Effect Of Multiple Sintering On The Marginal Adaptation Of Crowns Fabricated By Rapidly Crystallized Zirconia And Case Report

Objective: To study the effect of multiple sintering on the marginal adaptation of crowns fabricated by rapidly crystallized zirconia.Methods: The research objects are the IRZCs fabricated by Y-TZP ceramic materials with two different crystallization methods.All IRZCs are divided into the conventional group and the speed group.Each group has 10 IRZCs(20 in total).After the IRZCs are crystallized,they are located in the abutment.Use a stereomicroscope equipped with DS2 M digital CCD graphics processing and E-Max professional measurement software to measure the AMD values of IRZCs and abutments with eight equally spaced marking points.After the measurement,the two sets of IRZCs are placed on the Dental ceramic furnace for glazing process.The AMD values is measured again according to the same method.After the glazing and measurement processes are repeated three times,the AMD values of the two sets of IRZCs after crystallization and one to three sintering are obtained,performing repeated independent sample t-tests on measurement data,and one-way analysis of variance.The data is analyzed statistically to compare whether the AMD values of the conventional group and the speed group are different,and the effect of multiple sintering on the marginal adaptation of IRZCs fabricated by rapidly crystallized Y-TZP ceramic materials.Results: The results of statistical analysis of the difference between the AMD values of the conventional group and the speed group: After crystallization and after the third sintering,there is no significant difference in the mean AMD values of the two groups of IRZCs,P >0.05;After the first sintering and the second sintering,the mean AMD values of speed group are smaller than that of the conventional group,and the difference is statistically significant.The P > 0.05(P values are 0.0326 and 0.0396,respectively).The data of the two groups are analyzed by one-way analysis of variance within the group.The results showed that there is no significant difference in the AMD values of the IRZCs between the two groups after multiple sintering,and the P >0.05.Conclusions: In this study,IRZCs fabricated by two different crystallization methods of Y-TZP ceramic materials are used as the research object.The AMD values of the sample after different sintering times are obtained by using a stereomicroscope,and the measurement data is statistically analyzed.Under the conditions of this study,we could obtaine the following conclusions:(1)The AMD values of IRZCs fabricated by the two kinds of Y-TZP crystallized by different methods are smaller than the clinically acceptable marginal adaptation reported in previous studies,and the marginal adaptation of the rapid crystallized YTZP ceramic material In Coris TZIC is slightly better than that of another conventional crystallized Y-TZP ceramic material.(2)It is not found that multiple sintering has a significant effect on the marginal adaptation of the IRZCs fabricated by rapidly crystallized Y-TZP ceramic material.