Effect of xylitol:sorbitol on fluoride enamel demineralization reduction in situ.

OBJECTIVES: To evaluate if sugar alcohols would reduce enamel demineralization enhancing the fluoride (F) effect. METHODS: A crossover in situ study was conducted in four phases, during which 10 volunteers were submitted to one of the treatments: (I) Distilled and deionized water, as a negative control; (II) F (226 microg F/ml as NaF; concentration used in commercial mouthrinse); (III) X:S (xylitol:sorbitol 1:3; final concentration 1.6M; 28% of sugar alcohols) and (IV) F+X:S (same final concentration that groups II and III). The volunteers wore palatal appliances containing four bovine enamel blocks of known surface microhardness (SMH), covered with a 'test plaque' of mutans streptococci, which were immersed during 1 min in one of the allocated treatment solutions simultaneously that the volunteers rinsed their mouths with the same solution. After the rinsing the appliances were put in the mouth and after 20 min a cariogenic challenge was made with 20% sucrose solution during 1 min. After further 45 min the 'test plaque' was collected for F analysis, enamel SMH was again determined and the percentage of change in relation to baseline was calculated; F uptake in enamel was also determined. RESULTS: With respect to all the analyses made, the group F+X:S did not differ from the F treatment (p>0.05) and the groups treated with F and F+X:S differed from the negative control (p<0.05). CONCLUSIONS: The results suggest that xylitol:sorbitol may not enhance the effect of fluoride present in mouth rinse on the reduction of enamel demineralization.

Effect of a calcium carbonate-based dentifrice on in situ enamel remineralization.

This crossover study evaluated the effect of calcium carbonate (CaCO(3))-based monofluorophosphate dentifrice on enamel remineralization. Ten volunteers wore palatal appliances containing four enamel blocks with caries-like lesions, two of them covered by a test plaque of mutans streptococci. The following treatments were evaluated: a negative control, a silica-based or a CaCO(3)-based dentifrice, and the percentage of enamel surface microhardness recovery was determined. The CaCO(3)-based dentifrice was more effective than the negative control on the enhancement of enamel remineralization, either in the presence or absence of test plaque. This efficacy was also shown by the silica-based dentifrice but only in the presence of test plaque.

Effect of a calcium carbonate-based dentifrice on enamel demineralization in situ.

Since the effect of calcium carbonate (CaCO(3)) based dentifrice on enamel demineralization is not clearly established, it was evaluated using the IEDT model described by Zero's group in 1992. This study had a crossover design and 10 volunteers were submitted to 3 treatment groups: a negative control, brushing without dentifrice; an active control, brushing with silica-based dentifrice (SiO(2)/MFP group), and the experimental group, brushing with CaCO(3)-based dentifrice (CaCO(3)/MFP). Both dentifrices contained 1,500 microgram F/g (w/w) as sodium monofluorophosphate (MFP). Enamel surface microhardness was determined in the dental blocks and the percentage change in relation to baseline was calculated. Fluoride uptake in enamel and its concentration in 'test plaque' were determined. The results showed that the dentifrice containing CaCO(3)/MFP was more effective than SiO(2)/MFP in reducing enamel demineralization (p < 0.05). A higher concentration of fluoride ion was found in 'test plaque' treated with CaCO(3)/MFP than in the negative control (p < 0.05). The results suggest that CaCO(3) abrasive may enhance the effect of fluoride present in dentifrice on dental caries control.