Nanostructured Dental Composite Restorative Materials

描述（由申请人提供）：该项目的总体目标是开发一种具有低聚合应力的改进牙科复合材料，使用纳米粘土填料与BisGMA/TEGDEMA和/或环氧乙烷树脂组合，产生改进的机械性能。该项目是一个跨学科的努力，涉及三个独立的机构，UMKC，UMR和Mo-Sci公司。假设1（纳米粘土填料）纳米粘土填料的加入将改善BisGMA/TEGDMA（50：50）和UVR 6105/GY 281/PTHF（48：48：4）树脂体系的机械性能。具体目标：为了确定每种聚合物基质体系中纳米粘土填料的最佳表面改性和浓度（参见下面的假设2），以便选择将在混合填充的复合材料中提供最佳机械性能的粘合剂-纳米颗粒体系（参见下面的假设3）。假设2（应力降低聚合物）将螺原碳酸酯（TOSU）掺入两种不同的基质树脂中，双酚-A-二甲基丙烯酸缩水甘油酯（BisGMA）/二甲基丙烯酸三甘醇酯（TEGDMA）（50：50）和3，4-环氧环己基甲基-3，4-环氧环己基羧酸酯（UVR 6105）/双酚F的二缩水甘油醚（GY 281）/聚（四氢呋喃）（PTHF）（48：48：4），将降低纯树脂的聚合应力。 具体目的1确定将显著降低BisGMA/TEGDMA的聚合应力的最合适的螺原碳酸酯和最佳添加水平。将TOSU以0、1、5、10和20%的重量比添加到树脂中。具体目的2向UVR 6105/GY 281/PTHF（48：48：4）树脂中添加两种适当的TOSU。将按照具体目标1中规定的浓度添加TOSU。假设3（玻璃填料）将不透射线的REAS玻璃填料添加到基质树脂中，将产生具有比当前牙科复合材料更优越的上级机械性能的纳米混合复合材料。具体目标1选择与固化树脂的折射率相匹配的无碱稀土铝硅酸盐（REAS）玻璃。该玻璃将被加工成具有适当粒度分布（PSD）的玻璃粉末，其平均直径在0.05微米和5微米之间。具体目标2用适当的偶联剂（硅烷、钛酸酯或锆酸酯）对玻璃填料进行表面处理，使其与基体树脂结合。掺入的标准将包括表面处理、玻璃颗粒的PSD和玻璃颗粒在复合材料中的负载水平。具体目标3比较无碱稀土REAS玻璃改性复合材料与商业牙科复合材料的性能（机械、光学、化学）。成功完成拟议的研究将对牙科公共健康作出重大贡献，包括：（a）聚合应力显著降低的修复剂，这将增加修复体的耐久性和寿命;（B）固化深度增强的修复剂，可以批量放置，这将节省临床时间和资源;和（c）对含有纳米填料的甲基丙烯酸酯和环氧乙烷基聚合物材料的显著改进的理解。

DESCRIPTION (provided by applicant): The overall goal of this project is to develop an improved dental composite with low polymerization stress using nanoclay fillers producing improved mechanical properties combined with BisGMA/TEGDEMA and/or oxirane resins. This project is an interdisciplinary effort involving three separate institutions, UMKC, UMR, and Mo-Sci Company. Hypothesis 1 (nanoclay fillers) The addition of nanoclay fillers will improve the mechanical properties of the BisGMA/TEGDMA (50:50) and UVR6105/GY281/PTHF (48:48:4) resin systems. Specific Aim: To determine an optimum surface modification and concentration of nanoclay fillers in each polymer matrix system, (see hypothesis 2 below), in order to select a binder-nanoparticle system that will provide optimal mechanical properties in a hybrid filled composite (see hypothesis 3 below). Hypothesis 2 (stress-reducing polymer) The incorporation of a spiroorthocarbonate (TOSU) into two different matrix resins, Bisphenol-A-glycidyldimethacrylate (BisGMA)/ triethylene glycol dimethacrylate (TEGDMA) (50:50) and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclo-hexylcarboxylate (UVR6105)/Diglycidyl ether of Bisphenol F (GY281)/Poly(tetrahydrofuran) (PTHF) (48:48:4), will reduce the polymerization stress of the neat resins. Specific Aim 1 To determine the most appropriate spiroorthocarbonate and the optimal addition level that will significantly reduce the polymerization stress of BisGMA/TEGDMA. The TOSUs will be added to the resin at weight percents of 0, 1, 5, 10, and 20%. Specific Aim 2 To add two appropriate TOSUs to the UVR6105/GY281/PTHF (48:48:4) resin. The TOSUs will be added in concentrations as specified in Specific Aim 1. Hypothesis 3 (glass fillers) The addition of radio-opaque REAS glass fillers to the matrix resins, will produce a nano-hybrid composite with superior mechanical properties to current dental composites. Specific Aim 1 Select an appropriate alkali-free rare-earth aluminosilicate (REAS) glass that matches the refractive index of the cured resins. This glass will be processed into glass powder of appropriate particle size distribution (PSD) having average diameter between 0.05 and 5 microns. Specific Aim 2 Surface-treat the glass fillers with an appropriate coupling agent (either silane, or titanate or zirconate) will be incorporated into the matrix resin. Criteria for incorporation will include the surface treatment, PSD of the glass particles, and loading level of the glass particles into the composite. Specific aim 3 Compare properties (mechanical, optical, chemical) of alkali-free rare-earth REAS glass-modified composites to commercial dental composites. Successful completion of the proposed research will result in significant contributions to dental public health, including: (a) a restorative with significantly reduced polymerization stress which should increase the durability and longevity of the restoration; (b) a restorative with enhanced depth of cure that can be bulk placed which will save clinical time and resources; and (c) a significantly improved understanding of methacrylate and oxirane-based polymeric materials containing nano-fillers.