치과용 지르코니아 블록의 소결온도에 따른 기계적 특성과 색조변화

Abstract

Purpose: This study sought to identify changes in the mechanical characteristics and color of zirconia according to different sintering temperatures of the substance. Methods: This study processed some specimens of zirconia into those of 8 ㎜(H)×10 ㎜(W)×50 ㎜(L)±0.1 each, and sintered them at 1450~1600℃ on a 50℃-interval basis in order to examine how their mechanical characteristics and color are changed. Each specimen sintered using the spectral colorimetric apparatus (Easyshade, VITA, Germany) was observed for each of the color change by sintering temperature. Results: When those specimens were sintered at 1450~1600℃, they were 0% in absorption ratio and porosity, 20% in shrinkage ratio and 6.10g/㎤ in specific gravity. Absorption ration, porosity, shrinkage ratio and specific gravity all didn’t vary depending on the sintering temperature. The fracture strength of the specimens was highest or 1037㎫ at the sintering temperature of 1550℃ and a little lower or 989㎫ at that of 1600℃. No variation in L* value was found depending on the sintering temperature of the specimens, while c* value was highest at that of 1450℃. In addition, h* value was highest when the specimens was sintered at 1550℃. Conclusion: This study could determine how zirconia shows changes in mechanical characteristics and color in accordance with different temperatures of its sintering. It is necessary to supplement the physical data of colored transparent zirconia block which is expected to be widely used in clinical practice.