The effect of hot isostatic pressing and surface finish on the flexural strength of zirconia dental implants

摘要

Partially stabilized zirconi ceramics are an interesting group of materials for dental and orthopedic implant applications. One of their advantages over alumina ceramics is their higher fracture toughness. The strength and in general mechanical properties of ceramics depends to a large extent on the number and size of pores and flaws that arise during processing. Pressure-assisted sintering technique like hot isostatic pressing (HIP) is commonly thought to enhance the densification of the ceramics, resulting in improved strength. The purpose of this study was to determine the effect of the processing methods and surface finish on the flexural strength of yttria stabilized zirconia (3 molpercent Y-TZP). Four different levels of surface finish of Y-TZP were investigated under two different production conditions (HIP'ed and unHIP'ed). The results showed that hot isostatic pressing significantly increased flexural strength, whereas surface finish had no significant effect at the p<=0.05 level. A trend of surface finish affecting the strength, however, was observed within the hot isostatically pressed sample in comparison to cold isostatically pressed and sintered group, indicating that the effect of surface finish on strength becomes more important when the internal pores and flaws have been eliminated by hot isostatic pressing.