Influence of increment thickness on light transmission, degree of conversion and micro hardness of bulk fill composites
Influence of increment thickness on light transmission, degree of conversion and micro hardness of bulk fill composites
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DOI：
10.1007/s10266-015-0227-0
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发表时间：
2016-09-01
期刊：
影响因子：
2.5
通讯作者：
Lassila, Lippo
中科院分区：
文献类型：
--
作者：
Garoushi, Sufyan;Vallittu, Pekka;Lassila, Lippo
本研究通过树脂复合材料的不同增量厚度，评估了散装填充，常规和纤维增强树脂基复合材料（RBC）的透光率，单体转化率和表面显微硬度的特性。工作假设是蓝光通过不同种类的RBC的透射率存在差异，并且增量的厚度影响RBC的单体转化程度。评估了六个散装填充、三个传统纳米混合、一个短纤维增强和一个可流动的RBC。对于每种材料，考虑了四种不同的增量厚度（1、2、3和4 mm）（n = 5）。在顶部和底部开口的圆柱形特氟隆模具中制备试样，并通过施加固化单元固化40秒。在固化过程之后，用粒度为1200和4000的碳化硅纸研磨样品，然后在37 A摄氏度下干燥储存24小时。测量透光率、单体转化度、表面显微硬度，并使用ANOVA（p = 0.05）分析数据。不同类型、不同品牌的树脂复合材料的透光率存在差异。低粘度的散装填充和短纤维增强的红细胞呈现出更高的透光率相比，树脂复合材料的粘度更高。降低的光透射率和较低的表面显微硬度和DC %在底部侧的试样表明，需要更多的注意，以确保适当固化的树脂复合材料在深腔。
This study evaluated characteristics of light transmission, degree of monomer conversion and surface microhardness of bulk fill, conventional and fiber-reinforced resin based composites (RBCs) through different incremental thicknesses of resin composite. Working hypotheses was that there are differences in transmission of blue light through RBCs of different kinds and that the thickness of the increments influence the degree of monomer conversion of RBCs. Six bulk fill, three conventional nanohybrid, one short fiber reinforced and one flowable RBCs were evaluated. For each material, four different incremental thicknesses (1, 2, 3 and 4 mm) were considered (n = 5). The specimens were prepared in cylindrical Teflon molds that are open at the top and the bottom sides and cured for 40 s by applying the curing unit. After curing process, the specimens were ground with a silicon carbide paper with a grit size of 1200 and 4000, and then stored dry at 37 A degrees C for 24 h. Light transmission, degree of monomer conversion, surface microhardness were measured and data were analyzed using ANOVA (p = 0.05). There were differences in light transmission of resin composites of various types and brands. Low-viscous bulk fill and short fiber-reinforced RBCs presented higher light transmission compared to resin composites of higher viscosity. Reduced light transmission and lower surface microhardness and DC % at bottom side of the specimen suggests that more attention needs to be paid to ensure proper curing of the resin composite in deep cavities.