DEVELOPMENT OF NEW DENTAL COMPOSITE FORMULATIONS

本研究的长期目标是发展牙科复合材料 其对技术不太敏感，更容易形成湿牙结构， 具有降低的固化收缩和吸水性。 复合材料具有 与现有替代材料相比的几个优点：直接 技术、美学外观和对牙齿结构的粘附。 甚至 因此，剩余的问题限制了它们在后牙中的增加使用， 牙科汞合金仍在四分之三的国家使用， 所有的装饰。 两个主要的问题是牙齿中的应力， 固化收缩，以及将当前材料与 湿度在安置，这需要使用苛刻的， 不受欢迎的临床程序。 解决这些问题的紧迫性在于 牙科汞合金（唯一的替代品） 直接材料），由于汞的危害，可能会被禁止。 本研究提出了制备和评价系列复合材料 基于新合成的基质单体的材料。 这项工作是 基于现有材料的问题是 这主要是由于需要控制稀释剂单体的量 基质粘度低，因此，使用基质单体时， 粘度将导致改进的性能。 最近的试点工作， 实验室证实了这一假设。 修改 将制备传统的BIS-GMA单体，以及两个系列的 单体，其中中心-C（CH 3）2-被包含以下的基团替代： 磷或氟。 在每个系列中，将制备三种单体。 一种具有BIS-GMA的侧基-OH基团特征，另一种具有BIS-GMA的侧基-OH基团特征， -OH被-H和-CH 3替代。 合成方案和条件将是 调节以避免氢键和低聚，从而最小化 粘度 当纯单体的粘度超过 由于目前未固化的基质材料的特性，它将被稀释， 根据需要与TEGDM混合以产生标准粘度。 每种材料将 作为单体、作为未填充的聚合物和作为 混合复合材料。 将测试单体的粘度、润湿性、 吸水性和固化收缩。 的聚合物和 将测试复合材料的吸水性、吸水能力和 唾液，以及一系列物理和机械性能。

The long range goal of this study is the development of dental composites which are less technique sensitive, wet tooth structure more readily, and have reduced curing shrinkage and water sorption. Composites have several advantages over available alternative materials: direct technique, esthetic appearance, and adhesion to tooth structure. Even so, remaining problems limit their increased use in posterior applications, where dental amalgams are still used in three-fourths of all restorations. Two major problems are stresses in the tooth created by uncompensated curing shrinkage, and the necessity of isolating current materials from moisture during placement, which requires the use of demanding and unpopular clinical procedures. The urgency of solving these problems is increased by the possibility that dental amalgam, (the only alternative direct material), may be banned because of mercury hazards. This study proposes to prepare and evaluate the series of composite materials based upon newly synthesized matrix monomers. The work is based upon the hypothesis that the problems with current materials are largely due to the quantity of diluent monomers required to control matrix viscosity, and therefore that the use of matrix monomers of lower viscosity would lead to improved properties. Recent pilot work in this laboratory has confirmed this hypothesis. Modifications of the traditional BIS-GMA monomer will be prepared, as well as two series of monomers in which the central -C(CH3)2- is replaced by groups containing phosphorous or fluorine. In each series three monomers will be prepared. One with pendant -OH group characteristic of BIS-GMA, and others with the -OH replaced by -H and -CH3. Synthesis schemes and conditions will be adjusted to avoid hydrogen bonding and oligomerization, thus minimizing viscosity. Where the viscosity of the pure monomer exceeds the viscosity characteristic of present uncured matrix materials, it will be diluted with TEGDM as needed to produce a standard viscosity. Each material will be evaluated as a monomer, as the unfilled polymer and as the matrix of a hybrid composite. The monomers will be tested for viscosity, wetting ability, water sorption and curing shrinkage. The polymers and composites will be tested for water sorption, we ability by water and saliva, and a series of physical and mechanical properties.