The influence of smoking on the effectiveness of at-home bleaching: A prospective clinical study

To evaluate the effect of smoking on tooth whitening and color change after at-home bleaching.

This prospective clinical study evaluated two groups of participants: NS-non-smokers (n = 24) and S-smokers (n = 16). All subjects were treated with at-home bleaching using 22% carbamide peroxide (CP) for 1 h/day for 14 days. Color coordinates (L*-luminosity, a*-red-green axis and b*-yellow-blue axis) were obtained before bleaching (D0-baseline), 1 day (D1), 15 days (D15), and 1 month (D30) after bleaching. The whiteness index (WI_D ) and CIEDE2000 color differences (ΔE₀₀ ) were calculated for S and NS. Color changes between S and NS subjects for specific teeth (CI-Central Incisors, LI-Lateral Incisors, and C-Canines) were analyzed using the Mann-Whitney test (α = 0.05).

There was no significant difference in WI_D between S and NS subjects at baseline. NS participants showed higher WI_D than S at D1, D15, and D30 (p < 0.05). NS showed higher ΔWI_D for CI and C between D0 and the other evaluation times (D1, D15, and D30) compared to S. Smokers showed higher darkening of CI than NS in ΔWI_D D30-D1 (p < 0.05). Color changes showed similar overall behavior for ΔWI_D . For all evaluation times, ΔWI_D and ΔE₀₀ values were below the corresponding acceptability thresholds.

At-home bleaching was effective on smokers and nonsmokers. Smoking negatively affected color stability after bleaching. ΔE₀₀ and ΔWI_D were acceptable for both groups.

Although smoking negatively affected color stability after bleaching, the observed changes were clinically acceptable.