Effect of Different Sintering Procedures on Marginal and Internal Fit, Color, and Fracture Load of Monolithic Zirconia Fixed Partial Prosthesis.

Abstract

The aim of this in vitro study is to investigate the effects of different sintering procedures on the fit, color parameters, and fracture load of monolithic fixed partial prosthesis. Metal model was scanned and fixed partial prosthesis was designed. Groups were created by fabricating fixed partial prosthesis by using four different sinterization procedures (Prettau-Standard (PST), Prettau-Slow (PSL), Ice-Speed (IS), Ice-Standard (IST), n=10). PST-PSL (Group P, N=20) and IS-IST (Group I, N=20) were colored with different coloring liquids. The marginal and internal fit were measured using the silicone replica method. CIELAB values of the samples were measured using a spectrophotometer. Then, for each sample, the die was obtained from polymethyl methacrylate. The specimens were cemented into dies and tested in a universal testing machine for fracture load. One-way ANOVA were performed to assess the effect of the sintering procedure on the marginal and internal fit, fracture load, and ∆E00, ∆L', ∆C', and ∆H' values of fixed partial prosthesis. PSL and PST groups showed significantly smaller internal and marginal fit compared to the IS group. Additionally, IST group internal fit values were significantly higher than Prettau groups. Sintering time reduction led to a decrease in ∆E00 values. Fracture loads values were not statistically significantly affected by the different sintering procedures in both brands. Different sintering procedures did not have a clinically significant effect on fit and fracture load. Different sintering procedures were found to have an impact on the color change of monolithic zirconia restorations.