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(TM) or Sprite Zero(TM) 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 Cu(2+), Mg(2+), Mn(2+) or Zn(2+) (1.25-60 mmol/L). For Coca-Cola(TM), the concentration of each ion that exhibited the highest protection was also evaluated in combination with Fe(2+). The phosphate or calcium released were analyzed spectrophotometrically. Data were analyzed using ANOVA and Tukey's test (p<0.05). RESULTS: For Coca-Cola(TM), the best protective effect was observed for Zn(2+) 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(TM), the best protective effect was observed for Cu(2+) at 15 and 30 mmol/L, which decreased the dissolution by 22-23%. Zn(2+) 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(TM). Regarding Sprite Zero(TM), the addition of Cu(2+) seems to be the best alternative.