Effects of sintering holding time on the microstructure and mechanical properties of translucent zirconia

Abstract

Background: With the great improvements in CAD/CAM technology, zirconiabased CAD/CAM ceramic is now widely used in dentistry. The CAD/CAM zirconia block offers the more efficient way to fabricate dental prostheses. However, the effects of sintering conditions and concomitant microstructure of zirconia-based materials (ZrO2) remain unclear. This study investigated the effects of varying the holding times on microstructure and mechanical properties of three different translucent zirconia materials. The objective of this study was to investigate the effects of holding time during sintering on the flexural strength, microhardness, grain dimension/shape, and translucency of three full-contour zirconia materials. The alternative hypothesis was that zirconia specimens sintered with a longer holding time would have influences on 1) flexural strength; 2) microhardness; 3) grain dimension/size under SEM; and 4) translucency compared with specimens sintered with the recommended heating schedule.