Objectives. To evaluate the effect of polishing, glazing (add-on) and auto glazing on the color and translucency of three types of monolithic zirconia ceramics with different translucencies.
Material and methods. 84 sintered zirconia discs were divided into 3 groups (n=28) according to the type of zirconia: 3Y-TZP (HT), 3Y-TZP multilayered (HTML), and 5Y-PSZ multilayered (UTML). Each group was subdivided into 4 subgroups according to the surface treatment protocol: milled (M), polished (P), glazed (add-on) (G), and auto glazed (AG). Color difference (∆E) and translucency parameter (TP) were assessed by spectrophotometer. Statistical analysis revealed normal data distribution. One way analysis of variance (ANOVA) test was performed followed by Tukey`s Post Hoc test.
Results. Polishing in all groups had ∆E values of 1 or less, while glazing and auto glazing groups had ∆E values below 3.3, in groups HT and UTML. While in group HTML were above 3.3. Within each surface treatment, group UTML recorded the lowest ∆E, followed by group HT, and group HTML recorded the highest value.
Group UTML had significantly the highest translucency among surface treatment methods. Subgroup P values were significantly the highest and subgroup G values were significantly the lowest, in groups HT and UTML. In group HTML, polishing had higher translucency than glazing but without significant difference.
Conclusions. Polishing caused the least color change in all groups and enhanced the translucency of groups HT and UTML. An inacceptable color change could be detectable after glazing (add-on) and auto glazing of monolithic HTML zirconia.