双重固化型牙本质黏结剂联合不同复合树脂修复牙本质窝洞的边缘封闭性研究

Marginal adaptation to dentin of different resin composites combined with dual-cured bonding system

关键词:  复合树脂  牙本质黏结  收缩裂隙

Key words:  resin composite  dentin bonding  contraction gap

摘要:

［目的］评价牙本质黏结剂的不同固化方式及不同复合树脂修复牙本质窝洞的边缘封闭性的影响。［方法］选用48颗成人离体磨牙，去除邻面牙釉质，在暴露出的牙本质平面上预备直径3 mm、深1.5 mm的柱状窝洞后随机分成8组，用光/化学双重固化型牙本质黏结剂Clearfil Liner Bond 2Σ（CLB2Σ, Kuraray Co.）按照单一化学固化及光/化学双重固化两种方式分别与4种桩核修复用复合树脂Clearfil Core （CC, Kuraray Co.），Palfique Core （PC, Tokuyama Co.），Clearfil DC Core （DC, Kuraray Co.）和 Unifil Core （UC, GC Co.）对各组窝洞进行充填。在高倍光学显微镜下测定各组用复合树脂修复的牙本质窝洞洞缘处的最大收缩裂隙值。［结果］无论牙本质黏结剂采用单一化学固化方式还是光/化学双重固化方式，4种复合树脂材料中均表现为UC组的收缩裂隙值最小，为0.095 ± 0.079（单一化学固化组）及0.087 ± 0.054（光/化学双重固化组），PC组最大，为0.292 ± 0.102（单一化学固化组）及0.286 ± 0.064（光/化学双重固化组）。而且除CC与DC 组之间差异无显著性意义（P>0.05）外，其余每两组间差异均有显著性意义（P<0.05）。但黏结剂不同固化方式之间差异没有显著性意义（P>0.05）。［结论］在本实验条件下，用4种复合树脂修复牙本质窝洞均未能避免窝洞洞缘收缩裂隙的产生，但UC的边缘封闭性最好；另外，牙本质黏结剂的固化方式未影响4种复合树脂修复牙本质窝洞的边缘封闭性。

Abstract:

［Objective］To evaluate the marginal adaptation of different resin composites to dentin using dual-cured dentin bonding agent by measuring the wall-to-wall polymerization contraction gap width in dentin cavity.［Methods］Cylindrical dentin cavity, approximately 3 mm in diameter and 1.5 mm in depth, prepared in the extracted human molar after eliminating enamel was restored by four resin composites, Clearfil Core (CC, Kuraray Co.), Palfique Core (PC, Tokuyama Co.), Clearfil DC Core (DC, Kuraray Co.) and Unifil Core (UC, GC Co.) and a dual-cured dentin bonding agent, Clearfil Liner Bond 2Σ (CLBK2Σ, Kuraray Co.) polymerized by autocuring or dual-curing. Resin composite used were only permitted a chemical polymerization in this study. After polymerization time of the manufacturer’s instructions, the maximum width of the marginal contraction gap was measured by use of a screw micrometer (Leitz, Wetzlar, Germany) mounted on the ocular lens of a light microscope (Orthoplane, Leitz, Wetzlar, Germany) at a magnification of 1024 . Six specimens were measured for each combination of variables, and the results were analyzed statistically with SPSS 11.0 at 5% significance level.［Results］None of the four resin composites could prevent the formation of a contraction gap of any mode of polymerization of dual-cured bonding agent, but UC showed better marginal adaptation (Chemical-cured: 0.095±0.079; Dual-cured: 0.087±0.054) than others. Significant difference were showed in marginal adaptation between four resin composites except for CC and DC (P<0.05), but there was no significant difference between different mode of polymerization of dual-cured bonding agent (P>0.05).［Conclusions］Within the limitations of this study, marginal adaptation was not effected by mode of polymerization of CLBK2Σ. Gap-free was not obtained in any of four resin composites, but the marginal adaptation of UC to dentin cavity wall was good.