Wear Performance of Lithium Disilicate Glass-ceramic after Grinding and Polishing Treatments
Objective To study the effects of grinding and polishing on the dynamic wear behavior of lithium disilicate glass ceramics in simulated oral environment,and provide reference for oral clinical operation.Methods Sixteen lithium disilicate glass ceramic cylinders with a diameter of 3 mm and a length of 8 mm and lithium disilicate glass ceramic discs with a diameter of 20 mm and a thickness of 4 mm were prepared,and the upper and lower test pieces were randomly divided into two groups.one group was polished to 600 mesh as the grinding group,and the other group was polished to 2 000 mesh with polishing cloth with synthetic leather polishing pad as polishing group,each group of 8 samples,in friction and wear testing machine The friction pair was composed and 500,000 cycles of wear test were carried out under artificial saliva,room temperature environment,20 N load,rotation speed 100 r/min,radius of gyration 2.5 mm,and uniform circular motion.10 loop nodes were selected in the whole wear cycle.The wear height loss of each node disc specimen was measured by three-dimensional shape analyzer and the corresponding wear curve was drawn.Then the scanning surface was used to observe the wear surface corresponding to the wear phase.Results During the whole wear process,the measured values of each node showed that the wear amount of the lithium disilicate glass ceramics in the grinding group was larger than that in the polishing group lithium disilicate glass ceramics(P＜0.05).The wear curve shows two wear stages:"running period"and"stable wear period".The"running period"of the grinding group is better than the"running period"of the polishing group,the time to enter the"stable wear period"is later than the polishing group.The microscopic morphology of the two sets of specimens also showed a two-stage law corresponding to the wear curve.Conclusion In the simulated oral environment,the wear of lithium disilicate glass ceramics in the grinding group is significantly higher than that in the polishing group,suggesting that the clinical should pay attention to the adequate polishing after the prosthesis is worn to reduce wear and prolong the life of the prosthesis.
国家科技期刊平台
NSTL
万方数据
