ALTERAÇÃO DA MICRODUREZA SUPERFICIAL DO ESMALTE DENTÁRIO EXPOSTOS A CHÁS INDUSTRIALIZADOS

The erosion capacity of industrialized teas on the dental enamel is evaluated according to the percentage of dental surface hardness loss (%DHL), pH, acid titration and buffer capacity. Six types of industrialized teas, featuring different brands and tastes, were analyzed. Mineral water-Crystal® and Coca-Cola® were respectively the negative and positive controls. Measurements of pH and titration were prepared in triplicate, in a 50ml beverage. Buffer capacity was calculated on pH rates and acid titration for pH 7.0. Micro-hardness of enamel surface was evaluated prior to and after the erosive test. ANOVA and Pearson´s correlation tests at p<0.05 were employed to analyze data which, in turn, provided normal distribution. There was significant difference between the teas and controls in all variables (ANOVA, p<0.05). The pH of teas ranged between 2.25 (Black tea with lemon) and 3.39 (Matte with lemon). Highest rates for acid titration (2.05) and buffer capacity (8.30) occurred in Black tea with lemon. Highest %DHL rate occurred in Peach tea, whilst the lowest in Natural Matte tea. There was a statistically significant difference in %DHL for all teas when compared to negative control and %PMD of all types of tea was higher than that of positive control. There were significant co-relationships (p<0.05) between initial pH initial with acid titration and buffer capacity, and between %PMD and initial pH, acid titration and buffer capacity. Results showed that all teas had an erosive trait on the dental enamel, with intensity variation according to taste and composition.