Effect of gum chewing on the pH of dental plaque

J Clin Dent. 1992;3(3):75-8.


Saliva stimulation by gum chewing has been reported to neutralize plaque acidity. We compared the plaque pH response to bread with honey followed by sucrose-or sorbitol-sweetened gum chewing for 20 minutes. Bread and honey was chosen as previous work in our laboratory found this a worst case challenge in terms of the extent and duration of the pH decline. The study design was factorial with: 4 subjects x 2 replicates x 3 treatments. Each subject received each of the 3 treatments: food (bread and honey), food followed by sorbitol chewing gum, and food followed by sucrose chewing gum. Subjects accumulated plaque for 3 days on a partial prosthesis with a glass electrode set in the approximal space in the gap left by a missing first molar. Plaque pH was monitored for 150 min: baseline (0-10), food (11-30), +/- gum chewing (31-50), post-chew monitoring (51-150). ANOVA of mean plaque pH showed no difference between treatments at baseline. Significantly higher pH levels (p < 0.01) were shown with both gums compared to no gum during the chew and post-chew phases. Plaque pH data were also converted to absolute acid values (cH). Food alone produced 1703 mumol/min.; food followed by sorbitol chewing gum produced 53 mumol/min.; and food followed by sucrose gum produced 156 mumol/min. While the post-chew pH curves were not identical for sucrose vs. sorbitol chewing gums, both neutralized plaque acidity, probably due to the induced salivary action.

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • Chewing Gum*
  • Dental Plaque / chemistry*
  • Female
  • Humans
  • Hydrogen-Ion Concentration
  • Middle Aged
  • Salivation / physiology
  • Sorbitol
  • Sucrose


  • Chewing Gum
  • Sorbitol
  • Sucrose