Department of Chemical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, 81746-73441, Iran.
Dent Mater. 2022 May;38(5):858-873. doi: 10.1016/j.dental.2022.04.004. Epub 2022 Apr 14.
The main aim of the current work was to develop the novel self-healing dental composites contained poly(methyl methacrylate) (PMMA) microcapsules. The effects of PMMA microcapsule content in self-healing performance and mechanical properties of dental composites including flexural strength, flexural modulus, and fracture toughness were discussed. The antibacterial activity and non-toxicity properties of optimum self-healing dental composites were also investigated.
Novel acrylic microcapsules were prepared using triethylene glycol dimethacrylate (TEGDMA) as healing agent and PMMA as microcapsule shell via solvent evaporation method. The silica nanoparticles with the mean size of 15-20 nm were treated by 3-methacryloxypropyltrimethoxysilane (MPS) to enhance their adhesion and dispersion within the acrylic matrix of composite. Acrylic microcapsules with mass fractions of 0%, 5%, 10%, and 15% were added into a mixture of acrylic resins and MPS-grafted SiO nanoparticles. The strength and elastic modulus of dental composites were measured by the flexural test. The single edge V-notched beam (SEVNB) method was applied to investigate fracture toughness (K) and healing efficiency. The results were then statistically analyzed using one-way analysis of variance (ANOVA) at the confidence level of 0.95.
Acrylic microcapsules were synthesized with the mean size around 30 µm and the core content of about 15 wt%. The grafting percentage of MPS surface modifier onto SiO nanoparticles was measured 3.2%. The incorporation of PMMA microcapsules into the dental composites had no significant effect on flexural properties. The self-healing dental composites also indicated the high efficient healing performance in the range of 78-121%. The self-healing dental composites also exhibited impressive antibacterial activity against Streptococcus mutans (S. mutans). The MTT assay also revealed that the incorporation of acrylic microcapsules in dental composites has no cytotoxicity effects. SIGNIfiCANCE: In the current study, for the first time, the self-healing dental nanocomposites contained acrylic microcapsules were prepared with excellent healing performance and antibacterial properties.
本研究的主要目的是开发新型自修复牙科复合材料，其中包含聚甲基丙烯酸甲酯（PMMA）微胶囊。讨论了 PMMA 微胶囊含量对自修复性能和牙科复合材料力学性能（包括弯曲强度、弯曲模量和断裂韧性）的影响。还研究了最佳自修复牙科复合材料的抗菌活性和无毒性能。
通过溶剂蒸发法，使用三甘醇二甲基丙烯酸酯（TEGDMA）作为愈合剂和 PMMA 作为微胶囊壳，制备新型丙烯酸微胶囊。用 3-甲基丙烯酰氧基丙基三甲氧基硅烷（MPS）处理平均粒径为 15-20nm 的二氧化硅纳米粒子，以增强其在复合树脂丙烯酸基质中的附着力和分散性。将质量分数为 0%、5%、10%和 15%的丙烯酸微胶囊加入到丙烯酸树脂和 MPS 接枝 SiO2纳米粒子的混合物中。通过弯曲试验测量牙科复合材料的强度和弹性模量。采用单边 V 型缺口梁（SEVNB）法研究断裂韧性（K）和愈合效率。结果采用置信水平为 0.95 的单因素方差分析（ANOVA）进行统计分析。
合成的丙烯酸微胶囊平均粒径约为 30μm，核含量约为 15wt%。表面改性剂 MPS 接枝到 SiO2纳米粒子上的接枝率为 3.2%。将 PMMA 微胶囊掺入牙科复合材料中对弯曲性能没有显著影响。自修复牙科复合材料也表现出高效的愈合性能，范围在 78-121%之间。自修复牙科复合材料对变形链球菌（S. mutans）也表现出显著的抗菌活性。MTT 试验还表明，将丙烯酸微胶囊掺入牙科复合材料中没有细胞毒性作用。
在本研究中，首次制备了具有优异修复性能和抗菌性能的含丙烯酸微胶囊的自修复牙科纳米复合材料。
