Statement of problem:Veneered polyetheretherketone(PEEK) is a recent alternative choice for fixed dental prostheses.There is a lack of data about the color stability of different veneering composite techniques of CAD/CAM PEEK cores.
Purpose:To verify the effect of thermocycling and different mouth rinses on color stability of CAD/CAM composite versus conventional nanohybrid composite veneered PEEK crowns.
Methods:Forty-two duplicated epoxy resin dies of prepared mandibular first molar to receive ceramic crown were fabricated.42 CAD/CAM PEEK cores were fabricated and divided into two groups(n=21)based on the veneering technique;group(C):nanohybrid crea.lign composite veneered PEEK cores and group(H):HIPC veneered PEEK cores. Each group was subdivided based on mouth rinse into 3 groups(n=7):Listerine-alcohol free, Hexitol and Distilled water.The color at baseline, after thermocycling equivalent to clinical 6 months service and 1-week immersion in mouth rinses were measured utilizing a spectrophotometer.The data were statistically analyzed using ANOVA,pair-wise Tukey's post-hoc and student t-tests to reveal the significance between groups(P ≤ 0.05).
Results:All specimens showed visually unperceptible color differences after thermocycling and immersing in mouth rinses(∆E*<3.3).Based on material,C group showed a statistically significant higher color change values than H group.ANOVA test revealed that the highest color change was for Hexitol followed by Listerine then distilled water(p=<0.0001<0.05).Tukey's post-hoc test showed non-significant difference between Hexitol and Listerine.The interaction between the effect of mouth rinses and type of veneering composite materials was statistically non-significant for C group while significant for H group(P>0.05).
Conclusions:Although visually nonperceptible,HIPC or nanohybrid composite veneered PEEK crowns showed a color difference after thermocycling and immersion in different mouth rinses.