Variation in pH of plaque after a mouth rinse with a saturated solution of mannitol

Plaque pH changes were studied in a group of 18 persons after a mouth rinse for 30 seconds with a 50 per cent (w/v) solution of sucrose. One week later the experiment was repeated on the same group of persons, but then with a saturated solution of mannitol instead of sucrose. Dental plaque material was collected from 15 different areas equally distributed among all the teeth. The changes in H-ion concentration in plaque were studied 2, 5, 10, 20, and 30 minutes after the rinse. Saturated mannitol caused an insignificant pH-increase at 2 minutes after which the pH-values remained unchanged. The sucrose (50 per cent) markedly lowered the pH-value, with the lowest value at 5 minutes, after which it slowly rose. The differences were highly significant at all intervals.