title: Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice.
abstract: Fingernail has been suggested as a biomarker of fluoride (F) body burden, but there is no consensus if it would be a reliable indicator of F exposure from dentifrice. Therefore, the present study was conducted to investigate if fingernails would have sensitivity to detect F exposure from dentifrice in young children. Twenty-three 1-3-year-old children living in the city of Piracicaba (0.72 ppm F in water), Brazil, were enrolled in two phases of different F exposure: in phase A (1st to 11th week), they were exposed to the combination of F from diet (solids and liquids) and dentifrice (1,500 microg F/g as MFP), and in phase B (12th to 29th week), only to F from diet (the use of F dentifrice was interrupted). Fingernails were weekly clipped during 35 weeks for F determination. F intake from diet and dentifrice in each phase was also determined. Both analyses were made with ion-specific electrode. F intake (Mean +/- SD) was significantly higher (p<0.01) when the children were exposed to F from diet+dentifrice than only to F from diet (0.086 +/- 0.032 and 0.040 +/- 0.009 mg F/day/kg body weight, respectively). However, F concentrations in nails collected during the whole experimental period of 35 weeks presented great variation with no trend of decreasing after F dentifrice intake interruption. The findings suggest that fingernail may not be a reliable F biomarker of body burden from dentifrice.
authors.affiliation: São Leopoldo Mandic School of Dentistry and Research Center, Campinas, SP, Brazil.
authors.forename: Ynara Bosco Oliveira
authors.initials: YB
authors.lastname: Lima-Arsati
authors.forename: Carolina Castro
authors.initials: CC
authors.lastname: Martins
authors.forename: Lília Alves
authors.initials: LA
authors.lastname: Rocha
authors.forename: Jaime Aparecido
authors.initials: JA
authors.lastname: Cury
mesh_terms: D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001822:Body Burden; D002327:Cariostatic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis* / Q000378:metabolism; D005260:Female; D005457:Fluoridation; D005459:Fluorides / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis* / Q000378:metabolism; D005460:Fluorides, Topical / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis* / Q000378:metabolism; D009050:Fluorosis, Dental / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D009262:Nails / Q000737:chemistry* / Q000378:metabolism; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014100:Toothpastes / Q000008:administration & dosage / Q000032:analysis
chemical_list: D015415:Biomarkers; D002327:Cariostatic Agents; D005460:Fluorides, Topical; D014100:Toothpastes; D005459:Fluorides