評估醫用硫酸鈣在拔牙後齒槽嵴保存之效果—臨床比較與組織分析

Abstract

Background: Alveolar bone resorption in patients with periodontal disease is an important issue for future implant therapy, there is little information about the dimensional changes of alveolar ridge following tooth extraction. The purposes of this study are to investigate 1) the effectiveness of either calcium sulfate or collagen material for ridge preservation in extraction sockets by measuring the changes of alveolar bone height and width clinically; and 2) the histologic outcome of calcium sulfate. Methods: 21 single root tooth extraction sites were selected and randomly assigned to calcium sulfate group (7 sites), collagen plug group (7 sites), and control group (7 sites). An occlusal stent was fabricated to measure the changes of alveolar height and width (at 3 and 5 mm level below alveolar crest). The measurements, right after extraction, of the alveolar bone height and width were compared with those data at 1, 2, and 4 months postoperatively. Two representative cases with control and treated teeth were selected for histologic analysis of socket healing after ridge preservation. At each time point post-extraction, a trephine core was harvested from the extraction site for histologic analysis. Results: Clinically, sockets augmented with either calcium sulfate or collagen plug showed better hemostasis and more rapidly epithelialization than control during early period of wound healing. Calcium sulfate group exhibited less shrinkage of the alveolar bone height at 1 month postoperatively than other two groups (1.8 mm vs. 2.5 mm), especially at the mid-buccal aspect. However, there were no significant changes of bone width at 2 levels of measurements among three groups at 1, 2, and 4 months postoperatively. Histologically, new bone formation was noted in all specimens. There were still a few residual particles remained in the calcium sulfate group, while the extent of new bone formation was similar at one month’s specimens. At two month’s follow-up, the volume of new bone increased in both groups. Conclusion: Both calcium sulfate and collagen plug had good wound healing of extraction sockets. Besides, therapy with calcium sulfate seemed to have some benefit to prevent the ridge collapse after extraction at limited period of the present study. Based on histological data, calcium sulfate might be a good bone substitute for ridge preservation in extraction sockets because it was completely resorbed shortly after implantation and did not interfere with the healing of extraction sockets.