AbstractStatement of problem.
The effects of the application of aqueous coloring liquids on the mechanical properties of zirconia have not yet been investigated.Purpose.
The purpose of this in vitro study was to evaluate the effects of 3 different coloring techniques and the number of coloring liquid applications on the hardness of zirconia.Material and methods.
Eighty specimens were divided into 8 groups (n=10); nonshaded zirconia, preshaded zirconia, acid-based coloring liquid zirconia, and aqueous coloring liquid zirconia (1, 3, 6). Vickers hardness was measured. Data were analyzed via 1-way and 2-way ANOVAs. Multiple comparisons were performed using a Scheffé test (α=.05).Results.
Statistically significant differences in hardness were found between acid-based coloring liquid zirconia and aqueous coloring liquid zirconia (P<.001). Increasing the number of coloring liquid applications decreased the hardness value of acid-based coloring liquid zirconia (P<.001) but had no effect on the hardness of aqueous coloring liquid zirconia (P>.05).Conclusions.
Within the limitations of this study, the hardness of zirconia was influenced to differing degrees depending on coloring technique. The number of coloring liquid applications affected the hardness of zirconia colored with the acid-based coloring liquid but not the hardness of zirconia colored with the aqueous coloring liquid.