Changes in Salivary pH Due to Gum Chewing

Eating sweets and chewing gum are often said to lead to tooth decay. This study investigated whether gum is a cause of caries by measuring the pH of the reflex （stimulated）saliva secreted in large amounts as a result of chewing various commercially available brands of gum that are marketed as being good for teeth. Four brands of gum were used: Green Gum, which contains sugar, and Xylitol, Poscam, and Recaldent, which are sugar-fee. The control was a gum base. Experimental subjects were seven adult men and women. The pH of saliva rose at the start of gum chewing, but had largely returned to pre-chewing levels within 5min. Subsequently, with sugar-containing gum, pH decreased gradually until 40min, after which it showed a recovery trend. With the other types of gum,there was almost no change in pH after 5min.