屏障膜放置时间与牙周再生量关系的动物实验研究

目的：探讨行引导组织再生术时，达到最大量牙周再生所需屏障膜在体内保留的最短时间。方法：在杂种犬下颌第3、4前靡牙近中根颊侧制备“U”型牙周缺损，表面覆盖ePTFE膜，置留时间分别为2、3、4、8周，以不放膜组（右下第2前磨牙）为空白对照，术后8周处死动物，标本作组织学分析。结果：膜3且的牙槽骨、牙骨质再生量显著大于空白对照组，上皮根移被明显抑制，但放膜3、4、8周3组之间的牙周再生量无显著性差异。结论：达到最大量牙周再生所需屏障膜放置的最短时间为3周。

The experimental study onrelationship between time for placement of a barrier membrane and periodontal regenerationin dogs

AIM: The optimal time for placement of a barrier membrane be established in guided tissue regeneration needed to achieve maximum periodontal regeneration. METHODS: Periodontal defects were created on buccal side of mesial root of mandibular third and fourth premolars in dogs. An expanded polytetrafluoroethylene(ePTFE) membrane was used to left in place for 2, 3, 4 and 8 weeks respectively. In the control defects(right mandibular second premolar), no membrane was used. All animals were sacrificed at the end of 8 weeks. Study and histologic analysis were performed. RESULTS: The group in which the membranes were left in place for 3 weeks showed more new bone and new cementum and less junctional epithelium than the controls. However, no significant difference of periodontal regeneration was found among the 3-week, 4-week and 8-week groups. CONCLUSION: The shortest time for placement of a barrier membrane needed to achieve maximum periodontal regeneration is 3 weeks.