[Influence of La2O3 and Li2O on glass powder for infiltrating ZTA all-ceramic dental material formed by gel-casting].

PURPOSE: The influence of La2O3 and Li2O on glass powder was studied in this paper,which is to infiltrate ZTA all-ceramic dental material formed by gel-casting.The performance of different component was analyzed to optimize glass formula.METHODS: Six groups of glass powder were designed and prepared by conventional melt-quenching method.ZTA ceramic blocks were covered with glass paste,which were formed by gel-casting and sintered in 1200 ℃, then infiltrated in 1150℃ for twice to make glass/ZTA ceramic composites.By detecting differential thermal analysis and melting range of infiltration glass power,as well as flexural strength,linear shrinkage,SEM and EDS of glass/ZTA ceramic composites,the optimized glass group was determined out.Statistical analysis was performed using SPSS 13.0 software package by means of paired t test or one way ANOVA.RESULTS: The bending strength of group Li1 was(291.2±27.9) MPa, significantly higher than group Li2 and group La2(P0.05),and linear shrinkage of group Li1 was only(1.85±0.27)%.SEM and EDS showed glass of group Li1 can lubricate ZTA ceramics well,their structure was compact and had a few small pores.Intergranular fracture existed on cross surface as well as transgranular fracture.CONCLUSIONS: The results showed that Li1(30%La2O3-15%Al2O3-15%SiO2-15%B2O3-5%Li2O) glass infiltrated ZTA ceramic composite had the best capability.Glass/ZTA composite material can be prepared by gel-casting and infiltrating way,and this process is simple and economically suitable for general dental laboratory.