Ramic Bojana D, Premovic Milica T, Stojanac Igor L, Drobac Milan R, Petrovic Ljubomir M
Faculty of Medicine, University of Novi Sad, Department of Dentistry, Novi Sad, Serbia.
Am J Dent. 2018 Feb;31(1):7-12.
To verify the influence of placement and polymerization technique on the gap width between dentin and composite restoration.
Standardized cylindrical cavities (3 mm in diameter, 2 mm deep) with all margins in dentin were prepared on buccal and oral surfaces of 30 extracted human third molars. With regard to the different resin composite filling techniques used, the samples were randomly divided into three groups (n=20): bulk; incremental; pin. Each group was further subdivided into subgroups based on different light polymerization techniques): continuous (40 seconds); discontinuous (2 seconds of activation, followed by 10 seconds of dark interval, then light polymerization continued for 38 seconds). After finishing procedures, impressions were made using polyvinylsiloxane, and epoxy resin replicas were obtained and prepared for scanning electron microscopy. The percentage of the marginal gaps in relation to the whole margin was recorded and statistically analyzed (P)≤ 0.05).
Marginal adaptation of composite restorations placed into the dentin cavities using pin and discontinuously light polymerized presented significantly better results than other two tested groups polymerized in the same manner.
The proposed modified incremental placement technique with a transparent glass pin reduces marginal leakage at the interface between composite restoration and dentin; leakage which can jeopardize the longevity of the restoration.
验证放置方式和聚合技术对牙本质与复合树脂修复体之间间隙宽度的影响。
在30颗拔除的人类第三磨牙的颊面和舌面制备标准化圆柱形窝洞（直径3mm，深2mm），所有边缘均位于牙本质内。根据所使用的不同树脂复合材料填充技术，将样本随机分为三组（n = 20）：整块填充；分层填充；带钉填充。每组再根据不同的光聚合技术进一步细分为亚组：连续光照（40秒）；间断光照（激活2秒，随后黑暗间隔10秒，然后继续光聚合38秒）。完成操作后，使用聚乙烯基硅氧烷制取印模，获得环氧树脂复制品并制备用于扫描电子显微镜检查。记录边缘间隙相对于整个边缘的百分比并进行统计学分析（P≤0.05）。
使用带钉填充并间断光聚合放置在牙本质窝洞内的复合树脂修复体的边缘适应性，比以相同方式聚合的其他两个测试组表现出明显更好的结果。
所提出的采用透明玻璃钉的改良分层放置技术可减少复合树脂修复体与牙本质界面处的边缘渗漏；这种渗漏会危及修复体的使用寿命。
