Introduction:

Many studies have been conducted about the effectiveness of tooth whitening, but few refer to color regression (a phenomenon occurring after tooth whitening) or to smoking patients.

Objective:

Determine color luminosity regression in smoking and nonsmoking patients undergoing home tooth whitening with 10 % carbamide peroxide.

Methods:

A descriptive cross-sectional study was conducted of 43 patients from a group of 60 previously undergoing home treatment with 10 % carbamide peroxide for 3 weeks. The patients were divided into an experimental group (EG, smoking patients) and a control group (CG, nonsmoking patients). A Vita Easyshade® spectrophotometer was used to measure color variation one week, one month, 6 months and 9 months after whitening. The data obtained by spectrophotometry were analyzed with the Shapiro-Wilk and the Kolmogorov-Smirnov tests to evaluate the normality of the distribution, and then they were subjected to the Mann-Whitney-Wilcoxon U test (α = 0,05).

Results:

Delta L* was 2,3 (EG) and 3,66 (CG); delta values were estimated from data obtained 9 months vs. one week after whitening. No statistically significant differences were found between the groups.

Conclusions:

No statistically significant color regression differences are found in either smoking or nonsmoking patients after home whitening with 10 % carbamide peroxide.

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