ВЛИЯНИЕ СКОРОСТНОГО ОБЖИГА КЕРАМИЧЕСКОГО МАТЕРИАЛА НА ОСНОВЕ ДИОКСИДА ЦИРКОНИЯ ZICERAM T ОТЕЧЕСТВЕННОГО ПРОИЗ-ВОДСТВА НА ПОКАЗАТЕЛИ ПРОЧНОСТИ И ЦВЕТА

Abstract

Zirconia dentures are gradually becoming a widespread type of dental prosthetics. The production of zirconia blanks for dentistry has been launched in our country. In recent years, the possibility of high-speed sintering of zirconia dentures has been well studied, which makes it possible to reduce the manufacturing process of dental restorations by four to five times. Zirconia ceramics compositions and high-speed sintering furnaces are being improved, sintering protocols are being optimized. In this paper, we reported about the influence of high-speed firing protocols on important material`s characteristic, such as three-point bend flexural strength and color parameters at ten different heating modes, differing by heating rates, final temperature and holding time during high-speed heat treatment of ceramic material. Accord-ing to the results of bending strength tests, samples obtained with a total time of high-speed firing from 20 to 60 minutes have similar values, more than 300 MPa. In accordance with the ISO 6872 standard, such flexural strength is sufficient for fabrication of single crowns in both the anterior and posterior groups of teeth. A study on the laboratory spectrophotometer (Spectron M) in the CIELab system, showed a multidirectional change in color characteristics at different heating rates and sintering temperatures. An increase in the value of zirconia sam-ples from domestic blanks "Ziceram T" produced by St. Petersburg firm "Zircon Ceramics" was established with a sufficient confidence grade. The shortened firing time leads to an in-crease in the value of the samples, which associate with a lower translucency.