Supplementation of soft drinks with metallic ions reduces dissolution of bovine enamel

Objective: The aim of this study was to evaluate the effect of the addition of metallic ions to carbonated drinks on their erosive potential. Material and Methods: Powdered enamel was added to carbonated beverages (Coca-Cola™ or Sprite Zero™) and shaken for 30 s. The samples were then immediately centrifuged and the supernatant removed. This procedure was repeated 5 times with the beverages containing Cu2+, Mg2+, Mn2+ or Zn2+ (1.25-60 mmol/L). For Coca-Cola™, the concentration of each ion that exhibited the highest protection was also evaluated in combination with Fe2+. The phosphate or calcium released were analyzed spectrophotometrically. Data were analyzed using ANOVA and Tukey's test (p<0.05). Results: For Coca-Cola™, the best protective effect was observed for Zn2+ alone (10 mmol/L) or in combination (1 mmol/L) with other ions (12% and 27%, respectively, when compared with the control). Regarding Sprite Zero™, the best protective effect was observed for Cu2+ at 15 and 30 mmol/L, which decreased the dissolution by 22-23%. Zn2+ at 2.5 mmol/L also reduced the dissolution of powdered enamel by 8%. Conclusions: The results suggest that the combination of metallic ions can be an alternative to reduce the erosive potential of Coca-Cola™. Regarding Sprite Zero™, the addition of Cu2+ seems to be the best alternative.