[Remineralization of artificial root caries by fluoride dentifrice of different fluoride concentration in vitro]

Although the effectiveness of fluoride dentifrice in remineralizing enamel caries has been established, the optimum fluoride concentration for remineralization root caries has not been defined. The aim of this study was to assess and compare the effect of 1.1g/L, 1.45g/L and 5g/L fluoride dentifrices in remineralization of artificial root caries.

Sound human tooth fragments obtained from the cervical portion of root were stored in a demineralization solution for 96h at 37 degrees centigrade to induce artificial root caries lesions. The fragments were then randomly divided into four treatment groups including 1.1g/L, 1.45g/L, 5g/L fluoride dentifrice group and non-fluoride dentifrice control group. The demineralized samples were pH-cycled through treatment solutions, acidic buffer and neutral buffer for 8 days at 6 cycles per day. The samples were evaluated using electrical caries monitor(ECM), polarized light microscopy (PLM) and confocal laser scanning microscopy (CLSM). The data was analyzed using ANOVA with SPSS13.0 software package.

Variations of LgECM, total fluorescence and average fluorescence from CLSM after remineralization in fluoride dentifrice groups were significantly higher than those in the control group(P<0.05) Variations of LgECM, total fluorescence and average fluorescence from CLSM after remineralization in the 5g/L fluoride dentifrice group were significantly higher than those in the 1.1g/L and 1.45g/L fluoride dentifrice groups(P<0.05). PLM observation showed that a banding or deposit of mineral appeared within the lesions of specimens in the fluoride dentifrice groups. A wider mineral band was seen in the 5g/L fluoride dentifrice group than in the 1.1g/L and 1.45g/L fluoride dentifrice groups.

Fluoride dentifrice is effective in remineralizing artificial root caries and 5g/L fluoride dentifrice has better effect than 1.1g/L and 1.45g/L fluoride dentifrices.