漂白剂对玻璃离子水门汀类材料充填Ⅴ类洞边缘微渗漏的影响

目的评估漂白凝胶和洁白牙贴对3种不同的玻璃离子水门汀类材料边缘微渗漏的影响。方法在45颗离体健康前磨牙的颊舌侧制备Ⅴ类洞,随机分为A、B、C组,分别使用加强型玻璃离子水门汀KetacTM Molar Easymix、复合体F2000、复合体Dyract AP充填,每个大组再分为3个亚组,第1组和第2组分别使用质量分数14％过氧化氢（HP）洁白牙贴和10％过氧化脲（CP）凝胶进行漂白,第3组为对照组。所有样本置入37 ℃蒸馏水中保存7 d后冷热循环500次,然后进行漂白。漂白21 d后置于碱性品红溶液中染色24 h,沿牙体长轴通过充填体中央颊舌向剖开牙齿,体视显微镜下观察并测量染料渗入窝洞壁的深度。结果2种漂白方式对充填体边缘微渗漏的影响没有明显差异（P>0.05）;与对照组相比,2种漂白方式对B、C组的微渗漏均没有产生明显影响（P>0.05）,但均可使A组的微渗漏增加（P<0.05）。结论10％CP凝胶和14％HP洁白牙贴对充填体边缘微渗漏的影响无明显差异;漂白不会影响复合体的微渗漏,但会增加加强型玻璃离子水门汀的微渗漏。

Effects of bleaching agents on the microleakage of class V cavities restored with glass-ionomer cements

Objective To evaluate the effects of a bleaching gel and a whitening strip on the microleakage of three different glass-ionomer cements.Methods Forty-five freshly extracted human premolars were used and class Ⅴ cavity was prepared on the buccal and lingual surfaces.The teeth were randomly assigned to A,B and C groups and restored as follows:Conventional strengthen glass-ionomer cement(KetacTM Molar Easymix),compomer(F2000) and compomer(Dyract AP).Teeth were kept in distilled water at 37 ℃ for 7 days.Then the specimens were thermocycled for 500 times.Each group was randomly divided into 3 subgroups which were treated for 21 days with one of the following:Whitening strip(14% hydrogen peroxide),bleaching gel(10% carbamide peroxide),or distilled water(control).After bleaching,the teeth were placed in a solution of basic fuchsin dye for 24 hours,then the teeth were sectioned longi-tudinally to evaluate the dye penetration.The depth of staining along the tooth restoration interface was recorded with a stereomicroscope.Results There were no signicant differences between the two bleaching agents in microleakage of restorations(P>0.05).The two bleaching agents did not significantly affect the microleakage of compomer(P>0.05),whe-reas the microleakage of glass-ionomer cement in the experimental groups was higher than that in the control group(P<0.05).Conclusion There are no significant differences in microleakage of restorations between bleaching gel(10% carbamide peroxide) and whitening strip(14% hydrogen peroxide).The two bleaching agents do not significantly affect the microleakage of compomer but adversely affect the microleakage of strengthen glass-ionomer cement.