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Background: The eventual sequel of dental caries is determined by the dynamic equilibrium between pathological factors which lead to demineralization and protective elements, which in turn leads to remineralization. Remineralization is the natural process for noncavitated demineralized lesions and relies on calcium and phosphate ions assisted by fluoride to rebuild a new surface on existing crystal remnants in subsurface lesions remaining after demineralization. Hence, the present study was designed to evaluate the efficacy of fluoride dentifrices in remineralizing artificial caries-like lesions in situ. Materials and Methods: A double-blind, randomized study with an initial washout period of 7 days was carried out for 3 weeks. Twenty volunteers were enrolled, who wore the intraoral cariogenicity test appliance having enamel slabs incorporated into them, for 3 weeks. 10 participants were instructed to use Group A dentifrice (fluoride) and the other 10 Group B dentifrice (nonfluoride) for brushing their teeth. The enamel slabs were analyzed by surface microhardness testing and scanning electron microscopy (SEM) at 3 intervals. Results: No significant differences was seen in the microhardness values recorded for Group A and Group B at baseline and after demineralization (P > 0.05); however Group B exhibited lesser microhardness compared to Group A, after intra-oral exposure (P < 0.05). In the SEM analysis, the Group A enamel surfaces had more regular and longer crystallites to those of the Group B. Conclusion: Fluoride dentifrices avert the decrease in enamel hardness and loss of minerals from the enamel surface to a large extent as compared to the nonfluoride dentifrices.

Background: Human endeavors to prevent dental caries have led to the use of different modalities and agents, the most commonly used of which is fluoridated dentifrice. An in situ study was carried out to evaluate the efficacy of fluoridated dentifrices in achieving remineralization of initial caries-like lesions using surface microhardness measurements and to study the qualitative changes by scan-ning electron microscopy. Methods: Sixteen children 12-16 years of age wore a specially fabricated appliance with an artificially demineralized enamel slab for 24 hours a day, for four weeks. The children were divided into two groups, A and B. Following one week use of placebo dentifrice by both groups, group A used a fluoride dentifrice containing l000 ppm sodium monofluorophosphate, whereas group B used a placebo twice daily for 5 minutes for 21 days. Surface microhardness test carried out using a Knoop diamond indenter followed by scanning electron microscopy to evaluate the lesions. The results were statistically analyzed using the student t test. P value less than 0.05 was considered significant. Results: The average hardness recovery for the experimental group was significantly higher than that in the control group (P < 0.001). Scanning electron microscopy revealed that fluoride significantly enhances remineralization of initial caries-like lesions. Conclusion : Regular use of fluoridated dentifrices significantly enhances remineralization of white spot lesions.