10%抗坏血酸钠对外漂白后复合树脂充填体微渗漏的影响

目的观察10%抗坏血酸钠与含表面活化剂(Tween,0.2%)的10%抗坏血酸钠对经10%过氧化脲外漂白后复合树脂充填体微渗漏的影响。方法选取牙体完整健康的人离体前磨牙50颗,随机分为5组,第1组不漂白直接树脂充填,第2组用10%过氧化脲漂白后立即树脂充填,第3组漂白后将牙齿浸泡在人工唾液中3周再进行树脂充填,第4组漂白后先用10%抗坏血酸钠处理窝洞后再充填树脂,第5组漂白后先用含0.2%Tween的10%抗坏血酸钠处理窝洞后再进行树脂充填。然后,将5组样本进行2000个周期的冷热循环,2%亚甲基蓝染色24h,体视显微镜下观察剖面充填体的微渗漏情况。结果第1组微渗漏值最低,第2组微渗漏值最高,第3、4组微渗漏值显著高于第1组但与第2组无显著性差异(P>0.05);第5组渗漏值较第2组及第4组显著下降(P<0.05)。结论 10%过氧化脲外漂白致复合树脂充填体边缘微渗漏明显增加,含0.2%Tween的10%抗坏血酸钠处理窝洞可以有效减少该微渗漏的增加,延迟充填和单纯使用抗坏血酸钠均不能有效减少微渗漏。

Effects of 10% sodium ascorbate on microleakage of composite resin restorations after external bleaching

Objective To investigate the effects of 10% sodium ascorbate, 10% sodium ascorbate combined with a surfactan(Tween,0.2%) on the microleakage of composite resin restorations after external tooth bleaching with 10% carbamide peroxide. Methods Fifty extracted human premolars, intact and health, were randomly divided into five groups:group 1, direct composite resin filling without bleaching; group 2, composite resin filling immediately after bleaching with 10% carbamide peroxide; group 3, immersed in artificial saliva for three weeks after bleaching, then filled by composite resin; group 4, cavity treated with 10% sodium ascorbate after bleaching and then filled by composite resin; group 5, cavity treated with 10% sodium ascorbate combined with 0.2% Tween after bleaching and then filled by composite resin. After 2000 thermal cycles, teeth were immersed in 2% methylene blue for 24 hours, then the microleakage at resin/deatin interface was observed under stereomicroscope. Results Group 1 displayed the least amount of microleakage, while group 2 showed the greatest amount of microleakage, group 3 and group 4 behaved similarly to group 2, having great amount of microleakage, showing no significant difference (P>0.05); the microleakage of group 5 decreased significantly (P<0.05) compared to group 2 and group 4. Conclusion The microleakage increased significantly after external bleaching with 10% carbamide peroxide, and decreased when cavities treated with 10% sodium ascorbate combined with 0.2% Tween. However, both delay filling and treated with sodium ascorbate could not effectiely decrease the microleakage.