Commercial soft drinks: pH and in vitro dissolution of enamel

Most soft drinks are acidic in nature and exposure to these drinks may result in enamel erosion. This study sought to measure the pH of 20 commercial brands of soft drinks, the dissolution of enamel resulting from immersion in these drinks, and the influence of pH on enamel loss. Comparison of the erosive potential of cola versus non-cola drinks as well as regular sugared and diet versions of the same brands was undertaken. The pH was measured immediately after opening the soft drink can. Enamel slices obtained from freshly extracted teeth were immersed in the soft drinks and weighed at baseline and after 6, 24, and 48 hours of immersion. Non-cola drinks had significantly higher pH values than cola drinks but showed higher mean percent weight loss. By contrast, sugared versions of the cola and non-cola drinks showed significantly lower pH values and higher mean percent weight loss than their diet counterparts. The pH value of the soft drink did not have a significant influence on the mean percent weight loss (r = -0.28). Prolonged exposure to soft drinks can lead to significant enamel loss. Non-cola drinks are more erosive than cola drinks. Sugared versions of cola and non-cola drinks proved to be more erosive than their diet counterparts. The erosive potential of the soft drinks was not related to their pH value.