title: Enamel demineralization and remineralization under plaque fluid-like conditions: a quantitative light-induced fluorescence study.
abstract: The present study investigated de- and remineralization in enamel lesions under plaque fluid (PF)-like conditions using quantitative light-induced fluorescence (QLF). Preformed lesions were exposed to partially saturated lactic acid solutions, varying in pH and fluoride concentration ([F]) based on a 5 × 3 factorial study design (0/0.1/0.5/1.5/4 ppm F; pH 4.9/5.2/5.5). Average fluorescence loss (ΔF) was monitored for 11 days. Subsequently, lesions were demineralized in a partially saturated acetic acid solution for two 24-hour periods. Data were analyzed using repeated measures analysis of covariance. Lesions exposed to PF at 4 ppm F and pH 5.5 showed not only the most remineralization (ΔΔF = 28.2 ± 14.0%) for all groups after 11 days, but also the most demineralization (ΔΔF = -19.3 ± 13.5%) after subsequent acetic acid exposure. Increased [F] resulted in more remineralization, regardless of pH. Higher pH values resulted in more remineralization. No remineralization was observed in lesions exposed to F-free solutions, regardless of pH. Remineralization was noticeable under the following conditions: pH 4.9 - [F] = 4 ppm, pH 5.2 - [F] ≥ 1.5 ppm, and pH 5.5 - [F] ≥ 0.5 ppm. Overall, [F] had a stronger effect on remineralization than pH. Subsequent demineralization showed that little protection was offered by PF-like solutions, and further demineralization compared with baseline was observed on lesions not remineralized initially. [F] had a stronger effect on net mineral change than pH. The present study has shown that QLF is a valuable tool in studying lesion de- and remineralization under PF-like conditions, where [F] was shown to be more important than pH.
authors: Department of Preventive and Community Dentistry, Oral Health Research Institute, Indiana University School of Dentistry, Indianapolis, 46202, USA. flippert@iupui.edu
authors: F
authors: F
authors: Lippert
authors: A
authors: A
authors: Butler
authors: R J M
authors: RJ
authors: Lynch
mesh_terms: D019342:Acetic Acid / Q000009:adverse effects; D000818:Animals; D002327:Cariostatic Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002417:Cattle; D003732:Dental Caries Activity Tests; D003743:Dental Enamel / Q000378:metabolism; D003773:Dental Plaque / Q000737:chemistry*; D005122:Exudates and Transudates / Q000737:chemistry; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D008027:Light; D012969:Sodium Fluoride / Q000493:pharmacokinetics / Q000627:therapeutic use*; D017001:Tooth Demineralization / Q000139:chemically induced / Q000175:diagnosis* / Q000378:metabolism*; D014089:Tooth Remineralization / Q000379:methods
chemical_list: D002327:Cariostatic Agents; D012969:Sodium Fluoride; D019342:Acetic Acid