Dental Research Center, Operative Dentistry, Hamadan, Iran.
Oper Dent. 2011 Mar-Apr;36(2):213-21. doi: 10.2341/10-215-L. Epub 2011 Jun 24.
Composite restorations frequently have gingival margins apical to the cemento-enamel junction (CEJ). Microleakage at the cementodentinal margins is one of the most important causes of failure in these restorations. The current study evaluated microleakage at the occlusal and gingival margins of Class II packable composite restorations using resin-modified glass ionomer and flowable composite as liners, using the two-step etch-and-rinse and self-etch dentin-bonding systems.
This in vitro study was carried out on 48 intact human premolars. Class II preparations were made with the gingival margins placed 1.0 mm apical to the CEJ. The teeth were randomly assigned to six groups of 16 boxes and restored using the following techniques: Group 1: Single Bond (3M ESPE) + Filtek P60 (3M ESPE); Group 2: Clearfil SE Bond (Kuraray) + Filtek P60; Group 3: Single Bond + Filtek Flow (3M ESPE) + Filtek P60; Group 4: Clearfil SE Bond + Filtek Flow + Filtek P60. Group 5: Single Bond + Fuji II LC (GC) + Filtek P60; Group 6: Clearfil SE Bond + Fuji II LC + Filtek P60. The restorations were thermocycled for 1000 cycles at 5{degree sign}C and 55°C, soaked in 2% methylene blue for 48 hours, then sectioned mesiodistally and viewed under a stereomicroscope for leakage at the gingival margin. The data were statistically analyzed using the Kruskal-Wallis, two-way ANOVA and Mann-Whitney U-tests.
The resin-modified glass-ionomer liner demonstrated significantly less leakage than flowable composite (p<0.05). There was no difference between restorations with flowable resin composite liners and those without the liner; in addition, no significant difference was observed between the two kinds of adhesive systems.
The current study supports the use of resin-modified glass ionomer as a liner in closed-sandwich technique to decrease microleakage of Class II packable composite restorations, applying either the two-step etch-and-rinse or the self-etch dentin adhesive system.
复合树脂修复体的龈边缘常位于牙釉牙骨质界（CEJ）之上。牙本质粘结剂边缘的微渗漏是这些修复体失败的最重要原因之一。本研究采用两步酸蚀-冲洗和自酸蚀牙本质粘结系统，评价了用树脂改良型玻璃离子水门汀和流动复合树脂作为衬垫的 II 类可填压复合树脂修复体在牙合面和龈边缘的微渗漏。
本体外研究共使用 48 颗完整的人前磨牙。龈边缘置于 CEJ 上方 1.0mm 处制备 II 类牙体预备。将牙齿随机分为 6 组 16 个盒，采用以下技术进行修复：组 1：Single Bond（3M ESPE）+Filtek P60（3M ESPE）；组 2：Clearfil SE Bond（Kuraray）+Filtek P60；组 3：Single Bond+Filtek Flow（3M ESPE）+Filtek P60；组 4：Clearfil SE Bond+Filtek Flow+Filtek P60。组 5：Single Bond+Fuji II LC（GC）+Filtek P60；组 6：Clearfil SE Bond+Fuji II LC+Filtek P60。修复体经 5°C 和 55°C 热循环 1000 次，在 2%亚甲蓝中浸泡 48 小时后，沿近远中方向切割，在体视显微镜下观察龈边缘的渗漏情况。采用 Kruskal-Wallis、双向方差分析和 Mann-Whitney U 检验对数据进行统计学分析。
树脂改良型玻璃离子水门汀衬垫的渗漏明显少于流动复合树脂（p<0.05）。有流动复合树脂衬垫和无衬垫的修复体之间无差异；此外，两种粘结系统之间也无显著差异。
本研究支持在闭盒技术中使用树脂改良型玻璃离子水门汀作为衬垫，以减少 II 类可填压复合树脂修复体的微渗漏，无论应用两步酸蚀-冲洗或自酸蚀牙本质粘结系统。
