Erosive characteristics and fluoride content of cola-type drinks

Aim: Excessive consumption of carbonated soft drinks is detrimental to general and oral health. This study determined endogenous pH, titratable acidity (TA) and fluoride (F) ion concentration of cola-type drinks available in the UK. Subsidiary aims were to compare; i) endogenous pH and TA of drinks upon opening (T0) and after 20 minutes (T20); ii) endogenous pH, TA and F ion concentration of diet v regular and plastic v canned drinks. Methods: Endogenous pH, TA (mls 0.1M NaOH) and F ion (mg/L) of 71 products measured using pH meter and F-ISE. A Wilcoxon Signed Ranks Test compared pH and TAs at T0 and T20; a Mann-Whitney U test compared pH, TAs and F ion concentration for; a) regular v diet drinks; b) plastic v canned drinks. Results: Mean (±SD) pH for regular and diet drinks was 2.44± 0.12 and 2.83± 0.33 respectively (p=0.001); mean NaOH (ml) to raise pH to 5.5 and 5.7 was 5.49± 0.76 and 6.40± 0.78 (regular drinks); 5.17±1.03 and 6.03±1.07 (diet drinks). Diet (p=0.040) and regular (p=0.041) drinks had higher TA to pH 5.7 at T0 compared with T20; at T20 regular drinks had higher TA to pH 5.5 (p=0.026) and pH 5.7 (p=0.030) than diet drinks. There was no difference in F ion concentration between regular v diet drinks (p=0.754) and no significant container effect. Conclusion: Erosive characteristics were similar between manufacturers but higher erosive potentials were evident at T0 compared with 20 minutes later and for regular compared with diet drinks. F ion concentration of drinks was low.