The effect of chewing bicarbonate-containing gum on salivary flow rate and pH in humans

Objective: Gum chewing increases salivary flow rate and pH. The aim of this study was to compare the effects of chewing standard sugar-free gum with those of a gum containing sodium bicarbonate. Design: Whole mouth saliva was collected from 20 volunteers who met inclusion criteria and gave informed consent. After unstimulated saliva was collected, stimulated saliva was collected at intervals during 30 min of chewing either a standard, mint-flavoured gum or bicarbonate-containing, mint-flavoured gum. The salivary flow and pH were measured for each sample. Results: With the standard gum, the mean peak salivary flow rate was 3.1±1.27 ml/min and the peak salivary pH was 7.39±0.14. With the bicarbonate gum, the peak flow rate was 2.79±1.38 ml/min and the peak salivary pH was 8.06±0.18. The salivary flow rates with the two gums were not significantly different; however, the increase in salivary pH was significantly greater for the bicarbonate gum. Conclusion: The increased salivary pH with bicarbonate gum may have implications for oral health and prevention of dental caries.