Five-mm-diameter implants without a smooth surface collar: Report on 98 consecutive placements

In recent years, indications for endosseous dental implants have been exten ded to include partially edentulous jaws with areas of limited bone density and bone volume. Wide-diameter implants are particularly well suited for t hese situations. The purpose of this paper was to report on 98 consecutivel y placed 5-mm-diameter implants without smooth surface collars. Eight impla nts failed-6 at second-stage surgery, and 2 after 1 year of loading (91.8% survival rate). Sixty percent of the remaining implants had no thread above the bone level after 1 year of loading. The authors discuss the possible c auses for failure and suggest guidelines to avoid failure.