THE FLOW-RATE AND ELECTROLYTE-COMPOSITION OF WHOLE SALIVA ELICITED BYTHE USE OF SUCROSE-CONTAINING AND SUGAR-FREE CHEWING-GUM

On two occasions, 12 adults collected unstimulated saliva and then eig ht samples of saliva over a 20-min period while chewing 3 g of either Wrigley's Spearmint sucrose-containing gum (SCG) or sugar-free gum (SF G) at 70 chews/min. The flow rates peaked initially, then fell with du ration of stimulation. With the SFG they were slightly but significant ly higher than with the SCG after 4 min of chewing. The sum of the con centrations of cations minus the sum of the concentrations of anions w as not significantly different from zero for saliva elicited by the SC G. However, for unstimulated saliva and that elicited by SFG, there wa s a slight positive anion balance. A second series of saliva collectio ns with SCG and SFG was made by the same 12 participants and these sam ples were analysed for lactate. For these collections the flow rates w ith SCG were not significantly less than with the SFG. The lactate con centration in saliva elicited by SCG peaked at 1.82 mmol/l in samples collected over 8-15 min, whereas samples of saliva elicited by SFG had a mean lactate concentration of 0.21 mmol/l. Of the lactate formed du ring the metabolism of sucrose by the oral bacteria, only 2% or less a ppeared to be derived from the metabolism of micro-organisms free in s aliva, the balance presumably being formed in dental plaque and enteri ng the saliva by diffusion. All saliva samples were supersaturated wit h respect to hydroxyapatite but stimulated saliva was significantly mo re supersaturated than unstimulated saliva. Saliva elicited by use of SFG will also tend to be more anticariogenic than that elicited by SCG because the former does not introduce a source of fermentable carbohy drate into the mouth.