颜色及光照射条件对复合树脂核材料聚合的影响

The effects of shade and light irradiation on the polymerization of composite resin core materials

目的:评估材料颜色和光照射条件对流动性双重固化复合树脂核材料聚合的影响。方法:将双重固化流动性复合树脂核材料(牙本质色和白色,Para Core)注满单端开口的长方体不透光硅橡胶模具中,将光固化灯紧贴开口端以1 000 mW/cm^2持续照射20 s或以3 200 mW/cm^2持续照射6 s获得4组试件(n=5)。试件避光保存1 h后,测量试件纵断面距光源1、2、3mm深度的努氏显微硬度。试件继续避光保存24 h后,重复上述测量。采用单因素方差分析对数据进行统计学分析。结果:4组试件随测量深度的增加试件的硬度值显著降低。光照后24 h,牙本质色试件每个测量深度的硬度值在1 000 mW/cm^2×20 s和3 200 mW/cm^2×6 s条件间无显著差异,但白色试件每个测量深度的1 000 mW/cm^2×20 s的硬度值要显著高于3 200 mW/cm^2×6 s的硬度值。结论:不同颜色的复合树脂核材料需要选择合适的光照射条件来获得最佳的聚合效果。

Objective： To evaluate the effects of shade and light irradiation condition on the polymerization of composite resin core ma- terial. Methods： The lightproof silicon rubber cuboid mold with one end open were stringed and filled by dualcured flowable compos- ite resin core material with the shade of dentine and white（Paracore） respectively, then the open end of mold was irradiated directly by a light unit at 1 000 mW/cm2 x20 s and 3 200 mW/cm2 x6 s respectively. And all specimens of 4 groups（n =5） were stored in the light-proof box. 1 h and 24 h after irradiation, Knoop microhardness was measured along the vertical surfaces of the specimens at the depth of 1,2 and 3 mm respectively. Data were analyzed by One-way ANOVA. Results： At all light irradiation conditions, the hard- ness of all specimens decreased with the increase of measurement depth. 24 h after irradiation, the hardness of dentine shade specimens at each measurement depth showed no difference between 1 000 mW/cm2×20 s and 3 200 mW/cm2 × 6 s irradiation, while the white shade specimens irradiated by 1 000 mW/cm2 × 20 s showed higher hardness than those by 3 200 mW/cm2 × 6 s. Conclusion： To ob- tain sufficient polymerization of composite core material with different shade optimal light irradiation condition should be selected.