Soh G, Sidhu S K
Department of Restorative Dentistry, National University of Singapore.
J Oral Rehabil. 1994 Jul;21(4):411-7. doi: 10.1111/j.1365-2842.1994.tb01155.x.
The presence of the smear layer prevents direct contact between dentine and a dentine adhesive. The use of agents to remove the smear layer theoretically should improve the bonding of composite resins to dentine. This study examined the effect of smear layer removal on the effectiveness of a dentine bonding agent in reducing marginal contraction gaps. The agent used for smear layer removal in this study was ethylenediamine tetra-acetic acid (EDTA). Eighty cavities measuring 2 mm in diameter and 1.5 mm in depth were prepared in dentine and randomly assigned to two equal groups. The control group was restored with Prisma Universal Bond 2 Adhesive and Prisma Fil Resin. The experimental group was similarly restored after pretreatment of dentine with 0.5% EDTA for 60 s. All specimens were thermocycled and the marginal contraction gaps were assessed using a Nikon Measurescope. The mean contraction gap was expressed as a percentage of the cavity diameter. Results showed that the experimental group registered smaller contraction gaps (mean: 0.021%) than the control group (mean: 0.027%). No penetration of material into dentine was observed. Pretreatment with EDTA did not significantly improve the effectiveness of the dentine bonding agent used in terms of reduction of marginal contraction gaps.
玷污层的存在会阻碍牙本质与牙本质黏结剂之间的直接接触。理论上，使用去除玷污层的试剂应能改善复合树脂与牙本质的黏结。本研究考察了去除玷污层对牙本质黏结剂减少边缘收缩间隙效果的影响。本研究中用于去除玷污层的试剂是乙二胺四乙酸（EDTA）。在牙本质中制备了80个直径2 mm、深度1.5 mm的洞，并随机分为两组。对照组用Prisma Universal Bond 2黏结剂和Prisma Fil树脂修复。实验组在牙本质用0.5% EDTA预处理60秒后进行类似修复。所有标本进行热循环处理，并用尼康测量显微镜评估边缘收缩间隙。平均收缩间隙以洞直径的百分比表示。结果显示，实验组的收缩间隙（平均值：0.021%）比对照组（平均值：0.027%）小。未观察到材料渗入牙本质。就减少边缘收缩间隙而言，用EDTA预处理并未显著提高所用牙本质黏结剂的效果。
