Effect of 4.5--year use of xylitol and sorbitol on plaque.

The pH values of xylitol-containing plaque suspensions of persons who habitually used xylitol and sorbitol during 3.2 to 4.5 years did not significantly differ from those observed with suspensions containing no added carbohydrates. Sorbitol produced in 22-hour incubations pH values as low as 3.9 to 5.5. The activity of plaque xylitol dehydrogenase was almost nil, whereas sorbitol dehydrogenase activity was higher. The nonacidogenic nature of xylitol in relation to plaque did not change in prolonged use of xylitol.