Degree of Conversion and Color Stability of two Dual-Cure Resin Cements under two Thicknesses of Cubic Ultra-Translucent Zirconia.

Abstract

Cubic zirconia is widely used now for variable resin bonded restoration, Due to its high translucency, type of cement affects color and final shade of these restorations especially dual cure resin cements. No doubt that degree of polymerization of cement to be used affect its physical properties. So, the objective of this study was experimenting the color stability of two dual cure resin cements and their degree of conversion under two thicknesses of cubic zirconia; in order to achieve maximum natural tooth looking restoration as we can. Material and methods: for color stability test, twenty-eight samples of ultra-translucent zirconia (BruxZir, Glidewell company, shade A1) were divided into two groups according to the thickness (n=14) 0,5mm and 1mm. Samples were further divided into subgroups according to the cement type (n=7), two dual cure resin cement (NX3, Kerr company Translucent shade; Resicem, Shofu company Translucent shade). Nano-hybrid composite (Herculite XRV Ultra, Kerr company, Italy shade A2) used as a substrate for cementation. For degree of conversion test, Twenty- four cement samples were divided into two groups according to the cement type (n=14), samples were further divided into subgroups according to ceramic thickness (n=7).