Effect of aging on the fracture resistance, marginal adaptation, and color stability of two different zirconia systems versus different preparation design

Abstract Objective The aim of this in-vitro study is to investigate the effect of aging on the fracture resistance, marginal adaptation, and color stability of two different zirconia systems in comparison to different preparation designs. Materials and methods Three stainless steel metal dies with different chamfer finish lines (0.5, 0.7, and 1.0 mm) represented a prepared mandibular first molar. A stainless steel metal die was duplicated using an epoxy resin material to produce identical master dies for standardized preparation. Fabrication procedures of crowns, including milling and sintering, were carried out for each ceramic brand; all dies were divided into two groups. Group Z: samples used were fabricated of 5Y-TZP and 3Y-TZP zirconia. Group K: samples used were fabricated from 5Y-TZP zirconia. All samples were tested for fracture resistance using a universal testing machine., Marginal gap between the dies and the crowns will be measured using a scanning electron microscope, and color stability will be evaluated using a color measurement device (spectrophotometer) before and after aging. Results It was found that ZirCAD Prime groups recorded statistically significantly higher gap mean value than Katana UTML groups after ageing. Regarding fracture resistance, the ZirCAD Prime groups recorded a statistically significantly higher mean fracture resistance value than the Katana UTML groups, both nonaged and aged. It was found that the difference between the material groups’ color stability mean values was statistically significant (ZirCAD Prime > Katana UTML). Conclusion ZirCAD Prime groups have a higher gap, higher fracture resistance, and more color stability than Katana UTML groups.