Dentifrice Effects With Xylitol and CPP-ACP: Enamel Caries In Vitro

Objectives: Effects of xylitol dentifrice with sodium monofluorophosphate (MFP) on in vitro enamel caries was compared with NaF (sodium fluoride) dentifrice and Casein Phosphopeptide-Amorphous Calcium Phosphate with NaF (CPP-ACP-Fl) dentifrice.
Methods: Enamel surfaces from caries-free permanent teeth (n=10) underwent debridement and fluoride-free prophylaxis. Teeth were sectioned into quarters, and acid-resistant varnish was placed with 2 sound enamel surface windows exposed on each tooth quarter. Each quarter from single tooth was assigned to treatment group: 1) No Treatment Control (synthetic saliva treatment only); 2) NaF dentifrice (Crest Cavity Protection Regular Paste, 0.243% NaF, Procter & Gamble); 3) Xylitol-MFP dentifrice (MyntSmile, 20% xylitol, 0.83% MFP, MyntSmile Oral Health Care Products); 4) CPP-ACP-FL dentifrice (MI Paste One, 0.243% NaF, 5% KNO3, 10% CPP-ACP). Tooth quarters were treated with dentifrice twice daily (180s) followed by synthetic saliva rinsing over 7d period. In vitro enamel caries were created using acidified gel (pH 4.25, 42 days). Longitudinal sections (3/tooth quarter, 60 lesions/group) were evaluated for mean lesion depths (water imbibition, polarized light, ANOVA, DMR).
Results: Mean lesion depths were 283±24 μm No Treatment Control; 207±19 μm NaF dentifrice; 223±31 μm Xylitol-MFP dentifrice; 181±16 μm CPP-ACP-FL dentifrice. All treatment agents had mean lesion depths significantly less than No Treatment Controls (P<.05). There was no significant difference in mean lesion depths between NaF and Xylitol-MFP dentifrices (P>.05). However, CPP-ACP-FL dentifrice provided a significant decrease in lesion depth compared with the other dentifrices (P<.05)
Conclusions: Commercially available fluoridated dentifrices provided significant reductions in in vitro enamel caries lesion depths compared with those exposed only to synthetic saliva rinsing (P<0.05). NaF dentifrice reduced lesion depth similar to the Xylitol-MFP dentifrice (P>0.05). CPP-ACP-Fl dentifrice had the greatest effect on caries reduction among treatment groups (P<.05). Of note, this in vitro physicochemical caries system does not assess potential beneficial effects of xylitol on biofilms and cariogenic bacteria acid production. Greatest caries reduction effect among treatment agents was with CPP-ACP-Fl dentifrice (P<.05).