光固化修复材料的吸水性对人工间隙的影响

Water Sorption of a Compomer and a Composite on Artificial Gap Reduction.

目的 :本实验比较了两种光固化修复材料复合体 /复合树脂在 12周浸水实验后人工间隙的变化。方法 :选择 40个深 5mm ,内径 5 .5mm的玻璃圆柱体作为人工洞形 ,其内表面的 1/ 2进行喷砂 ,酸蚀 ,硅烷化 ,涂布一层牙本质粘接剂Primer&BondNT ,分别由光固化材料DyractAP(D)和SpectrumTPH(S)充填各 2 0个 ,这样在圆柱体的未粘接面形成人工间隙。每组中 10个样本浸泡在 37℃的去离子水中 (W) ,10个样本浸泡在 37℃的硅油 (O)中 ,通过光学显微镜放大 5 70倍测量 0 ,1,2 ,4,6 ,8,10 ,12周每个样本产生的最大间隙值 ,并进行统计分析 ,同时检测间隙减小的程度与储存时间的关系。结果 :统计分析得出不同时间测量的两种材料最大间隙值在浸水组有显著性差异 (P<0 .0 0 1) ,在浸油组却不存在 (P >0 .0 5 ) ,进一步分析D -W组在第六周后和S -W组在第四周后就无显著性差异 ;线性回归分析显示D -W和S -W这两组中的间隙宽度随时间以指数形式减少 ,从回归线的斜率可得出D -W组的间隙减少的速率比S -W组快 4.6倍。结论 :人工间隙的减小是由两种光固化材料的吸水性决定 ,而且在DyractAP组中间隙减小得更多、更快。

Objective:This study compared the effect of water sorption on the extent of marginal gap reduction in a compomer (Dyract D,Dentsply) and a composite(Spectrum TPH, Dentsply) over a 12-week storage period.Methods:Artificial gaps were created in 40 glass cylinders, each 5mm deep and with an internal diameter of 5.5mm.Half of the internal bonding surface of each cylinder was sandblasted, silanised and coated with a dentine adhesive (Primer & Bond NT, Dentsply).Twenty partially bonded cylinders were incrementally filled with Dyract AP (D) and the rest with Spectrum TPH (S).For each material, 10 specimens were stored in deionised water (W), and 10 (control) in non-aqueous silicone fluid (O) at 37℃.The dimension of the same maximum gap created in each specimen was repeatedly measured at 0,1,2,4,6,8,10 and 12 weeks,using a light microscope under incident light at 570 magnification.Gap widths in each of the four groups (n=10) were statistically compared.Correlations between mean gap width reduction and storage time were also examined.Results:Friedman repeated measures ANOVA on ranks revealed significant differences (P<0.001) among the gap widths measured at different time intervals in groups D-W and S-W. No significant differences (P>0.05) were found in groups S-O and D-O. Multiple comparison tests indicated that no significant differences (P>0.05) were detectable beyond the sixth week in D-W and the fourth week in S-W. Linear regression analyses showed that mean gap widths decrease exponentially with time for D-W (r=0.97) and S-W(r=0.90).From the slopes of the regression lines, the rate of marginal gap reduction in D-W was 4.6 times faster than S-W.Conclusions:Marginal gap reduction in both the materials are directly attributed to water sorption and that the reduction is larger and more rapid in Dyract AP.