Properties Of Novel Dental Zirconia Material: A Pilot Study

PURPOSE:The purpose of this in vitro study was to evaluate and compare the translucency,flexural strength and shear bond strength of 3 types of zirconia materials.We chose products of both domestic and foreign brands.METHODS:1.Translucency test.Experimental group 1 was high-translucent zirconia:Lava^TM Plus（LP）,X-CERA SHT（XTH）,SHTC（SHTC）;experimental group 2 was ultra-translucent zirconia group:Lava^TM Esthetic（LE）,X-CERA TT（XTE）,Xuancai?AT（AT）;The control group was glass ceramic group.The translucency of each group was obtained by spectrophotometer,and the experimental results were analyzed by one-way ANOVA.2.Three-point flexural strength test.Five brands of zirconia were selected.High-translucent zirconia group:Lava^TM Plus（LP）,X-CERA SHT（XTH）,SHTC（SHTC）,Ideal Translucent（IT）,ST-Color（ST）;ultra-translucent zirconia group:Lava^TM Esthetic（LE）,X-CERA TT（XTE）,brilliant?AT（AT）,Ideal Esthetic（IE）,TT-LT（TT）.The three-point bending strength of each group was obtained by universal material testing machine according to the ISO6872 of the International Organization for Standardization（ISO）.Single factor analysis of variance（ANOVA）was used in the group and t-test was used between the groups.3.Micro-shear bond strength test.The experimental group ultra-translucent zirconia:X-CERA TT（XTE）,Xuancai?AT（AT）,Ideal Esthetic（IE）and TT-LT（TT）.Control group traditional zirconia:X-CERA ST（XT）,STC（STC）,Ideal Opaque（IO）,HT-Color（HT）.The micro-shear bond strength of each group was obtained by biomechanical analyzer,and single factor analysis of variance（ANOVA）was used in the group.T test was used in the groups.RESULTS:1.The translucency of glass ceramics（UP.CAD）with three kinds of thickness was significantly higher than that of other groups（P<0.01）.When the brand was the same,there was no significant difference between AT and SHTC of 0.5mm and 1.0mm,AT of 1.5mm was better than SHTC,P<0.01,LE of three thickness was better than LP.There was no significant difference between XTE and XTH of 0.5mm and 1.5mm,but XTE of 1.0mm was better than XTH（P<0.01）.The thickness of 0.5mm:SHTC,XTE,AT,LE were the best in each group;the thickness of 1.0mm:XTH,XTE were the best in each group,and the thickness of 1.5mm:XTH,XTE,LP were the best in each group（P<0.01）.2.When the brand was the same,the three-point bending strength of high-translucent zirconia was significantly higher than that of ultra-translucent zirconia（P<0.01）.When the type of zirconia was the same,XTH and XTE were the best in each group（P<0.01）.3.The micro-shear bonding strength of the same brand of ultra-translucent zirconia was significantly higher than that of traditional zirconia（P<0.01）.In traditional zirconia,STC was the best,HT was the second,IO was the lowest,AT and XTE were the best,TT was the second,IE was the lowest in ultra-translucent zirconia（P<0.01）.CONCLUSIONS:1.The translucency of glass ceramics with three kinds of thickness was better than that of new zirconia;the translucency of ultra-translucent zirconia was higher than that of high-translucent type;the difference of translucency of two new types of zirconia with the same brand was related to the thickness.2.When the brand was the same,the three-point bending strength of high-translucent zirconia was higher than that of ultra-translucent zirconia,and the three-point bending strength of ultra-translucent zirconia used in the experiment is more than 300 MPA.There were differences among brands.3.The micro-shear bonding strength of the same brand of ultra-transparent zirconia was higher than that of traditional zirconia,and there were differences among brands.