Susceptibility of repigmentation of enamel surface to red wine and brandy staining after 35% hydrogen peroxide bleaching

Abstract
Aim and objectives: To investigate the susceptibility of enamel surface for repigmentation by red wine and brandy stains after 35% hydrogen peroxide bleaching. Methodology: 40 freshly extracted human permanent maxillary central incisor teeth were collected for the study. Incisors were stored in 0.1% thymol solution and were used within 1 month of extraction. The teeth were cleaned with ultrasonic scaler, polished with pumice paste. The samples were than divided into two groups of 20 incisors teeth each. Both groups of 20 teeth each were than bleached using 35% hydrogen Peroxide as per the manufacturer’s instructions, i.e. 15 minutes three times a day, every alternate day for four days. Group 1 were than immersed in 200 ml of red wine and group 2 were immersed in 200 ml of brandy for 15 minutes, 6 hours, 1 week and 1 month each. Advance spectrophotometer was used to measure the color shade of the teeth pre bleaching, after 15 minutes, after 6 hours, after 1 week and after 1 month of red wine and brandy immersion. The colour differences (ΔE) at each time interval were calculated accordingly. Results: Spectrometer analysis showed mean ΔE values ± standard deviation of group 1 and group 2 at different time intervals. Color change due to repigmentation was lowest for group 1 teeth from baseline to 15 minutes time interval. Mean ΔE value ± standard deviation was 4.04045±1.308029. However color change value was highest in group 2 teeth at 1 week to 1 month time interval and was 13.45717±1.098210. Group 2 teeth had higher ΔE value than group 1 at any point of time interval. Conclusions: It was concluded that low pH values causes more repigmentation of bleached enamel surface as it was found more with brandy in comparison to red wine. The bleaching treatment with 35% hydrogen peroxide enabled the teeth to become clearer; nevertheless, the intake of food and beverages containing colorants or an acidic pH can negatively affect the effectiveness of bleaching.