Effects of speed sintering on multilayered monolithic zirconia

Abstract

Objectives: In dentistry, different products are being developed in order to shorten the chairside but the interactions between these materials needs further investigations. This study aims to investigate the two different short time sintering protocols on monolithic multilayered zirconia's surface roughness (SR), translucency parameter (TP), and contrast ratio (CR). Materials and Methods: 20 monolithic multilayer zirconia specimens were prepared with the dimension 10x10x1 mm and divided into two sintering groups (speed sintering group 30 min at 1510 0C, high speed sintering group 10 min 1580 0C) and SEM analyzed was performed. Surface roughness tests were performed by using profilometer and optical measurements were performed by using spectrophotometer. The data was statistically analyzed by using Wilcoxen test at the 0.05 probability level. Results: Surface roughness and contrast ratio among groups were not statistically different. In all parts of monolithic multilayered zirconia, the difference of TP between sintering groups were statistically significant (p < .05). No obvious grain size difference was detected according to the SEM images. Conclusions: High speed sintering parameters has promising effects on monolithic multilayered zirconia with combined acceptable optical properties. Because of their different content, different layers show different reactions in terms of contrast ratio and translucency parameters and these changes should be taken into account in treatment planning.