项目名称： 正畸热压膜材料口腔环境老化机制研究

项目编号： No.81470779

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 白玉兴

作者单位： 首都医科大学

项目金额： 73万元

中文摘要： 无托槽隐形矫治是近年来兴起的新型牙齿矫正技术，因其舒适、美观和椅旁时间少等优点已在临床上广泛应用。然而，临床应用发现，牙齿的移动往往滞后于预期矫治效果，多数病例仍需要在矫治过程中修正预定方案和增加步骤，甚至还需转为固定矫治。研究表明，隐形矫治器的临床使用效果与其材料（热压膜材料）的老化密切相关。因此，研究热压膜材料在口腔环境下的老化机制是临床上正确选择和使用隐形矫治器、提高治疗效果的关键，对开发新型、高效的正畸专用热压膜材料也具有重要的科学意义。本项目拟研究在模拟口腔环境中常用正畸热压膜材料的老化过程，综合电子显微学、光谱学和热力学等技术，分析水、热等物理化学因素对材料的成分、分子结构、表面形貌、机械性能、流变性能和玻璃态转化温度等的影响；同时，对比研究隐形矫治器在口腔中使用前后的物理、化学和力学性能变化，从而认识材料在口腔环境中的老化机制。

中文关键词： 隐形矫治技术；热压膜材料；口腔环境；老化机制；电子显微学

英文摘要： Esthetic alternatives to conventional fixed appliances are often requested as a result of increased interest in adult orthodontics. Thanks to the development of computer-aided design/computer-aided manufacturing techniques in the past two decades, transparent thermoplastic materials have been precisely designed and fabricated into a series of clear, removable tooth aligners for orthodontics. This orthodontic treatment modality, the most renowned of which is Invisalign, becomes more and more attractive than traditional fixed appliances because it offers a number of advantages including less pain, virtually transparent and relatively short chairtime. Despite being increasingly accepted by patients, the mechanical properties and tooth-moving process of orthodontic thermplastic appliances remains unclear and most patients need mid-course correction, refinement or change directly to fixed appliances. It is surmised that the lackluster treatment results are due to the aging process of thermoplastic materials under oral environment. Since mechanical properties are decided by micro-structure of these materials, it is crucial to look into the aging mechanism, i.e. the change of mechanical properties and micro-structure during aging process, and then develop thermoplastic materials of higher performance. However, relative research on mechanical properties and aging mechanism of orthodontic thermoplastic materials remains sparse. Therefore, our study is looking into the chagne of composition, micro-structure, surface topography, mechanical and physical properties before and after thermal treatment and immersion in 37℃ artificial saliva, and trying to uncover the aging mechanisms. Futhermore, we study the composition, micro-structure, surface topography of aligners both before and after clinical application, and try to learn the aging effect of oral environment on thermoplastic materials.

英文关键词： Invisible orthodontics;Thermoplastic materials;Oral environment;Aging mechanism;Electron microscopy