INITIATION OF ALVEOLAR RIDGE AUGMENTATION IN THE RAT MANDIBLE BY SUBPERIOSTEAL IMPLANTATION OF OCTACALCIUM PHOSPHATE

The study was designed to investigate the process of bone formation ca used by implantation of octacalcium phosphate as well as stability of the bone formed at the alveolar ridge. Synthetic octacalcium phosphate was implanted into a subperiosteal pocket in the rat mandible. Bone f ormation at the alveolar ridge was examined radiographically and histo logically between 1 and 48 week(s) after implantation. Radiopacity of the octacalcium phosphate implant became obvious in week 2. Osteogenes is was initiated from the bone surface near the implantation site and multinucleated giant cells appeared on the implanted octacalcium phosp hate in week 1. More apposition of new bone was observed on the implan ted octacalcium phosphate in week 2 or later. Some implants were direc tly enclosed by newly formed bone and no cellular component was seen b etween the implant and the bone matrix. Many octacalcium phosphate imp lants were enclosed by bone, whereas the augmented ridge was not seen radiographically in week 24 or later. If its persistence can be improv ed, octacalcium phosphate could be used to augment atrophic alveolar r idges. (C) 1997 Elsevier Science Ltd.