Six Months of Daily High-Dose Xylitol in High-Risk Schoolchildren: A Randomized Clinical Trial on Plaque pH and Salivary Mutans Streptococci

A randomized clinical trial was designed to evaluate the effect of daily high-dose xylitol chewing gum on plaque pH and salivary mutans streptococci (MS) in a sample of schoolchildren at high risk of caries. The study was performed on 204 subjects (acceptance rate 88.3%). Inclusion criteria were: >1 and <4 carious lesions, and a salivary MS concentration >10(5) CFU/ml. Subjects were randomly assigned to the xylitol or control group. Study design included one examination at baseline (t(0)), one after 3 months of chewing (t(1)), one after 6 months of chewing (t(2)) and the last 3 months after the end of chewing period (t(3)). Plaque pH was assessed using the MicroTouch technique, following a sucrose challenge. The area under the curve (AUC(5.7) and AUC(6.2)) was recorded. Whole saliva was collected in sterile vials and MS CFU/ml were counted. Data were analysed using repeated-measures ANOVA. The main result was that plaque acidogenicity was reduced in both groups. The differences between treatments were statistically significant both for plaque pH and MS concentration; the interaction term for treatment and time was statistically significant (p < 0.01). At t(2), the xylitol group children with a salivary MS concentration >10(5) and those with <= 10(5) showed significantly lower AUC(5.7) and AUC(6.2) values than the control group. These results suggest that the long-term use of high-dose non-sucrose chewing gums had beneficial effects on plaque pH, and that this effect was statistically greater when using xylitol chewing gums, both on plaque pH and MS salivary concentration. Copyright (C) 2009 S. Karger AG, Basel