Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
Department of Physics, Faculty of Science, State University of São Paulo, Bauru, SP, Brazil.
Dent Mater. 2020 Dec;36(12):1544-1556. doi: 10.1016/j.dental.2020.09.013. Epub 2020 Oct 2.
To evaluate the influence of the addition of functionalized and non-functionalized TiO nanostructures on properties of a resin composite.
TiO nanostructures were synthesized and functionalized, using 3-(aminopropyl)triethoxysilane (APTMS) and 3-(trimethoxysilyl)propyl methacrylate (TSMPM). Characterizations were performed with XRD, EDS, TEM, and TGA. Resin composites containing Bis-GMA/TEGDMA, CQ, DABE, and barium-aluminum silicate glass were produced according to TiO nanostructure (nanotube or nanoparticle), concentration (0.3 or 0.9 wt%), and functionalization (APTMS or TSMPM). The resin composite without nanostructures was used as control. The amount of fillers was kept constant at 78.3 wt% for all materials. The degree of conversion (DC - at 0 h and 24 h), maximum polymerization rate (Rp), and Knoop microhardness (KHN before and after ethanol softening) were evaluated. Data were analyzed with two-way ANOVA with repeated measures and Tukey's HSD (α = 0.05).
TGA results demonstrated that functionalizations were effective for both nanostructures. For DC, resin composites, time and interaction effect were significant (p < 0.001). Higher DC was found for 0.3-wt%-functionalized-nanotubes at 24 h. For nanoparticles, only 0.9-wt%-non-functionalized and 0.3-wt%-APTMS-functionalized showed DC similar to the control and all other groups showed higher DC (p < 0.05). Rp was higher for 0.3-wt%-APTMS-nanotubes, which corresponded to higher DC after 24 h. The lowest Rp occurred for 0.9-wt%-TSMPM-nanotubes, which showed smaller DC at 0 h. For KHN, resin composites, ethanol softening and interaction effect were significant (p < 0.001). KHN decreased after ethanol softening all groups, except for 0.3-wt%-TSMPM-nanotubes, 0.9-wt%-TSMPM-nanotubes, and 0.3-wt%-non-functionalized-nanoparticles.
The resin with 0.3-wt%-TSMPM-nanotubes showed higher DC after 24 h, while being the most stable material after the ethanol softening.
The addition of functionalized TiO nanostructures in resin-based materials may improve the properties of the material.
评估功能性和非功能性 TiO2 纳米结构的添加对树脂复合材料性能的影响。
使用 3-(氨丙基)三乙氧基硅烷（APTMS）和 3-(三甲氧基硅基)丙基甲基丙烯酸酯（TSMPM）合成并功能化 TiO2 纳米结构。通过 XRD、EDS、TEM 和 TGA 进行表征。根据 TiO2 纳米结构（纳米管或纳米颗粒）、浓度（0.3 或 0.9wt%）和功能化（APTMS 或 TSMPM）制备含有 Bis-GMA/TEGDMA、CQ、DABE 和钡铝硅酸盐玻璃的树脂复合材料。不含纳米结构的树脂复合材料用作对照。所有材料的填料量均保持在 78.3wt%不变。评估转化率（DC-在 0 小时和 24 小时）、最大聚合速率（Rp）和克努普硬度（KHN 在乙醇软化前后）。使用双向方差分析和 Tukey 的 HSD（α=0.05）进行数据分析。
TGA 结果表明两种纳米结构的功能化均有效。对于 DC，树脂复合材料、时间和相互作用效应具有统计学意义（p<0.001）。24 小时时，发现 0.3wt%-功能化纳米管的 DC 更高。对于纳米颗粒，只有 0.9wt%-非功能化和 0.3wt%-APTMS 功能化的纳米颗粒与对照的 DC 相似，所有其他组的 DC 均更高（p<0.05）。24 小时后，0.3wt%-APTMS-纳米管的 Rp 更高。0.9wt%-TSMPM-纳米管的 Rp 最低，0 小时时的 DC 最小。对于 KHN，树脂复合材料、乙醇软化和相互作用效应具有统计学意义（p<0.001）。除 0.3wt%-TSMPM-纳米管、0.9wt%-TSMPM-纳米管和 0.3wt%-非功能化纳米颗粒外，所有组在乙醇软化后 KHN 均降低。
24 小时后，含 0.3wt%-TSMPM-纳米管的树脂显示出更高的 DC，而在乙醇软化后是最稳定的材料。
在基于树脂的材料中添加功能化 TiO2 纳米结构可以改善材料的性能。
