Effect of Selected Fluoride Products on White Spot Lesions Remineralization

Remineralization therapies based on calcium and phosphate augmentation have been proposed as useful in reversing the decay process in early caries.  Objectives: This study compared the effect of selected fluoride formulations on remineralization of caries-like lesions. Methods: Human enamel specimens were demineralized for 96 hours according to the procedure of White (White, Caries Res 1987) to produce  artificially demineralized early caries lesions.  Following demineralization specimens were assessed by surface hardness analysis, stratified and assigned to one of 4 treatments groups: AC- Apa Care, Cumdente, Germany (1% nano HA + 1450 ppm F),  TMP- Tooth Mouse Plus, GC, Japan (10% CPP-ACP + 900 ppm F),  BM- Blend-a Med toothpaste, Procter & Gamble, USA (1450 ppm F) and P- placebo. Samples were pH -cycled for 21 days in a regimen as described by Featherstone et al. (Featherstone et al. 1986 ) including 6 hours demineralization, 16 hours remineralization, and fluoride product application: AC and BM twice a day, and TMP once a day (as per instructions). After cycling samples were re-tested for surface microhardness SMH and then cross sectioned for longitudinal  microhardness (CSMH) (Featherstone and White Caries Res 1987). Results: Treatments produced significant rehardening of surface enamel and protection from lesion progression in subsurface. For surface measurements ΔSMH = P =3,3 VHN (±1,3nsd), BM= 119,7VHN(±13,2sd),  AC= 142,3VHN(±16,3sd),  TMP=215VHN(±11,3sd) and for the body of the lesion (75µm deep) the observed KHN increasing was: P=2,8 KHN(±1,1nsd),BM =105,7KHN(±13,2sd),AC= 124,4KHN(±14,8sd),  TMP=79,2KHN(±9,8sd). Conclusions: All treatments provided protection to lesion surfaces and improvement in remineralization in subsurfaces, though none of the tested products caused total baseline rehardening or complete repair of examined samples. The CPP-ACP- F formulation revealed higher remineralizing effect of surface areas while  nano-HA-F based product demonstrate better ability to increasing  mineral content in the lesion of the body.