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目的:研究模拟口腔环境下牛牙釉质与二硅酸锂玻璃陶瓷的磨损特性。方法:将18个长8 mm、直径3 mm的二硅酸锂玻璃陶瓷圆柱作为上颌磨头,分别与下颌二硅酸锂玻璃陶瓷或牛牙釉质试件配副,每组9个样本,利用摩擦磨损试验机,在人工唾液、室温环境、10 N载荷、转速100 r/min、回转半径2.5 mm、匀速圆周运动的条件下进行54万次循环磨损实验。在整个磨损周期中选取10个循环节点,用三维形貌仪测量每个节点下颌试件的磨损高度损失量并绘制相应磨损曲线,扫描电镜观察相应磨损阶段对应的磨损面微观形貌。结果:各循环节点牛牙釉质的磨损量均大于二硅酸锂玻璃陶瓷的磨损量(P<0.05);实验循环周期内,牛牙釉质的磨损曲线呈现出“跑合期”、“稳定磨损期”、“剧烈磨损期”3个磨损阶段,而二硅酸锂玻璃陶瓷的磨损曲线呈现“跑合期”和“稳定磨损期”两个磨损阶段。2组的微观形貌也呈现出与磨损曲线相对应的阶段性动态衍化规律。结论:在模拟口腔环境下,牛牙釉质和二硅酸锂玻璃陶瓷的磨损行为均呈现出阶段性动态衍化规律;牛牙釉质的磨损量显著高于二硅酸锂的磨损量,提示应注意防止二硅酸锂玻璃陶瓷修复体对对颌天然牙的过度磨损。
OBJECTIVE: To study the wear characteristics of bovine enamel and lithium disilicate glass ceramic under simulated oral environment. METHODS: Eighteen 8-mm-long lithium disilicate glass ceramic cylinders with a length of 8 mm and a diameter of 3 mm were used as the maxillary grinding heads. They were matched with the mandibular lithium disilicate glass ceramics or the bovine enamel specimens respectively. Nine samples Friction and wear tester was used to perform 540,000 cycles of wear test under the condition of artificial saliva, room temperature environment, 10 N load, rotation speed 100 r / min, radius of gyration 2.5 mm and uniform circular motion. In the whole wear cycle, 10 cycles nodes were selected. The loss of wear height of the mandibular specimens at each node was measured with a three-dimensional topograph and the corresponding wear curves were drawn. The corresponding wear surface micro-morphology was observed by scanning electron microscope. Results: The wear volume of bovine enamel in each node was greater than that of lithium disilicate glass ceramic (P <0.05). The abrasion curve of bovine enamel showed “running-in period” within the experimental cycle, The wear period of “stable wear period” and “severe wear period” are three wear stages, while the wear curves of lithium disilicate glass ceramic show two wear stages of “running-in period” and “stable wear period”. The microstructures of the two groups also showed the regular dynamic derivatization rule corresponding to the wear curve. CONCLUSION: The wear behavior of bovine enamel and lithium disilicate glass ceramics shows a gradual dynamic derivation under simulated oral environment. The wear volume of bovine enamel is significantly higher than that of lithium disilicate, suggesting that Prevent excessive wear of natural teeth on the jaw of lithium disilicate glass ceramic restoration.