Experimental subperiosteal implantation of porous Al2O3 ceramic for mandibular ridge augmentation

Porous Al2O3 ceramic material with pore size of 100-750 micrometers was used for implants placed subperiosteally as alveolar ridge augmentation onlays in six Cercopithecus monkeys. Clinical and radiographic examination during the postoperative period revealed rapid healing and anchorage of the implant in five of the animals. One implant was lost. The implants were retrieved after 4, 10, 11 and 12 months' implantation time. Histologic and microradiographic examination demonstrated fibrous and bone tissue invasion into the pore system at the base of the subperiosteal implant, with good anchorage of the ceramic material to the jaw. Only fibrous tissue was found to project into the ceramic openings on the implant sides facing the periosteum. Labeling of the mineralizing tissue was attempted using intravenously administered tetracycline (Reverin) and calcein (Calcein) at varying intervals prior to sacrifice, but the labeling results were not impressive.