Fluoride dose-response of human and bovine enamel caries lesions under remineralizing conditions.
OBJECTIVE
To investigate the relative fluoride dose-response of human and bovine enamel caries lesions under remineralizing conditions and utilizing an established pH cycling model.


METHODS
Early caries-like lesions were formed in human and bovine enamel, characterized using Vickers surface microhardness (VHN) and assigned to five dentifrice treatment groups: 0/250/1100 ppm fluoride as sodium fluoride (F as NaF) formulation 1; 1100 ppm F as NaF formulation 2; 1000 ppm F as monofluorophosphate (MFP) formulation 3. The daily pH cycling regimen comprised: 4x1-minute dentifrice slurry treatments; 1 x 4-hour acid challenge and intermittent remineralization in a 1:1-mixture of pooled human/artificial saliva. After 20 days, VHN of specimens were measured again and changes from lesion baseline calculated (REM). Subsequently, enamel fluoride uptake (EFU) was determined using the microdrill technique and specimens were demineralized again to determine their acid resistance (DEM). Data were analyzed using two-way ANOVA (factors: enamel, dentifrice).


RESULTS
Both enamel type and dentifrice as well as their interaction affected REM and DEM. EFU was only affected by dentifrice. Human and bovine enamel showed a good fluoride dose-response for REM and correlated well. However, bovine enamel showed more remineralization than human enamel. There were good correlations between dentifrice-F concentration vs. REM and EFU, and between REM vs. EFU, regardless of enamel type.
Department of Preventive and Community Dentistry, Oral Health Research Institute, Indiana University School of Dentistry, 415 Lansing Street, Indianapolis, IN 46202, USA. flippert@iupui.edu
Frank
F
Lippert
Anderson Takeo
AT
Hara
D000818:Animals; D002327:Cariostatic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002417:Cattle; D003731:Dental Caries / Q000188:drug therapy*; D003743:Dental Enamel / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005459:Fluorides / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006244:Hardness; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000008:administration & dosage / Q000493:pharmacokinetics; D012463:Saliva; D012464:Saliva, Artificial; D012969:Sodium Fluoride / Q000008:administration & dosage / Q000493:pharmacokinetics; D013045:Species Specificity; D014089:Tooth Remineralization / Q000379:methods*
D002327:Cariostatic Agents; D010710:Phosphates; D012464:Saliva, Artificial; C012980:fluorophosphate; D012969:Sodium Fluoride; D005459:Fluorides