三种方法修复薄弱根管冠方微渗漏的体外评价

目的评价可塑型纤维桩、预成纤维桩及根管重塑后预成纤维桩修复薄弱根管后的冠方微渗漏情况。方法选择正畸拔除上颌第一前磨牙36颗，制备形成薄弱根管。将30颗样本牙随机分为3组，A组可塑型纤维桩核系统修复、B组根管重塑后预成纤维桩核系统修复，C组预成纤维桩核系统修复，另外6颗为对照组。所有样本进行5℃-55℃冷热循环5000次后，置于0．5％碱性品红溶液中24h。将试件纵向剖开为2部分，在体视显微镜下观察各剖面修复材料与根管壁之间的微渗漏情况。用Kruskal—Wallisf法进行统计分析。结果3种方法修复后修复材料与根管牙本质之间均存在微渗漏现象，3组间无统计学差异（P〉0．05）。结论在本实验条件下，3种方法修复薄弱根管对冠方微渗漏的影响相近。

An in vitro evaluation of coronal microleakage of three restoration systems for weakened root canals

Objective To evaluate the coronal microleakage of three resin composite restorations systems for weakened root canals. Methods Thirty-six human maxillary premolars extracted for orthodontic purpose were collected, flared root canals of these teeth prepared and randomly divided into 3 groups with 10 teeth in each group, Group A： restored with a novel light-curable plastic FRC post system, Group B ： rehabilitated with a thick layer of Z350 composite and a composite resin core, Group C： restored with preformed glass fiber posts and a composite resin core. The other six teeth served as the control. After exposed to 5~C-55~C for 5000 cycles of thermocyeling,the specimens were stained in a solution of 2% basic fuchsin for 24 hours. Longitudinal sections were prepared and examined by a stereomicroscope for assessment of microleakage. The data were analyzed by Kruskal-Wallis test. Results The microleakage was observed in all the 3 groups. There were no significant differenc among the 3 groups in microleakage （ P 〉 0. 05 ）. Conclusion The present study suggests that the three systems for restoring flared root canals had similar effect on microleakage.