SYNTHESIS OF MOLECULAR COMPOSITES NOVEL DENTAL MATERIALS

已开发了三大类牙科材料并用于 牙科实践：(1)无机/陶瓷材料(例如银汞合金和 硅酸盐水泥)、(2)有机聚合物(例如聚丙烯酸酯树脂)和(3) 填充物与聚合物按一定比例混合的聚合物复合材料 宏观层面。所有这些材料，尽管在某些方面取得了成功 其在牙科应用中存在许多固有的缺陷。 提出了一种新型的牙科材料，它具有共价性和 将有机聚合物均匀地结合到无机网络中 分子水平通过一种新出现的溶胶凝胶法。这些分子 复合材料将会有量身定做的硬度组合 无机玻璃和有机聚合物的韧性。因为有机的 无机组分共价键合，均匀分布在 这些新材料，将不会有接口问题，因为在 传统的牙科复合材料。 在本方案中，选择了聚丙烯酸酯-二氧化硅-二氧化钛体系作为典型体系 为利用油井的优势进行初步研究的实例 已确定的受控分子量和分子量的临床应用 所需的端基，如-Si(OR)3，它在溶胶-凝胶中是活性的 反应，将通过基团转移聚合的方法合成 1983年在杜邦发明的。四种类型的遥控聚合物将是 由一个、两个、三个/四个或多个反应性-Si(OR)3基团合成。 遥控聚合物随后将被引入硅的混合物中 和/或钛四醇氧化物在b水解和交联化之后 (致密化)导致了新的分子复合材料。 这类新材料将进行表征和测试。取决于 无机和聚合物组分的性质和比例，它 应具有优异的物理和化学性能，如硬度， 韧性、对牙齿结构的粘附性、耐磨性和耐磨性， 稳定性等方面优于现有的牙科材料。

Three major classes of dental materials have been developed and used in dental practice: (1) inorganic/ceramic materials (e.g. amalgams and silicate cements), (2) organic polymers (e.g. polyacrylate resins) and (3) polymer composite materials in which fillers are mixed with a polymer at a macroscopic level. All of these materials, though succeeded in certain extent, have many inherent deficiencies in their dental applications. A novel class of dental materials is proposed, which covalently and uniformly incorporates organic polymers into an inorganic network at the molecular levels via a newly emerged sol-gel method. These molecular composite materials would have tailored combinations of the hardness of inorganic glasses and the toughness of organic polymers. Since the organic and inorganic components are covalently bonded and uniformly distributed in these new materials, there would be no interface problems as exist in the conventional dental composites. In this proposal, polyacrylates-SiO2-TiO2 systems are selected as typical examples for the initial studies with the view of taking advantage of well- established clinical applications of controlled molecular weights and desirable end groups such as -Si(OR)3, which is reactive in sol-gel reactions, will be synthesized by group-transfer polymerization method invented at Du Pont in 1983. Four types of telechelic polymers will be synthesized with one, two, three/four, or more reactive-Si(OR)3 groups. The telechelic polymers will then be introduced into the mixture of silicon and/or titanium tetraalkoxides followed b hydrolysis and crosslinking (densification) leading to the new molecular composite materials. This new class of materials will be characterized and tested. Depending on the nature and the ratio of the inorganic to the polymeric components, it should be superior in physical and chemical properties such as hardness, toughness, adhesion to tooth structure, resistance to wear and abrasion, stability, etc. over the existing dental materials.