title: pH-cycling models to evaluate the effect of low fluoride dentifrice on enamel de- and remineralization.
abstract: Since the currently available pH-cycling models do not differentiate the anti-caries potential of dentifrices with low fluoride (F) concentration, two models were developed and tested in the present. Bovine enamel blocks were subjected to the models and treated with F solutions containing from 70 to 280 microg F/mL in order to validate them in terms of dose-response effect. The models were also tested by evaluating the dentifrices Colgate Baby (500 microg F/g, as a low fluoride dentifrice), Tandy (1,100 microg F/g, as an active F-dentifrice) and Crest (1,100 microg F/g, as positive control). Enamel mineral loss or gain was assessed by surface and cross-sectional microhardness, and lesion depth was analyzed by polarized light microscopy. The pH-cycling models showed F dose-response effect either reducing enamel demineralization or enhancing remineralization. The low F dentifrice presented anti-caries potential, but it was not equivalent to the dentifrices containing 1,100 microg F/g. These data suggest that the models developed in this study were able to evaluate the anti-caries potential of low F dentifrice either on resistance to demineralization or on enhancement of remineralization.
authors.affiliation: Department of Physiological Sciences, School of Dentistry of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Celso Silva
authors.initials: CS
authors.lastname: Queiroz
authors.forename: Anderson Takeo
authors.initials: AT
authors.lastname: Hara
authors.forename: Adriana Franco
authors.initials: AF
authors.lastname: Paes Leme
authors.forename: Jaime Aparecido
authors.initials: JA
authors.lastname: Cury
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis; D002327:Cariostatic Agents / Q000008:administration & dosage*; D002417:Cattle; D003743:Dental Enamel / Q000187:drug effects* / Q000648:ultrastructure; D003747:Dental Enamel Solubility / Q000187:drug effects; D003802:Dentifrices / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005459:Fluorides / Q000008:administration & dosage*; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008859:Microscopy, Polarization; D008903:Minerals / Q000032:analysis; D011897:Random Allocation; D012824:Silicic Acid; D012822:Silicon Dioxide / Q000008:administration & dosage; D012969:Sodium Fluoride / Q000008:administration & dosage; D013696:Temperature; D013997:Time Factors; D017001:Tooth Demineralization / Q000473:pathology / Q000517:prevention & control*; D014089:Tooth Remineralization; D014100:Toothpastes
chemical_list: D002327:Cariostatic Agents; D003802:Dentifrices; D008903:Minerals; D014100:Toothpastes; C546060:hydrated silica gel-based toothpaste; D012824:Silicic Acid; D012822:Silicon Dioxide; D012969:Sodium Fluoride; D005459:Fluorides; D002118:Calcium