Sharafeddin F, Yousefi H, Modiri Sh, Tondari A, Safaee Jahromi Sr
Dept. of Operative Dentistry, Biomaterial Research Center, School of Dentistry, Shiraz University of Medical Science, Shiraz, Iran.
Dentist.
J Dent (Shiraz). 2013 Sep;14(3):90-5.
Microleakage is one of the most frequent problems associated with resin composites, especially at the gingival margin of posterior restorations. Insertion of fibers in composite restorations can reduce the total amount of composite and help to decrease the shrinkage.
The aim of this study was to evaluate the effect of polyethylene fiber inserts on gingival microleakage of class II composite restorations using two different adhesive systems.
In this experimental study, class II cavities were prepared on 60 premolars. The gingival floor was located 1.0 mm below the CEJ. Dimension of each cavity were 3 mm buccolingually and 1.5 mm in axial depth. The specimens were divided into 4 groups according to the adhesive type and fiber insert (n=4). Single bond and Clearfill SE bond and Filtek p60 were used to restore the cavities. In groups without fiber inserts composite was adapted onto cavities using layering technique. For cavities with fiber inserts, 3 mm piece of fiber insert was placed onto the composite increment and cured. The specimens were stored in distilled water at 37(o)C for 6 months. All specimens were subjected to 3000 thermo-cycling. The tooth surfaces except for 1 mm around the restoration margins covered with two layers of nail varnish .The teeth were immersed in 2% Basic Fuchsin for 24 hours, then rinsed and sectioned mesiodistally. The microleakage was determined under a stereomicroscope (40X). Data were statistically analyzed by Kruskal-wallis and Mann-Whitney U tests (p< 0.05).
The Kruskal-Wallis test revealed no significant differences in mean microleakage scores among all groups (p= 0.281).
Use of polyethylene fiber inserts and etch-and-rinse and self-etch adhesives had no effect on microleakage in class II resin composite restorations with gingival margins below the CEJ after 6- month water storage.
微渗漏是与树脂复合材料相关的最常见问题之一，尤其是在后牙修复体的牙龈边缘处。在复合修复体中插入纤维可减少复合材料的总量并有助于减少收缩。
本研究的目的是使用两种不同的粘结系统评估聚乙烯纤维插入物对II类复合修复体牙龈微渗漏的影响。
在本实验研究中，在60颗前磨牙上制备II类洞。牙龈底部位于釉牙骨质界下方1.0毫米处。每个洞的尺寸为颊舌径3毫米，轴向深度1.5毫米。根据粘结剂类型和纤维插入物将标本分为4组（n = 4）。使用单键粘结剂、Clearfill SE粘结剂和Filtek p60修复洞。在没有纤维插入物的组中，使用分层技术将复合材料适配到洞上。对于有纤维插入物的洞，将3毫米长的纤维插入物放置在复合增量上并固化。标本在37℃的蒸馏水中储存6个月。所有标本均进行3000次热循环。除修复边缘周围1毫米外的牙齿表面覆盖两层指甲油。将牙齿浸入2%碱性品红中24小时，然后冲洗并沿近远中方向切片。在立体显微镜（40倍）下测定微渗漏。数据采用Kruskal-Wallis检验和Mann-Whitney U检验进行统计学分析（p < 0.05）。
Kruskal-Wallis检验显示所有组之间的平均微渗漏评分无显著差异（p = 0.281）。
在储存6个月后，对于牙龈边缘位于釉牙骨质界下方的II类树脂复合修复体，使用聚乙烯纤维插入物以及酸蚀冲洗粘结剂和自酸蚀粘结剂对微渗漏没有影响。
