排龈线预防牙体修复悬突的实验研究

Experimental Study of Gingival Retraction Cord forPreventing Overhanging in Filling V Class Cavities

目的 探讨使用排龈线能否使牙体Ⅴ类洞充填时产生悬突的机会减少。 方法 在杂种狗上、下颌牙的颊侧牙颈部形成部分位于龈下的牙体缺损模型 36个 ;分成两组 ,实验组用排龈线排龈后复合树脂充填 ,对照组则直接用复合树脂充填。 1,3,6个月后测定模型的龈沟液 (GCF)中天门冬氨酸转氨酶 (AST)。 结果 使用排龈线组与对照组的AST水平在 1个月时差异无显著性 (P >0 0 5 ) ,3,6个月使用排龈线组GCF AST明显低于对照组 ,差异有显著性 (P <0 0 5 )。 结论 动物实验中充填涉及龈下的牙颈部缺损时利用排龈线预防悬突产生是可行的 ,可以防止悬突对牙周组织的损害。

Objective To observe whether it can prevent overhanging in filling Ⅴ class cavities when using gingival retraction cord in animal experiments. Methods The 36 dental Ⅴ class cavity animal models were made in the buccal surfaces of dogs’ maxillary and mandibular teeth. The teeth were randomly devided into 2 groups. One group was filled with composite resin after using retraction cord to retract gingiva. The other group was filled directly. Crevicular fluid aspartate aminotransferase levels were measured on 1 month, 3 months and 6 months after operation. Results 1 month after operation, the differences of crevicular fluid aspartate aminotransferase(AST) levels between the experimental group and the control group were not significant(P>0.05). But 3 months and 6 months after operation, the differences of AST levels between the experimental group and the control group were significant (P<0.05). Conclusion To use retraction cord for preventing overhanging in filling Ⅴ class cavities and then prevent the damage of periodontal tissue in animal experiments.