Development of high performance, caries-inhibiting dental nano-materials

描述（由申请人提供）：继发性龋齿和修复体断裂是更换现有牙齿修复体的最常见原因。在美国，替代牙科占所有手术工作的70%，每年花费50亿美元。在初步研究中，首次合成了磷酸钙（Ca-PO 4）和氟化钙（CaF 2）的纳米颗粒，并将其掺入牙科树脂中。本研究的目标是：（1）开发新一代的抗应力、防龋纳米复合材料;（2）确定纳米颗粒尺寸和成分的影响，以及美学玻璃共填料增强;（3）设计具有超过电流释放剂的牙齿龋齿抑制能力，以及与电流应力承受相匹配的长期机械耐久性和磨损的纳米复合材料，非释放复合材料;（4）建立纳米复合材料的加工方法和结构-性能关系。AIM 1将测试以下假设：（i）减小纳米颗粒尺寸将显著增加释放，使其远高于含有传统Ca-PO 4颗粒的对照复合材料;（ii）玻璃增强将改善纳米复合材料的强度、韧性和磨损，以匹配商业应力承受、非释放复合材料，并且比当前释放的复合材料好2-3倍。AIM 2将测试以下假设：（i）纳米复合材料的氟化物释放与CaF 2纳米颗粒尺寸成反比，与CaF 2体积分数成正比;（ii）纳米复合材料的强度和韧性比树脂改性玻璃离子对照高2-3倍，磨损深度为对照的1/3。目的3将测试以下假设：（i）牙齿龋齿抑制取决于纳米颗粒的尺寸和组成;（ii）具有更高机械性能的纳米复合材料可以比当前释放的龋齿剂更有效地预防牙齿龋齿。目的4将测试以下假设：（i）对水老化和热循环的机械响应将取决于纳米颗粒的尺寸和组成;（ii）Ca、PO 4和F释放超过当前释放替代剂的纳米复合材料在水老化和热循环2年后将具有与商业应力承受、非释放复合材料相匹配的机械性能;（iii）在水老化/热循环之后，纳米复合材料将超过对照的长期离子释放。预期成果是：（1）新一代承受应力的纳米复合材料，释放高水平的抗蛀牙剂，抑制牙齿龋齿;（2）通过克服二次龋齿和修复失败这两个主要问题，对牙科产生重大影响;（3）新型纳米复合材料加工方法、结构-性能关系和模型，其可应用于牙和骨组织工程，其中应力承受和控制释放能力都是重要的。 项目叙述：该项目利用我们实验室首次合成的新型纳米颗粒，旨在开发新一代的抗应力、抑制牙齿龋齿的纳米复合材料，以克服继发性龋齿，这是替代现有牙釉质的主要原因。替代牙科占所有手术工作的70%，仅在美国每年就花费50亿美元。此外，该项目将建立新的纳米复合材料加工方法，结构-性能关系和模型，这可以有利于牙科和骨组织工程，其中承重和控释能力都很重要。

DESCRIPTION (provided by applicant): Secondary caries and restoration fracture are the most frequent reasons for replacement of existing tooth restorations. Replacement dentistry accounts for 70% of all operative work and costs $5 billion/year in the US. In preliminary studies, nanoparticles of calcium phosphates (Ca-PO4) and calcium fluoride (CaF2) were synthesized for the first time and incorporated into dental resins. The objectives of the proposed research are to: (1) develop a new generation of stress-bearing, caries-inhibiting nancomposites; (2) determine the effects of nanoparticle sizes and compositions, and esthetic glass co-filler reinforcement; (3) design nanocomposites with tooth caries-inhibition capability exceeding current releasing restoratives, and long-term mechanical durability and wear that match current stress-bearing, non-releasing composite; and (4) establish nanocomposite processing methods and structure-performance relationships. AIM 1 will test the hypotheses that: (i) Decreasing the nanoparticle size will significantly increase the release to be much higher than a control composite containing traditional Ca-PO4 particles; (ii) Glass reinforcement will improve the nanocomposite strength, toughness and wear to match commercial stress-bearing, non-releasing composite, and to be 2-3 fold better than current releasing restoratives. AIM 2 will test the hypotheses that: (i) Fluoride release from nanocomposite is inversely proportional to CaF2 nanoparticle size, and is proportional to CaF2 volume fraction; (ii) Nanocomposites will have strength and toughness 2-3 fold greater than a resin-modified glass ionomer control, and wear depth 1/3 that of the control. AIM 3 will test the hypotheses that: (i) Tooth caries inhibition depends on nanoparticle size and composition; (ii) Nanocomposites, with much higher mechanical properties, can prevent tooth caries much more effectively than current releasing restoratives. AIM 4 will test the hypotheses that: (i) Mechanical response to water-aging and thermal-cycling will depend on nanoparticle size and composition; (ii) Nanocomposites, with Ca, PO4 and F release exceeding current releasing restoratives, will possess mechanical properties that match commercial stress-bearing, non-releasing composite, after 2 years of water-aging and thermal cycling; (iii) After water-aging/thermal cycling, nanocomposites will exceed the long-term ion release of the controls. The expected outcomes are: (1) A new generation of stress-bearing nanocomposites with release of high levels of cavity-fighting agents to inhibit tooth caries; (2) Significant impact on dentistry by overcoming the two major problems: secondary caries, and restoration failure; (3) Novel nanocomposite processing methods, structure-property relationships and models, that can be applied to dental and bone tissue engineering where stress-bearing and controlled-release capabilities are both important. PROJECT NARRATIVE: This project, utilizing novel nanoparticles synthesized in our laboratory for the first time, seeks to develop a new generation of stress-bearing, tooth caries-inhibiting nancomposites to overcome secondary caries, which is the major reason for replacement of existing restorations. Replacement dentistry accounts for 70% of all operative work and costs $5 billion/year in the US alone. Furthermore, this project will establish novel nanocomposite processing methods, structure-property relationships and models, which can benefit dental and bone tissue engineering where load-bearing and controlled-release capabilities are both important.