College of Materials Science and Engineering, South China University of Technology, Guangzhou, China.
Department of Conservation Dentistry and Endodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China.
J Mech Behav Biomed Mater. 2022 Oct;134:105372. doi: 10.1016/j.jmbbm.2022.105372. Epub 2022 Jul 22.
With the aim to prepare Bis-GMA-free bulk-filled dental resin composite (DRC), Bis-GMA-free resin matrix was prepared by mixing Bis-EFMA with TEGDMA at two mass ratios (Bis-EFMA/TEGDMA = 50 wt/50 wt and 60 wt/40 wt), and the bulk-filled resin composites were then obtained by mixing resin matrix with silanated glass fillers at a mass ratio of 30 wt/70 wt. Bis-GMA based resin composites were used as control. Refractive indexes of resin matrixes were measured. Besides the depth of cure mentioned in ISO standard, double bond conversion (DC) and bottom/top Vickers hardness (VHN) ratio of resin composites were investigated to evaluate the curing depth. Physicochemical properties, such as flexural properties, volumetric shrinkage (VS), shrinkage stress (SS), water sorption (WS) and solubility (SL), and cytotoxicity of resin composites were tested and statistically analyzed (ANOVA, Tukey's, p = 0.05). The results showed that Bis-EFMA/TEGDMA resin matrixes had higher refractive indexes than Bis-GMA/TEGDMA resin matrixes. Viscosities of Bis-EFMA based DRCs were higher than Bis-GMA based DRCs. Bis-EFMA-based (50/50) DRC had comparable depth of cure, DC, and VHN as Bis-GMA-based (50/50) DRC (p > 0.05). Though Bis-EFMA/TEGDMA (60/40) had the highest refractive index in all resin matrix, the corresponding DRCs had the lowest depth of cure, DC, and bottom/top VHN ratio in all groups (p < 0.05). Replacing Bis-GMA with Bis-EFMA had no negative effect on flexural properties, WS and SL of DRCs, and could reduce VS and SS of DRCs. Results of CCK8 assay showed that all of DRCs had the same cytotoxicity (p > 0.05), and the thickness of sample had no influence on the cytotoxicity (p > 0.05). All the results indicated that Bis-EFMA could be used to replace Bis-GMA to prepare bulk-filled dental resin composites. According to the results of depth of cure, DC, and bottom/top VHN ratio, 50 wt/50 wt was more appropriate than 60 wt/40 wt as the mass ratio of Bis-EFMA and TEGDMA in the resin matrix for bulk-filled dental resin composites.
为了制备不含 Bis-GMA 的块状填充牙科树脂复合材料（DRC），通过将 Bis-EFMA 与 TEGDMA 以两种质量比（Bis-EFMA/TEGDMA=50wt/50wt 和 60wt/40wt）混合来制备不含 Bis-GMA 的树脂基质，然后将树脂基质与硅烷化玻璃填料以 30wt/70wt 的质量比混合得到块状填充树脂复合材料。使用基于 Bis-GMA 的树脂复合材料作为对照。测量树脂基质的折射率。除了 ISO 标准中提到的固化深度外，还研究了树脂复合材料的双键转化率（DC）和底部/顶部维氏硬度（VHN）比，以评估固化深度。测试并统计分析了树脂复合材料的物理化学性能，如弯曲性能、体积收缩（VS）、收缩应力（SS）、吸水率（WS）和溶解度（SL）以及细胞毒性（ANOVA，Tukey's，p=0.05）。结果表明，Bis-EFMA/TEGDMA 树脂基质的折射率高于 Bis-GMA/TEGDMA 树脂基质。基于 Bis-EFMA 的 DRC 的粘度高于基于 Bis-GMA 的 DRC。基于 Bis-EFMA（50/50）的 DRC 的固化深度、DC 和底部/顶部 VHN 与基于 Bis-GMA（50/50）的 DRC 相当（p>0.05）。尽管 Bis-EFMA/TEGDMA（60/40）在所有树脂基质中具有最高的折射率，但相应的 DRC 在所有组中具有最低的固化深度、DC 和底部/顶部 VHN 比（p<0.05）。用 Bis-EFMA 替代 Bis-GMA 对 DRC 的弯曲性能、WS 和 SL 没有负面影响，并且可以降低 DRC 的 VS 和 SS。CCK8 测定结果表明，所有 DRC 的细胞毒性相同（p>0.05），且样品厚度对细胞毒性无影响（p>0.05）。所有结果表明，Bis-EFMA 可用于替代 Bis-GMA 来制备块状填充牙科树脂复合材料。根据固化深度、DC 和底部/顶部 VHN 比的结果，在树脂基质中，Bis-EFMA 和 TEGDMA 的质量比为 50wt/50wt 比 60wt/40wt 更适合作为块状填充牙科树脂复合材料。
