Influência do tabagismo na alteração de cor e genotoxicidade das células orais após clareamento dental caseiro com peróxido de carbamida 22%: estudo de coorte

Abstract

OBJECTIVES: To evaluate the effect of smoking on the color change and genotoxicity after at-home bleaching. METHODOLOGY: this is a cohort study with 40 patients between 18 and 54 years old, divided into 2 groups (n = 40): NFnonsmokers (n = 24) and F- smokers (n = 16). The groups were submitted to athome bleaching with 22% carbamide peroxide (PC), with individual trays for 1 hour a day, for 14 days. Color analyzes and cellular alteratios were performed before bleaching (T0-baseline), one day (T15), 15 days (T30) and 1 month (T45) after treatment finishing. The color was measured using the Vita Easyshade ™ spectrophotometer. The whitening index (WID-Whiteness Index for Dentistry) was calculated to evaluate the efficacy of bleaching. The color differences between F and NF at different times were calculated using the CIELAB (ΔE*ab) and CIEDE2000 (ΔE00) equations. Genotoxicity was assessed by counting micronuclei (MN) and metanuclear alterations (AM) in cells of the superficial scraping of the upper and lower marginal gingiva (1,000 cells per patient). The material was stained by Giemsa at 10% and analyzed under a photonic microscope by a trained observer. Data collection and analysis occurred blindly. Descriptive analysis was performed. Socio-demographic variables were compared by chi-square and Pearson´s correlation. Color change comparisons between F and NF by dental group (IC - central incisors. IL - lateral incisors and C-canine) and the frequency of MN and AM were performed by Mann-Whitney (α = 0.05). RESULTS: Baseline (T0) whiteness index (WID) was similar between F and NF. NF showed higher WID than F at all other evaluation times. NF showed difference in whiteness index (ΔWID) of CI and C (lighter) between (T0) and the other times (T15), (T30) and (T45) compared to F. In general, the color differences detected by ΔE*ab and ΔE00 followed WID. The F showed a higher darkening of IC than NF in ΔWID (T45-T15). Regarding the amount of MN and AM, no significant differences were found between groups at the evaluated times (p>0.05). CONCLUSIONS: At-home bleaching treatment with CP 22% can be negatively affected by smoking. The treatment is considered safe for genotoxicity using the bleach protocol of this study.