酸蚀处理对两种复合树脂表面封闭剂封闭效果的影响

目的 探究酸蚀处理对复合树脂表面封闭剂封闭效果的影响。方法 在140颗离体牙的颊、舌侧分别制备标准V类洞，进行复合树脂充填后随机分为7组（n=20）：不作表面封闭（C组）；不酸蚀，Permaseal封闭（P0组）；15 s酸蚀+Permaseal封闭（P15组）；30s酸蚀+Permaseal封闭（P30组）；不酸蚀，G-coat封闭（G0组）；15 s酸蚀+G-coat封闭（G15组）及30 s酸蚀+G-coat封闭（G30组）。每组中10颗离体牙进行冷热循环老化处理（5 ～ 55℃，1 000次循环，停留时间30 s），另10颗在生理盐水中浸泡24 h后直接进行微渗漏评价。以染料渗入法评价微渗漏程度。结果 任何条件下，P0组、P15组、P30组的组间比较冠方微渗漏等级无显著性升高或降低（P> 0.05）；冷热循环条件下，P30组较P0组龈方微渗漏等级显著升高（P< 0.05），G0组、G15组较G30组冠方微渗漏等级显著降低（P< 0.05），G0组较G30组龈方微渗漏等级显著降低（P< 0.05）。结论 （1）酸蚀处理对G-coat的封闭效果有显著影响，不作酸蚀处理可获得最佳封闭效果。（2）酸蚀处理对Permaseal在充填体冠方的封闭效果没有显著影响，对龈方的封闭效果有显著影响，延长酸蚀时间，龈方封闭效果有下降趋势。

Effect of acid ecthing on the sealing effect of two surface sealants

Objective This study aimed to evaluate the influence of acid etching before surface sealing on the sealing effect of two surface sealants. Methods V cavities were prepared on the buccal and lingual surfaces of one hundred and forty human teeth. All the samples were divided into seven groups (n=20):the control group without surface sealing (C group); the group sealing with Permaseal without etching (P0 Group); the group sealing with Permaseal after 15 s pre-etching (P15 Group); the group sealing with Permaseal after 30 s pre-etching (P30 Group); the group sealing with G-coat after polishing (G0 Group); the group sealing with G-coat after 15 s pre-etching (G15 Group) and the group sealing with G-coat after 30 s pre-etching (G30 Group). The specimens were analyzed with the dye penetration method. Results Under any condition, no significant differences in microleakage at the coronal margin were found among P0 group, P15 group and P30 group (P> 0.05). After thermocycling aging, the microleakage level at the gingival margins of specimens in the P30 group was significantly greater than that in the P0 group (P< 0.05). The microleakage level at the gingival margins of specimens in the G30 group significantly increased than that in the G0 group (P< 0.05), and the microleakage level of the specimens in the G0 group and the G15 group was significantly lower than that in the G30 group (P< 0.05), after thermocycling aging. Conclusion (1) The etching time significantly affected the performance of G-coat. Better performance is achieved without pre-etching. (2) No significant difference was found in the microleakage level between Permaseal with or without pre-etching at the coronal margin,while acid etching significantly affected the sealing effect at gingival margin. With the prolongation of etching time, the sealing effect of Permaseal showed a downward trend.