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，结合BisGMA/TEGDEMA和/或氧烷树脂，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UVR6105/GY281/PTHF（48:48:4）树脂体系的力学性能。具体目标：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（见下面的假设2），以便选择一种粘合剂-纳米颗粒体系，该体系将在混合填充复合材料中提供最佳的机械性能（见下面的假设3）。假设2（降低应力的聚合物）将螺型正碳酸酯（TOSU）掺入两种不同的基体树脂，双酚a -缩水甘油酯二甲基丙烯酸酯(BisGMA)/三乙二醇二甲基丙烯酸酯（TEGDMA）（50:50）和3,4-环氧环己基甲基-3,4-环氧环己基羧酸酯(UVR6105)/双酚F二缩水甘油醚(GY281)/聚四氢呋喃（PTHF）（48:48:4），将降低聚合应力。确定可显著降低BisGMA/TEGDMA聚合应力的最合适的螺原碳酸酯和最佳添加量。将TOSUs以0,1,5,10和20%的重量百分比添加到树脂中。在UVR6105/GY281/PTHF（48:48:4）树脂中添加两种合适的tosu。TOSUs将按特定目标1中规定的浓度添加。假设3（玻璃填充物）在基体树脂中加入放射性不透明的REAS玻璃填充物，将产生一种纳米混合复合材料，其机械性能优于目前的牙科复合材料。1选择与固化树脂折射率相匹配的无碱稀土铝硅酸盐（REAS）玻璃。这种玻璃将被加工成平均直径在0.05到5微米之间的适当粒径分布（PSD）的玻璃粉末。用适当的偶联剂（硅烷、钛酸盐或锆酸盐）对玻璃填料进行表面处理，将其掺入基体树脂中。掺入标准将包括表面处理，玻璃颗粒的PSD，以及玻璃颗粒进入复合材料的加载水平。将无碱稀土REAS玻璃改性复合材料与商用牙科复合材料的力学、光学、化学性能进行比较。成功完成拟议的研究将对牙科公共卫生作出重大贡献，包括：(a)一种聚合应力显著降低的修复体，这将增加修复体的耐久性和寿命；(b)具有增强固化深度的修复体，可以大量放置，从而节省临床时间和资源；(c)显著提高了对含有纳米填料的甲基丙烯酸酯和氧烷基聚合物材料的理解。

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.