University of São Paulo - USP, Physics Institute of São Carlos - IFSC, Department of Physics and Materials Science, São Carlos, São Paulo 13566-590, Brazil; University of São Paulo State - UNESP, Araraquara School of Dentistry, Department of Restorative Dentistry, Araraquara, São Paulo 14801-903, Brazil.
University of São Paulo - USP, Physics Institute of São Carlos - IFSC, Department of Physics and Materials Science, São Carlos, São Paulo 13566-590, Brazil.
Mater Sci Eng C Mater Biol Appl. 2019 Mar;96:391-401. doi: 10.1016/j.msec.2018.10.063. Epub 2018 Oct 17.
The biofilm accumulation over the composite resin restorations can contribute to the formation of secondary caries. In this way, antibacterial restorative composite resins are highly desired. Then, the purpose of this study was to modify a composite resins using Ag doped ZnO nanoparticles (NPs), evaluate the antibacterial and mechanical properties of the modified composite resin. The ZnO/AgNPs were synthesized by two different routes, polymeric precursor and coprecipitation methods, and characterized by thermal decomposition, X-ray diffraction, specific surface area by N desorption/desorption and scanning electron microscopy (SEM). Antibacterial activity of composite resin specimens (4 mm in height and 2 mm in diameter; n = 15) modified by ZnO/Ag nanoparticles was performed against 7-days Streptococcus mutans biofilm. Colony forming units (CFU/mL) were used to evaluate the bacterial activity. Additionally, the morphology and the bacteria adherence area were analyzed by SEM images. Cylindrical specimens (6 mm in height and 4 mm in diameter; n = 20) of the composite resin containing ZnO/Ag NPs were prepared to perform compressive strength in a universal mechanical test machine, and the surface of fractured specimens was analyzed by EDX element mapping to verify NPs homogeneity. The normal distribution was confirmed and the two-way analysis of variance (ANOVA) and Tukey's test for pair comparison were performed. The nanospheres of ZnO/Ag lead to a better biofilm inhibition, than nanoplates. No difference on compressive strength was found for the composite resin modified by ZnO/Ag nanoplates. Based on these results, this material could be a good option as a new restorative material.
生物膜在复合树脂修复体上的积累会导致继发龋的形成。因此，人们非常希望使用具有抗菌性能的修复复合树脂。本研究的目的是通过掺杂银的氧化锌纳米粒子（NPs）对复合树脂进行改性，评估改性复合树脂的抗菌和机械性能。采用两种不同的方法，即聚合前驱体法和共沉淀法，合成了 ZnO/AgNPs，并通过热分解、X 射线衍射、N 吸附/解吸比表面积和扫描电子显微镜（SEM）进行了表征。通过 SEM 图像分析了复合树脂试件（高度为 4mm，直径为 2mm；n=15）的抗菌活性，对改性后的 ZnO/Ag 纳米复合树脂试件在 7 天内对变形链球菌生物膜的抑制作用。用菌落形成单位（CFU/mL）评估细菌活性。此外，还通过 SEM 图像分析了形貌和细菌黏附面积。制备含有 ZnO/Ag NPs 的复合树脂圆柱形试件（高度为 6mm，直径为 4mm；n=20），在万能试验机上进行抗压强度测试，并对断裂试件的表面进行 EDX 元素映射分析，以验证 NPs 的均匀性。通过双向方差分析（ANOVA）和 Tukey 检验进行配对比较，确认了正态分布。纳米球状 ZnO/Ag 对生物膜的抑制作用优于纳米片状 ZnO/Ag。改性复合树脂的抗压强度没有差异。基于这些结果，这种材料可能是一种很好的新型修复材料。
