不同厚度和不同透明度铸瓷对树脂黏结剂固化效率的影响

Impact of cast-ceramic thickness and translucency on curing efficiency of dual-cured resin cement

目的研究不同厚度和不同透明度铸瓷对双固化树脂黏结剂固化效率的影响。方法选用4种不同透明度(高度透明HTA2、低度透明LTA2、中度不透明MO1、高度不透明HO1)的IPSe.max全瓷,制备成直径为6 mm,厚度分别为0.5、1、2、3、4 mm的圆片,共计20个。二极管(LED)光固化灯作为固化光源,VariolinkⅡ作为实验中的双固化树脂黏结剂,根据光照过程中有无铸瓷作为中介分为实验组和空白组。利用傅里叶红外光谱仪检测树脂黏结剂的双键转换率,并通过显微硬度仪记录固化后树脂的表面努氏硬度值。结果在同一透明度下,VariolinkⅡ树脂黏结剂表面努氏硬度值除HTA2和LTA2的1.0 mm与2.0 mm之间无显著性差异外(P>0.05),其余不同厚度组之间均存在显著性差异(P<0.05),且随着瓷片厚度的增加努氏硬度值呈降低趋势;在相同厚度下,HTA2和LTA2的树脂黏结剂表面努氏硬度值显著高于HO1和MO1(P<0.05),而HTA2与LTA2之间及HO1与MO1之间的努氏硬度值无显著性差异(P>0.05)。不同厚度和不同透明度铸瓷下VariolinkⅡ树脂黏结剂双键转换率均有显著性差异(P<0.05),且随铸瓷透明度降低及厚度增加呈降低趋势。树脂黏结剂的表面努氏硬度值和双键转换率除了IPSe.max HTA2组外,其余实验组均显著低于空白组(P<0.05)。结论双固化树脂黏结剂的固化效率受铸瓷厚度和透明度影响,且随其厚度增加及透明度降低固化效率降低。

Objective To determine the effect of the thickness and translucency of cast-ceramic on the curing efficiency of dual-cured resin cement.Methods Ceramic restorations（IPSe.max） with different translucencies,including high translucency（HTA2）,low translucency（LTA2）,medium opacity（MO1）,and high opacity（HO1）,were made into wafers at 6.0 mm in diameter and at 0.5,1,2,3 and 4 mm in thickness respectively（n=20）.The experimental group had the ceramic restorations positioned between the dual-cured resin cement（Variolink Ⅱ） and light source during polymerization.In the control group there was no ceramic restoration,and light curing was performed using light-emitting diodes（LED） as light source.The degree of conversion was evaluated using Fourier transform infrared（FT-IR） spectrometer,and the Knoop hardness test was performed on the cement layer.Results The degree of conversion and the hardness of dual-cured resin cement were decreased with the increase of thickness and the decrease of translucency（P0.05）,and in dual-cured control group they were the highest（except 0.5 mm groups of HTA2）.At the same translucency,the hardness showed statistical difference between different thickness groups except 1.0 mm groups and 2.0 mm groups of HTA2 and LTA2（P0.05）.For the wafers at the same thickness,the hardness of dual-cured resin cement presented no statistical difference between HTA2 and LTA2,between HO1 and MO1（P0.05）.However,the hardness of resin cement of HTA2 and LTA2 was significantly higher than that of HO1 and MO1（P0.05）.Conclusion Ceramic thickness and translucency have great influence on the hardness of dual-cured resin cement,and the curing efficiency is decreased with the increase of thickness and decrease of translucency.