BONE REACTIONS TO EARLY OCCLUSAL LOADING OF 2-STAGE TITANIUM PLASMA-SPRAYED IMPLANTS - A PILOT-STUDY IN MONKEYS

This pilot study analyzed the bone reactions to early loaded titanium plasma-sprayed implants. A total of 24 titanium plasma-sprayed implant s (12 in the maxilla and 12 in the mandible) (Primary Healing implant Legnano) were inserted into four Macaca fascicularis monkeys with inst ruments specially designed to obtain a precise fit of the implant in t he bone socket. A metal superstructure was cemented into 10 mandibular and 10 maxillary implants 15 days after implant insertion. The four r emaining implants were used as controls. Eight months after implant pl acement a block section was carried out the defect was filled with non resorbable hydroxyapatite, and ail 24 implants were retrieved. The imp lants were treated to obtain thin ground sections that were examined u nder normal and polarized light Histologic analysis showed that bone w as observed around the implant surface in all implants. Morphometric a nalysis demonstrated that bone lined 67.2% (SD = 3.1%) of the maxillar y implant surface and 80.71% (SD = 4.6%) of the mandibular implant sur face. No differences were found in the percentage of bone-implant cont act in the control implants. In the loaded implants, however the bone around the implants had a more compact appearance. The study demonstra ted that it is possible to obtain a high percentage of bone implant co ntact in early loaded titanium plasma-sprayed implants.