Porous titanium dental implants in primates and humans.

Abstract

A series of 30 cylindrical implants employing sintered powder metal exteriors to promote bone ingrowth have been employed to support bridges and crowns in Rhesus monkeys for periods exceeding 36 months. Clinical indicators demonstrated successful function during the period of the experiments for 24 of the 30 implants. The four implants which did not perform well clinically were analysed by histology and found to be locally infected. Implants retrieved at various times after function were analysed by histomorphometric techniques. In all successful implants bone had grown into the porous exterior of the implant and was found to be supporting the loads of mastication. Long term bone remodeling under stress was evaluated quantitatively. It was found that for periods of function exceeding three years, remodeling which was not present in one and two year specimens was detectable. Clinical success was attributed to stabilization accomplished by the bone ingrowth. Clinical and histological results were analysed using a computerized data handling system, and correlations between histology and clinical performance were attempted. In human experiments eight patients have received implants which will support bridges used as distal extensions in the mandible. At this writing, the results are short term and comparison with the animal experiments difficult.