Intra-oral comparison and evaluation of the ability of fluoride dentifrices to promote the remineralization of Caries-like lesions in dentin and enamel

The effect of three types of fluoride dentifrices and one non-fluoride dentifrice were evaluated and compared intra-orally for their ability to promote the remineralization of caries-like lesions in thin sections of human dentin and enamel. The three fluoride dentifrices were silica based. One dentifrice contained 0.76% sodium monofluorophosphate (MFP), another contained 0.247% sodium fluoride (NaF), and the third contained 0.247% NaF plus 1.3% pyrophosphate and 1.5% polyvinylmethyl ether/maleic acid (PVM/MA) copolymer (denoted NaF/PP(i)). The fourth dentifrice (placebo) was also silica based, but contained no fluoride, and served as a negative control. Two week treatment resulted in the following percent mineral changes for the enamel specimens: +21 ± 16 for MFP, +10 ± 30 for NaF, +16 ± 15 for NaF/PP(i), and -30 ± 30 for the placebo. The respective percent mineral change values for the dentin specimens were +28 ± 20 for MFP, +22 ± 19 for NaF, +28 ± 18 for NaF/PP(i), and -34 ± 61 for the placebo. A statistical analysis revealed that the three fluoride dentifrices were significantly better (p < 0.05) than the placebo at promoting remineralization for both types of specimens. No significant differences were found among the three fluoride dentifrices. The following can be concluded from this study: 1) silica based dentifrices containing MFP and NaF are effective at remineralizing caries-like lesions in both enamel and dentin; 2) there was no statistical difference between NaF and MFP in their ability to promote remineralization; and 3) pyrophosphate does not interfere with the remineralizing effects of NaF.