Department of Chemistry, South Dakota School of Mines and Technology, Rapid City, SD 57701-3995, USA.
Dent Mater. 2012 Oct;28(10):1071-9. doi: 10.1016/j.dental.2012.06.007. Epub 2012 Jul 13.
To investigate the reinforcement of Bis-GMA/TEGDMA dental resins (without conventional glass filler) and the corresponding composites (with conventional glass filler) containing varied mass fractions of halloysite nanotubes (HNTs).
Three dispersion methods were studied to separate the silanized halloysite as individual HNTs and to uniformly distribute them into dental matrices. Photopolymerization induced volumetric shrinkage was measured by using a mercury dilatometer. Real time near infrared spectroscopy was adopted to study the degree of vinyl double bond conversion and the photopolymerization rate. Mechanical properties of the composites were tested by a universal mechanical testing machine. Analysis of variance (ANOVA) was used for the statistical analysis of the acquired data. Morphologies of halloysite/HNTs and representative fracture surfaces of the reinforced dental resins/composites were examined by SEM and TEM.
Impregnation of small mass fractions (e.g., 1% and 2.5%) of the silanized HNTs in Bis-GMA/TEGDMA dental resins/composites improved mechanical properties significantly; however; large mass fractions (e.g., 5%) of impregnation did not further improve the mechanical properties. The impregnation of HNTs into dental resins/composites could result in two opposite effects: the reinforcing effect due to the highly separated and uniformly distributed HNTs, and the weakening effect due to the formation of HNT agglomerates/particles.
Uniform distribution of a small amount of well-separated silanized HNTs into Bis-GMA/TEGDMA dental resins/composites could result in substantial improvements on mechanical properties.
研究 Bis-GMA/TEGDMA 牙科树脂（不含传统玻璃填料）和含有不同质量分数海泡石纳米管（HNTs）的相应复合材料（含传统玻璃填料）的增强作用。
研究了三种分散方法，以将硅烷化海泡石分离为单个 HNTs 并将其均匀分布到牙科基质中。通过使用汞膨胀计测量光聚合诱导的体积收缩。采用实时近红外光谱法研究乙烯基双键转化率和光聚合速率。通过万能试验机测试复合材料的力学性能。采用方差分析（ANOVA）对所获得数据进行统计分析。采用 SEM 和 TEM 观察海泡石/HNTs 的形态和增强牙科树脂/复合材料的代表性断裂表面。
将少量（例如 1%和 2.5%）硅烷化 HNTs 浸渍到 Bis-GMA/TEGDMA 牙科树脂/复合材料中可显著提高力学性能；然而，大量（例如 5%）浸渍并不能进一步提高力学性能。HNTs 浸渍到牙科树脂/复合材料中可能会产生两种相反的效果：由于高度分离和均匀分布的 HNTs 而产生的增强效果，以及由于 HNT 团聚体/颗粒的形成而产生的弱化效果。
将少量的、充分分离的硅烷化 HNTs 均匀分布到 Bis-GMA/TEGDMA 牙科树脂/复合材料中，可显著提高力学性能。
