Nanostructured Dental Composite Restorative Materials

描述(申请人提供)：该项目的总体目标是开发一种低聚合应力的改进牙科复合材料，使用纳米粘土填料，结合双GMA/TEGDEMA和/或环氧乙烷树脂产生更好的机械性能。这个项目是一个跨学科的努力，涉及三个不同的机构，UMKC，UMR和Mo-Sci公司。假设1(纳米粘土填料)添加纳米粘土填料将改善双GMA/TEGDMA(50：50)和UVR6105/GY281/PTHF(48：48：4)树脂体系的力学性能。具体目的：确定每个聚合物基质体系中纳米粘土填料的最佳表面改性和浓度(见下文假设2)，以选择在混杂填充复合材料中提供最佳机械性能的粘结剂-纳米颗粒体系(见下文假设3)。假设2(减压聚合物)在两种不同的基质树脂--双酚-A-缩水甘油二甲基丙烯酸酯(双GMA)/三甘醇二甲基丙烯酸酯(TEGDMA)(50：50)和3，4-epoxycyclohexylmethyl-3，4-epoxycyclo-hexylcarboxylate(UVR6105)/双酚F二缩水甘油醚(GY281)/聚四氢呋喃(PTHF)(48：48：4)中加入螺环原碳酸酯(TOSU)，将降低NEAT树脂的聚合应力。具体目标1确定最合适的螺环原碳酸酯和显著降低双GMA/TEGDMA聚合应力的最佳加入量。将TOSU按重量百分比0、1、5、10和20%添加到树脂中。具体目标2向UVR6105/GY281/PTHF(48：48：4)树脂中添加两个适当的TOSU。TOSUS将按特定目标1中指定的浓度添加。假设3(玻璃填充物)在基质树脂中添加不透射线的REAS玻璃填充物，将产生具有优于当前牙科复合材料的机械性能的纳米混杂复合材料。具体目标1选择合适的无碱稀土硅酸铝(REAS)玻璃，与固化树脂的折射率相匹配。这种玻璃将被加工成平均直径在0.05至5微米之间的适当粒度分布(PSD)的玻璃粉。特定目标2-使用适当的偶联剂(硅烷、钛酸盐或锆酸盐)对玻璃填充物进行表面处理，将其加入基质树脂中。纳入标准将包括玻璃颗粒的表面处理、PSD和玻璃颗粒在复合材料中的装载量。具体目标3比较无碱稀土REAS玻璃改性复合材料与商用牙科复合材料的性能(力学、光学、化学)。成功完成拟议的研究将对牙科公众健康做出重大贡献，包括：(A)显著降低聚合应力的修复材料，这将增加修复的耐久性和寿命；(B)可批量放置的修复材料，其固化深度更高，将节省临床时间和资源；以及(C)显著提高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了解。

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.