新鲜离体牛牙周韧带强度与组织结构的关系

目的 研究牙周膜宽度和纤维含量对牙周膜强度的影响.方法 取有完整牙列的牛新鲜离体下颌骨制备成5 mm×2 mm×10 mm的牙-牙周膜-牙槽骨复合体试件,在体视显微镜下测量牙周膜宽度,并在万能测试机上加载拉应力至试件断裂,记录应力-应变曲线,断端用天狼星染色,分析断面纤维含量,记录数据.结果 得到牙周膜宽度与其最大应力的关系Y＝9.786e~(-3.6693x),牙周膜宽度与其生理极限应力的关系Y=e~(2.188(-3.953)x),纤维百分比与其牙周膜的最大应力关系Y=20.788-0.755x+0.007x~2,纤维百分比与其生理极限应力的关系Y=1.39e~(-14)·x~(7.666),初始生理应力为0.28 N/mm~2.结论 随着牙周膜宽度的减少和纤维含量的增加牙周膜的强度增加.

Relationship Between Tissular Structure and Strength of Fresh Bull Periodontal Ligament

Objective To study the relationship between the width and the content of fiber in peridontal ligament (PDL) and the strength of peridontal membrane. Methods Fresh mandible of bull was obtained to prepare for a 5 mm×2 mm×10 mm cuboid including teeth, peridontal membrane, and alveolar bone. The width of the PDL was measured under a stereomicroscope. Pull stress was loaded on the test piece until it broke. The stress-strain curve was recorded. The broken ends of the PDL was dyed with siriue to analyze the content of fiber. Results The relationship between the width of the PDL and the maximum stress was expressed as Y＝9.786e~(-3.6693x). The relationship between the width of the PDL and the physiological ultimate stress was expressed as Y=e~(2.188(-3.953)x). The relationship between the percentage of fiber and maximum stress was expressed as Y=20.788-0.755x+0.007x~2. The relationship between the percentage of fiber and the physiological ultimate stress was expressed as Y=1.39e~(-14)·x~(7.666). The initial physiological stress was 0.28 N/mm~2. Conclusion The strength of PDL increases with the decrease of PDL width and increase of fiber content.