Effects of Different Whitening Toothpastes on the Color of Aged Zirconia-Reinforced Lithium Silicate Ceramics After Immersion in an Acidic Beverage.

INTRODUCTION

This study is aimed at comparing the effects of different whitening toothpastes on the color of aged ZLS ceramics after immersion in an acidic beverage.

MATERIALS AND

METHODS

In this in vitro study, 72 cylindrical (2×10 mm) ZLS ceramic specimens were sintered, polished, and randomly assigned to six groups (n = 12) of distilled water (D), distilled water + Colgate Total Whitening (DT), distilled water + Perfect White black (DP), cola (C), cola + Colgate Total Whitening (CT), and cola + Perfect White black (CP). After 5000 thermal cycles, the specimens were immersed in an acidic beverage for 6 days. The specimens in groups CP, CT, DP, and DT were brushed at 40 rpm for 2.33 min. The CIEL ∗a ∗b ∗ color parameters were measured spectrophotometrically before and after aging and toothbrushing. Data were analyzed by one-way ANOVA (alpha = 0.05).

RESULTS

The color change (ΔE) was not clinically detectable in any group (< 3.3). ΔE of the CT group was significantly greater than that of the C (mean difference: 0.12, p < 0.05) and the CP (mean difference: 0.13, p < 0.05) groups. ΔL of the C group was significantly greater than that of the CP group (mean difference: 0.21, p < 0.05). The differences in Δa and Δb were not significant among the groups (p > 0.05).

CONCLUSIONS

The application of Colgate Total Whitening and Perfect White black toothpaste for 6 weeks, along with simulated 6-month cola consumption, did not cause a clinically detectable change in the color of aged ZLS ceramics.