3 years of follow-up; of these, 4 mandibular and 2 maxillary implants failed during the initial healing period (before prosthesis connection), while 3 mandibular implants failed after loading. No other complications occurred throughout the study. Life table analysis showed a cumulative survival rate of 97.5% for the mandible and 98.4% for the maxilla. Post-loading implant survival rate was 98.9% for the mandible and 100% for the maxilla. The excellent outcome of this interim report suggests that microtextured Osseotite implants in the posterior jaws may safely bear a functional load applied 2 months after insertion. The results of the present study are particularly encouraging for implants placed in the maxilla, since both a significant reduction of the healing period compared to the 6 months suggested by the classical Brånemark protocol, and an excellent post-loading function may be achieved also in low quality bone.