Correlation between alteration of enamel roughness and tooth color.

Background: To establish the correlation between enamel roughness and color change of tooth.

Material and Methods: Enamel/dentin blocks (5 x 5 x 3.2 mm) were serially ground with the following abrasive paper: 1200-grit, 800-grit, and 600-grit SiC papers. In the paired model, the analyses of color (L*, a*, b*, ΔE) and roughness (Ra) were performed among the sandpaper exposure. The data were subjected to ANOVA using models for repeated measures followed by the Tukey test. The Pearson correlation test was used to determine whether there was a relationship between Ra values and color results (α = 0.05).

Results: The L* values decreased in accordance with the increase of Ra, with statistical difference between all the times ( p <0.05). A correlation was found between the Ra vs. the L* values (r = -0.67; p <0.0001) and ∆Ra vs. ∆a* values (r = 0.29; p = 0.05); besides that, there was no significant correlation with b* values or significant alteration in the ∆E values ( p >0.05).

Conclusions: The alteration of enamel roughness acted on the lightness and the green-red axis of tooth color. However, there was no significant correlation between the alteration of roughness of enamel and general color change of tooth. Key words: Surface properties, tooth discoloration, color.