[Clinical study of tissue preservation of extraction socket with Bio-Oss collagen and acellular dermal matrix].

To evaluate the clinical and histological results of extraction socket preservation using Bio-Oss collagen and acellular dermal matrix (ADM).From November 2005 to June 2006, a total of 11 cases underwent extraction socket preservation with Bio-Oss collagen and ADM in 14 extraction sites. Ten cases with 10 teeth undergoing extraction without bone graft served as control group. Clinical and histological examinations were conducted. Pre-and postoperative alveolar ridge width and attached gingival width were measured and statistically analyzed.All the grafted sockets healed uneventfully except one. Thirteen implants were placed 3 - 5 months after extraction. After 4 to 6 months permanent restorations were delivered. The mean follow-up time was 27.9 months (24 to 31 months). In the control group the sockets healed uneventfully, while hard and soft tissue collapsed obviously 3 months after extraction. No significant difference was found in the width of alveolar ridge and attached gingiva before and after extraction in the bone graft group (P > 0.05). The width of alveolar ridge before (7.69 + or - 0.48) mm and after extraction (7.68 + or - 0.48) mm and in the width of attached gingiva before (4.36 + or - 1.02) mm and after extraction (4.32 + or - 0.98) mm in the bone graft group (P > 0.05). Histological examination showed adequate new bone formation around Bio-Oss particles 3 months after operation. The specimen was free of inflammatory cells.It's effective to preserve the extraction sockets with Bio-Oss collagen and ADM and the short-term results were predictable.