新型齿科多色系二硅酸锂玻璃陶瓷材料体系的构建及相关机理研究

Lithium disilicate glass ceramics have become the focus in the field of modern esthetical materials research for dental application, because these materials combine the advantage of both glass and ceramic. However, when using lithium disilicate glass ceramic in clinical practice, the critical problems which need to be resolved are: the coloring mechanism of lithium disilicate glass ceramics is not clear, and there is also a lack of colored glass ceramics system to well match the color characteristic of natural teeth. Therefore, the aesthetic properties of lithium disilicate glass ceramics need to be improved. In the previous research, we have developed a novel lithium disilicate glass ceramic which showed ideal strength and suitable translucency characteristics. In the present project, we aim to design and construct a novel polychromatic lithium disilicate glass ceramic system. In order to resolve the key science problems in the field of coloring research, we will conduct the program by considering colorant, base glass and crystalline treatment at an entire object to investigate the influence of adding colorant on the crystal dynamics, microstructure, crystalline composition and properties of lithium disilicate glass ceramic. Coloring mechanism will be clarified based on these results. Then, we will design different BP neural networks to fit the nonlinear relationship between the color parameter of final ceramc and the coloring oxide concentration, with the object to construct new strategy in coloring research. Following the guiding of optimized BP neural network, a polychromatic colored lithium disilicate glass ceramic system is to be developed to fulfill clinical requirements in color matching. Moreover, a systematical evaluation of the properties of these colored glass ceramics will be conducted including mechanical properties, resistent to aging treatments, and biocompatibility, with the aim to promote the clinical application of these new materials as soon as possible. The completion of the project will be the innovations in color matching theory and practice of dental glass ceramic, which show great potential prospect in future practice. The new polychromatic lithium disilicate glass ceramic will also play a positive role in improving the quality of dental aesthetic restoration .

二硅酸锂玻璃陶瓷因兼具玻璃和陶瓷的特性，具有实现力学性能和美学性能有机结合的潜在优势，已成为当前牙科修复材料的研究热点。然而，目前应用于美学修复实践亟待解决的瓶颈问题是：二硅酸锂玻璃陶瓷的颜色调控规律及机理尚不明确，缺乏能够满足与天然牙齿颜色匹配的材料体系。本项目在前期研究的基础上，提出设计和构建多色系齿科二硅酸锂玻璃陶瓷材料体系，针对颜色调控的关键科学问题，拟通过系统分析锆基着色剂的原料配比、晶化处理工艺等因素对玻璃陶瓷晶相组成、显微结构、理化性能及颜色特征的影响机制，阐明二硅酸锂玻璃陶瓷着色规律及机理；设计基于BP神经网络的颜色调控技术路线，通过优化BP神经网络结构拟合着色剂浓度与玻璃陶瓷颜色间的非线性映射关系，构建能够满足临床配色需求的多色系二硅酸锂玻璃陶瓷材料体系，并进行理化性能及生物安全性的系统评价。本项目的完成将是对牙科玻璃陶瓷颜色调控理论与实践的创新，具有理想的应用前景。

随着人们生活水平和审美意识的不断提高，以改善美学效果为主要目的的修复需求与日俱增。二硅酸锂玻璃陶瓷因其兼顾高强度和半透明特征，已成为当前美学修复的重要发展方向之一。本项目在自主研发的二硅酸锂玻璃陶瓷的基础上，系统分析锆基氧化物着色剂对二硅酸锂玻璃陶瓷的析晶、微观结构、颜色、半透性及反射光谱关系的影响，利用添加不同比例的CeO2和TiO2，制备具有不同半透性特征的二硅酸锂玻璃陶瓷；建立了基于BP人工神经网络的计算机配色研究路线，筛选出3-30-30-30-3网络结构进行实验二硅酸锂玻璃陶瓷配色，并验证其配色精度。研究表明采用BP人工神经网络配色能够实现实验二硅酸锂玻璃陶瓷的计算机制备，其配色精度优于三刺激值和全光谱匹配法，并且能获得与靶目标相近的颜色；对目前牙科用二硅酸锂玻璃陶瓷和实验玻璃陶瓷的弯曲强度和半透明性进行比较分析，结果显示实验二硅酸锂玻璃陶瓷具有优秀的半透性特征和力学强度；分析了不同表面处理对实验玻璃陶瓷表面粗糙度、粘接性能及细菌粘附性能的影响，结果显示抛光能够获得更加光滑的表面，与上釉相比，抛光处理可以使材料表面变形链球菌粘附量更少；喷砂+酸蚀处理可以明显提高瓷与树脂粘接剪切强度，在临床实际应用时建议采用酸蚀（20s）+偶联剂的表面处理方法；并分析了修复体厚度对二硅酸锂玻璃陶瓷冠抗碎裂性能的影响，当增加陶瓷厚度时，抗断裂性能提高，推荐1.0～1.2mm的厚度作为临床修复体的制作要求，为实验二硅酸锂玻璃陶瓷的临床应用提供了实验室依据。本项目的完成是对牙科玻璃陶瓷配色理论与实践的创新，研发的材料具有理想的机械强度和美学特征，能够满足临床美学修复需求，具有理想的应用前景，对我国美学修复效果的提高有积极的推动作用。