STUDYING THE FLEXURAL STRENGTH OF SAMPLES OF MULTILAYER DENTAL CERAMICS BASED ON ZIRCONIUM DIOXIDE OF DOMESTIC AND CHINESE PRODUCTION AFTER TRADITIONAL AND HIGH-SPEED SINTERING

Abstract

A study on the strength of samples of multilayer dental ceramics based on zirconium dioxide of domestic and Chinese production with three-point bending is provided. Dentures made of dental ceramics based on zirconium dioxide are sintered in clinical practice using the traditional multi-hour or high-speed method. The traditional sintering mode requires a long time, careful control of temperature, heating speed and guarantees high strength and aesthetics during prosthetics. The high-speed mode sinters dental multilayer ceramics based on zirconium dioxide quickly, efficiently and provides a high-quality connection of all layers in a shorter time, however, it can lead to a higher probability of defects in the structure of the ceramic crown, such as cracks or bubbles between layers in the ceramic material. Materials and methods. The samples were produced by computer milling and sintered in the traditional 10-hour and high-speed sintering mode in 22 minutes. The obtained results were subjected to statistical processing, including the calculation of the arithmetic mean and the error of the average. The samples of the neck layer showed the greatest strength in three-point bending, but the intermediate layer turned out to be the weakest. According to the results, for Chinese samples, the high-speed sintering mode does not significantly change the strength of ceramic samples in comparison with traditional hours-long firing. The high-speed sintering mode of domestic samples reduces the strength during three-point bending. Conclusions. The study showed that samples of Chinese multilayer ceramics limit the indications for its use in prosthetics. Russian samples of multilayer dental ceramics based on zirconium dioxide exceed the performance of their foreign counterparts in terms of strength at three-point bending. The presented research is important for the development of effective methods of orthopedic treatment, as well as for optimizing the production process of dental ceramics.