Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkiye.
Med Oral Patol Oral Cir Bucal. 2011 Mar 1;16(2):e252-9. doi: 10.4317/medoral.16.e252.
The purpose of this study was to compare the effect of light curing distance on the cytotoxicity of five resin composites cured with three high-power light curing units.
Seven cylindrical discs of each material (Grandio®, Voco; Filtek™ Z250, 3M ESPE; Clearfil™ AP-X, Kuraray Co. Ltd.; Aelite™ LS, Bisco Inc. and Simile®, Pentron) were cured. For curing, soft-up mode of quartz-tungsten-halogen, exponential mode of light emitting diode for 20 s, and ramp-curing mode of plasma arc light curing units for 6 s were used. The curing tip distances were determined as 2 and 9 mm and controlled via the use of metal rings. After ageing the samples for 24 and 72 hours in Dulbecco's Modified Eagle Medium/Ham's F12 (DMEM/F12), cytotoxicity of the extracts to cultured fibroblasts (L 929) was measured by using MTT (tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. The degree of cytotoxicity for each sample was determined according to the reference value represented by the cells in a pure culture medium. Statistical significance was determined using multifactorial analysis of variance.
The type of resin composite (p <0.05), light curing unit (p <0.05), curing tip distance (p <0.05) and evaluation period factor (p <0.05) had statistically significant cytotoxic effects on L-929 mouse fibroblast cells. However, when the tested materials polymerized at both distances (2 mm and 9 mm) in both evaluation periods (24 h and 72 h), there was no significant difference in the mean CSR% values obtained when the quartz-tungsten-halogen, light emitting diode and plasma arc light curing units were used (p=0.184, F=1.448).
The results of this study suggest that the light curing units and resin composites should be harmonized to one another and the curing distance between the tip of the light curing unit and the restoration surface should be as close as possible in order to achieve maximal biocompatibility.
本研究旨在比较光固化距离对三种高功率光固化器固化的五种树脂复合材料细胞毒性的影响。
用每个材料（GC 伟瓦登特，Voco；Filtek™ Z250，3M ESPE；Clearfil™ AP-X，Kuraray Co. Ltd.；Aelite™ LS，Bisco Inc.和 Simile®，Pentron）制作七个圆柱形样本。使用石英钨卤素的软启动模式、发光二极管的指数模式 20 秒和等离子电弧光固化器的斜坡固化模式 6 秒进行固化。固化尖端距离分别设定为 2 和 9 毫米，并通过使用金属环进行控制。在 Dulbecco's Modified Eagle Medium/Ham's F12（DMEM/F12）中老化样本 24 和 72 小时后，使用 MTT（四唑盐 3-[4,5-二甲基噻唑-2-基]-2,5-二苯基四唑溴盐）测定提取物对培养成纤维细胞（L 929）的细胞毒性。根据纯培养基中细胞的参考值确定每个样本的细胞毒性程度。使用多因素方差分析确定统计学显著性。
树脂复合材料类型（p<0.05）、光固化器类型（p<0.05）、固化尖端距离（p<0.05）和评估期因素（p<0.05）对 L-929 小鼠成纤维细胞具有统计学显著的细胞毒性作用。然而，当在两种评估期（24 小时和 72 小时）在两种距离（2 毫米和 9 毫米）下聚合测试材料时，使用石英钨卤素、发光二极管和等离子电弧光固化器获得的平均 CSR%值没有显著差异（p=0.184，F=1.448）。
本研究结果表明，为了达到最大的生物相容性，光固化器和树脂复合材料应该相互协调，并且光固化器尖端和修复表面之间的固化距离应该尽可能接近。
