Evaluation of the pH of a new carbonated soft drink beverage: an in vivo investigation.
PURPOSE: Recently, a modified version of a successful soft drink has been developed that aims to reduce the potential for dental erosion in consumers. The aim of this investigation was to compare the effect of the modified and original formula soft drink on the pH at various tooth surfaces during and after ingestion in subjects without erosion. MATERIALS AND METHODS: Fifteen subjects (10 female and 5 male) without dental erosion drank both a modified and an unmodified beverage for over 5 minutes in a randomized order. Oral pH was measured with antimony electrodes positioned on the labial and palatal surfaces of an incisor and premolar and held in place by a close-fitting vacuum-formed appliance. The results were compared (using the Wilcoxon signed rank test, with matched pairs) for the percentage and total time that pH fell below 4, 5, and 5.5. RESULTS: The percentage and total time that pH fell below 4 was significantly different between the drinks (P <0.02), but the total time that pH fell below 5 and 5.5 was not. The time taken for subjects to return to pre-exposure pH levels in the mouth showed considerable variation between individuals. CONCLUSIONS: The modified-formula drink appeared to have less erosive potential than the original formula when assessed by measuring pH at the tooth surface. Although the erosive potential has been reduced by modifying the soft drink, it has not been eliminated.