Effects of frequent mouthrinses with palatinose and xylitol on dental plaque.

The aim was to evaluate the effects of frequent mouthrinses with palatinose, xylitol and a mixture of palatinose and xylitol on plaque pH, plaque formation and cariogenic microorganisms. 15 subjects refrained from toothbrushing during 3 test periods and rinsed 15 x daily for 4 d with 10 ml of: (1) 50% palatinose, (2) 37.5% palatinose + 12.5% xylitol, or (3) 50% xylitol. A contrast period with no mouthrinses was also carried out. The 4 periods were carried out in a randomized order with a cross-over design. After the 4-day periods, 3 parameters were measured: (1) plaque pH during the first 30 min after a mouthrinse with palatinose, a mixture of palatinose and xylitol or xylitol alone, directly followed by a 2nd rinse with 10% sucrose; (2) number of mutans streptococci and lactobacilli in plaque and saliva; (3) plaque index. The most pronounced pH drop for the sugar substitutes was found when rinsing with 50% palatinose after the palatinose period, and the least pH drop with 50% xylitol after the xylitol period. The sucrose rinse gave similar pH fall after all 4 periods. The microbial data showed no differences between the 4 periods, but the mutans streptococcus counts in saliva decreased after the xylitol period in contrast to the 3 other periods. Regarding the plaque index, xylitol gave lower scores compared to the other 3 periods.