Effect of surface treatments on color of machinable ceramics

Abstract

Aim: The purpose of this study is to evaluate the effect of surface treatments on color of lithium disilicate ceramic (IPS e. max [CAD]) and hybrid ceramic (VITA Suprinity [pc]). Method: Ceramic blocks were sectioned in to one hundred sixty discs; eighty discs of lithium disilicate were randomly subdivided in to four groups according to surface treatment (n= 20). Group C: Control group without surface treatment; group I: using (AL2O3) particles size 50µm; group II: Hydro fluoric (HF) acid etching; group III: tribochemical (TBC) surface treatment. Eighty discs of hybrid ceramic (n= 20) were subdivided in to the same groups. Color measurements were performed with spectrophotometer and repeated after surface treatments. ∆E values were statistically analyzed with one- way ANOVA, Tukey's post hoc test was done to identify significance between groups. Statistically significance was considered when P value ≤ 0.05. Results: Changing color of lithium disilicate specimens were not clinically perceptible except for hydrofluoric acid etching as it was below the clinically accepted threshold (∆E 2.7 which were clinically unaccepted. Conclusion: Different techniques; sand blasting, HF acid etching and tribochemical surface treatments affected color significantly.