Zhang Zhenzhen, Yi Yuanping, Wang Xuesong, Guo Jiawen, Li Ding, He Lin, Zhang Shaofeng
State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Changle Xi Road 145, Xi'an, Shaanxi, China.
Department of Stomatology, the Third Hospital of Xi'an, Shaanxi, China.
J Mech Behav Biomed Mater. 2017 Oct;74:111-117. doi: 10.1016/j.jmbbm.2017.05.035. Epub 2017 May 30.
This study evaluated the wear performance and wear mechanisms of four dental glass-ceramics, based on the microstructure and mechanical properties in the progressive wear process.
Bar (N = 40, n = 10) and disk (N = 32, n = 8) specimens were prepared from (A) lithium disilicate glass-ceramic (LD), (B) leucite reinforced glass-ceramic (LEU), (C) feldspathic glass-ceramic (FEL), and (D) fluorapatite glass-ceramic (FLU). The bar specimens were tested for three-point flexural strength, hardness, fracture toughness and elastic modulus. The disk specimens paired with steatite antagonists were tested in a pin-on-disk tribometer with 10N up to 1000,000 wear cycles. The wear analysis of glass-ceramics was performed using a 3D profilometer after every 200,000 wear cycles. Wear loss of steatite antagonists was calculated by measuring the weight and density using sensitive balance and Archimedes' method. Wear morphologies and microstructures were analyzed by scanning electron microscopy (SEM). The crystalline phase compositions were determined using X-ray diffraction (XRD). One-way analysis of variance (ANOVA) was used to analyze the data. Multiple pair-wise comparison of means was performed by Tukey's post-hoc test.
LD showed the highest fracture toughness, flexural strength, elastic modulus and crystallinity, followed by LEU and FEL, and FLU showed the lowest. However, the hardness of LD was lower than all the other three types of ceramics. For steatite antagonists, LD produced the least wear loss of antagonist, followed by LEU and FEL, and FLU had the most wear loss. For glass-ceramic materials, LD exhibited similar wear loss as LEU, but more than FLU and FEL did. Moreover, fracture occurred on the wear surface of FLU.
In the progressive wear process, veneering porcelains showed better wear resistance but fluorapatite veneering porcelains appeared fracture surface. Monolithic lithium disilicate glass-ceramics with higher mechanical properties showed more wear loss, however, they did not fracture and produced less wear loss of antagonists.
本研究基于四种牙科玻璃陶瓷在渐进磨损过程中的微观结构和力学性能，评估其磨损性能和磨损机制。
制备了条形（N = 40，n = 10）和圆盘形（N = 32，n = 8）试样，材料分别为（A）二硅酸锂玻璃陶瓷（LD）、（B）白榴石增强玻璃陶瓷（LEU）、（C）长石质玻璃陶瓷（FEL）和（D）氟磷灰石玻璃陶瓷（FLU）。对条形试样进行三点弯曲强度、硬度、断裂韧性和弹性模量测试。将圆盘试样与滑石质对偶体配对，在销盘摩擦磨损试验机上以10N载荷进行高达1000000次的磨损循环试验。每隔200000次磨损循环后，使用三维轮廓仪对玻璃陶瓷进行磨损分析。通过使用精密天平并采用阿基米德法测量重量和密度来计算滑石质对偶体的磨损损失。通过扫描电子显微镜（SEM）分析磨损形貌和微观结构。使用X射线衍射（XRD）确定晶相组成。采用单因素方差分析（ANOVA）对数据进行分析。通过Tukey事后检验进行多个均值的两两比较。
LD的断裂韧性、弯曲强度、弹性模量和结晶度最高，其次是LEU和FEL，而FLU最低。然而，LD的硬度低于其他三种陶瓷。对于滑石质对偶体，LD产生的对偶体磨损损失最小，其次是LEU和FEL，FLU的磨损损失最大。对于玻璃陶瓷材料，LD的磨损损失与LEU相似，但大于FLU和FEL。此外，FLU的磨损表面出现了断裂。
在渐进磨损过程中，贴面瓷表现出较好的耐磨性，但氟磷灰石贴面瓷出现了断裂表面。具有较高力学性能的整体式二硅酸锂玻璃陶瓷磨损损失较大，然而，它们没有发生断裂，并且对偶体的磨损损失较小。
