Submerged Alumina Dental Root Implants in Humans: Five-year Evaluation

This article describes the placement, success rate, and evaluation of an experimental alumina (Al2O3) ceramic dental implant at a mean placement time of 5 years. The study compared the longevity of a submerged implant of the same root design and a refined surgical technique with previously reported studies of the implant exposed to the human oral environment during initial healing. A 54% success rate was achieved for 29 implants placed in the maxillae and mandible, all restored with cast gold dental crowns. A significant difference (p = 0.05) appeared between success and failures at 7.8 months following placement. Crown/root ratio slopes were an earlier and more sensitive indicator of potential success or failure than the bone height slopes. Computer analysis revealed no apparent correlation between implant mobility and/or pocket depths and implant longevity. Delayed implant root fractures and a cast post fracture occurred in 20% of the implants that survived.