摘要
目的 评价两种不同抗氧化剂及不同处理时间对内漂后充填树脂微渗漏的影响,为临床选择合适的抗氧化剂及最佳处理时间提供理论依据.方法 将120颗离体前磨牙随机分为10组(n=12),A组:未漂白组,B组:漂白组,C组:10％SA组,D组:含0.2％Tween 80的10％SA组,试验组根据内漂白后抗氧化剂处理时间不同(10 min、30 min、60 min、120 min)又分为4个亚组(C1/C2/C3/C4,D1/D2/D3/D4),各组处理后行树脂充填窝洞,所有样本进行冷热循环后,每组随机选取10颗样本置于2％亚甲基蓝染色24h,体式显微镜下观察充填树脂边缘微渗漏的情况.每组剩余两个样本于扫描电镜下观察充填树脂粘接界面的微观形貌特点.结果 A组微渗漏值明显小于B组(P＜0.001),C1、C2、C3组间有统计学差异(P＜0.001),D2、D3、D4组间比较有统计学意义(P＜0.05),C2/C3/C4、D1～D4组与B组比较差异有统计学意义(P＜0.05),D4与A组间比较有统计学差异(P=0.0145).扫描电镜观察可见,B组充填树脂与牙体组织间可见明显间隙,且裂隙范围最大.C1-C4粘接界面的裂隙逐渐减小,未形成良好的粘接界面,D1组粘接界面存在间隙,随着处理时间的延长,充填树脂与牙体组织结合逐渐紧密,D4组形成了良好的粘接界面.结论 死髓变色牙内漂白后,应用10％SA凝胶处理60 min可使充填树脂的微渗漏值达到最小,而采用含0.2％Tween 80的10％SA凝胶处理10 min可明显减小其微渗漏值,随着处理时间的延长,充填树脂的微渗漏值逐渐减小,含0.2％Tween 80的10％SA凝胶处理效果明显优于单纯应用10％SA凝胶.
Abstract
Objective To evaluate the effection of two different antioxidants and the treating time on the microleakage of filling resin after intracoronal bleaching.Methods One hundred and twenty extracted premolars were randomly divided into ten groups(n=12).Group A:unbleached group,Group B:bleached group,Group C:10％SA gel,Group D:10％SA gel with 0.2％Tween 80.According to the treatment time of the antioxidant(10 min,30 min,60 min,120 min),the ex-perimental group was further divided into four subgroups(Cl/C2/C3/C4,D1/D2/D3/D4).Then the cavity was fillled with composite resin.After thermal cycles,ten samples in each group were put into 2％methylene blue for 24 hours.And the microleakage of filled resin was observed at buccolingual under stereomicroscope.The micromorphology of the bonding interface in the remaining samples was observed with scanning electron microscope.Results The microleakage of group B were apparently higher than the group A(P＜0.001).There were apparent differences between C1、C2 and C3(P＜0.001),D2、D3 and D4,C2/C3/C4 and B(P＜0.05),D1/D2/D3/D4 and B,D4 and A(P=0.0145).The obvious gap between the filling resin and dental tissues was observed by SEM in group B,and the amount of gaps was the largerest in all groups.The gap decreased gradually and the the bonding interface was not well formed in group C.There was obvious gap in group D1.And as the treating time was extended,the filling resin was well integrated with dental tis-sue,the bonding interface was well formed in group D4.Conclusion When the treating time of 10％sodium ascorbate gel was 60 min,the microleakage of filling resin was the minimum after intracoronal bleaching.The microleakage of fill-ing resin decreased distinctly while applying 10％sodium ascorbate gel combined with a surfactan(Tween 80,0.2％)for 10min.As the treating time was extended,the amount of microleakage in group D was gradually decreased.Effectiveness of 10％sodium ascorbate hydrogel combined with a surfactan(Tween 80,0.2％)was obviously better than 10％sodium ascorbate hydrogel.
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