Effect of beverages on bovine dental enamel subjected to erosive challenge with hydrochloric acid

Abstract

This study evaluated by an in vitro model the effect of beverages on dental enamel previously subjected to erosive challenge with hydrochloric acid. The factor under study was the type of beverage, in five levels: Sprite ® Zero Low-calorie Soda Lime (positive control), Parmalat ® ultra high temperature (UHT) milk, Ades ® Original soymilk, Leão ® Ice Tea Zero ready-to-drink low-calorie peach-flavored black tea and Prata ® natural mineral water (negative control). Seventy-five bovine enamel specimens were distributed among the five types of beverages (n=15), according to a randomized complete block design. For the formation of erosive wear lesions, the specimens were immersed in 10 mL aqueous solution of hydrochloric acid 0.01 M for 2 min. Subsequently, the specimens were immersed in 20 mL of the beverages for 1 min, twice daily for 2 days at room temperature. In between, the specimens were kept in 20 mL of artificial saliva at 37ºC. The response variable was the quantitative enamel microhardness. ANOVA and Tukey's test showed highly significant differences (p<0.00001) in the enamel exposed to hydrochloric acid and beverages. The soft drink caused a significantly higher decrease in microhardness compared with the other beverages. The black tea caused a significantly higher reduction in microhardness than the mineral water, UHT milk and soymilk, but lower than the soft drink. Among the analyzed beverages, the soft drink and the black tea caused the most deleterious effects on dental enamel microhardness.

Erosive Potential of Industrialized Teas: An in vitro study

“…This finding is consistent with some authors [3], who performed an erosive challenge using Black Tea (Leão ® ) and observed a significant change in the surface hardness of the dental enamel exposed to this tea, before and after the erosive test, despite presenting fluoride in its composition. It was observed that the amount of fluoride present was unable to promote enamel protection when there is a previous erosive challenge with HCl or in the presence of acids from carbonated beverages [3].…”

“…Mineral water (Indaiá ® ) also had pH lower than value considered critical for dental tissues; however, its high buffering capacity facilitates its neutralization by the saliva, when present in the oral environment, thus being considered the beverage with less erosive potential. Due to these characteristics, mineral water (Indaiá ® ) was used as a negative control in this research, since it does not present any erosive substance in its composition [3].…”

“…This can be explained by its composition [19], since this tea has citric and phosphoric acids in its composition [3], and also due to the addition of concentrated lemon juice, fruit with high citric acid content [19]. Acid is added to accentuate the taste of lemon, but has high capacity for chelating minerals and is responsible for tooth erosion [20].…”

“…It was observed that the amount of fluoride present was unable to promote enamel protection when there is a previous erosive challenge with HCl or in the presence of acids from carbonated beverages [3].…”

“…Extrinsic causes involve acidic drugs such as vitamin C, in addition to the consumption of acidic foods and beverages [2]. Dental erosion is a multifactorial condition 2 whose chemical, biological and behavioral interactions help explain why some individuals have more manifestations of this pathology than others [3]. However, the most relevant acids that can cause dental erosion are from the diet [4] and from the stomach [5].…”