[Hydroxyapatite implant for human periodontal osseous defects].

The purpose of this study was to evaluate the efficacy of porous hydroxyapatite (HAP) as an implant material into human periodontal defects. Thirty three patients affected by marginal periodontitis were studied. Following initial therapy, 44 periodontal osseous defects received grafts of HAP granules and blocks during flap surgery. Radiographic and various clinical examinations were performed before surgery and 1 and 2 weeks, and 1, 2, 3, 6 and more than 6 months after surgery. The results were as follows: 1. Postsurgical inflammation of the gingiva disappeared in a short time. Further more open wounds and discharges of HAP disappeared in the first month. There were no clinical problems in the sites receiving HAP implantation. 2. Radiographic demarcation lines between the implanted HAP and the surrounding alveolar bone became unclear at the beginning of bone repair. 3. At six months after surgery, the mean values of gingival recession, decrease in pocket depth and clinical attachment gain were respectively 0.9 mm, 2.7 mm, 1.9 mm. Additional observation beyond 6 months showed an attachment gain of 2.0 mm. 4. The attachment gain was less in the cases of one wall osseous defect and of furcation involvement in lower molars. These results suggest that HAP implantation is clinically effective, however, careful application is needed for the cases of one wall osseous defect or furcation involvement.