Nassar Hani, Chu Tien-Min, Platt Jeffrey
King Abdulaziz University, School of Dentistry, Department of Operative Dentistry, Jeddah, Saudi Arabia.
Indiana University, School of Dentistry, Department of Restorative Dentistry, Indianapolis, IN, USA.
Braz Oral Res. 2016 May 20;30(1). doi: 10.1590/1807-3107BOR-2016.vol30.0066.
The use of a free-radical polymerization inhibitor, butylhydroxytoluene (BHT), and a common photo-initiator, camphorquinone (CQ), to reduce polymerization stress in dental composite was investigated in this study. Samples were prepared by mixing Bis-GMA, UDMA, and TEGDMA at a 1:1:1 ratio (wt%), and silanized borosilicate glass fillers at 70 wt% were added to form the composite. Sixteen groups of resin composite were prepared using combinations of four CQ (0.1%, 0.5%, 1.0%, and 1.5%) and four BHT (0.0%, 0.5%, 1.0%, and 1.5%) concentrations. For each group, six properties were tested, including flexural strength (FS), flexural modulus (FM), degree of conversion (DC), contraction stress (CS), stress rate, and gel point (GP). The effects of CQ and BHT combinations on each of these properties were evaluated using two-way analysis of variance (ANOVA) and Fisher's Protected Least Significant Differences test at the 5% significance level. Groups with low CQ and BHT showed moderate values for FS, FM, and CS with a 70% DC. Increasing the BHT concentration caused a decrease in CS and DC with an increase in GP values. Increasing the CQ content led to a steady increase in values for FS and FM. High CQ and BHT combinations showed the most promising values for mechanical properties with low stress values.
本研究考察了使用自由基聚合抑制剂丁基羟基甲苯（BHT）和常见光引发剂樟脑醌（CQ）来降低牙科复合材料聚合应力的情况。通过将双酚A双甲基丙烯酸缩水甘油酯（Bis-GMA）、二甲基丙烯酸氨基甲酸酯（UDMA）和三乙二醇二甲基丙烯酸酯（TEGDMA）按1:1:1比例（重量百分比）混合，并添加70重量百分比的硅烷化硼硅酸盐玻璃填料来制备样品，从而形成复合材料。使用四种CQ浓度（0.1%、0.5%、1.0%和1.5%）与四种BHT浓度（0.0%、0.5%、1.0%和1.5%）的组合制备了16组树脂复合材料。对于每组，测试了六项性能，包括弯曲强度（FS）、弯曲模量（FM）、转化率（DC）、收缩应力（CS）、应力速率和凝胶点（GP）。使用双向方差分析（ANOVA）和Fisher保护最小显著差异检验在5%显著性水平下评估CQ和BHT组合对这些性能的影响。低CQ和BHT的组显示出中等的FS、FM和CS值，DC为70%。增加BHT浓度会导致CS和DC降低，同时GP值增加。增加CQ含量会导致FS和FM值稳步上升。高CQ和BHT组合显示出最有前景的机械性能值，且应力值较低。
