Validation of fingernail fluoride concentration as a predictor of risk for dental fluorosis

• Published in: Caries research Vol. 46; no. 4; p. 394
• Main Authors: Buzalaf, M A R, Massaro, C S, Rodrigues, M H C, Fukushima, R, Pessan, J P, Whitford, G M, Sampaio, F C
• Format: Journal Article
• Language: English
• Published: Switzerland 01-07-2012
• Subjects: Adolescent; Age Factors; Bicuspid - pathology; Biomarkers - analysis; Cariostatic Agents - analysis; Child; Child, Preschool; Dose-Response Relationship, Drug; Female; Fluoridation; Fluorides - analysis; Fluorosis, Dental - classification; Fluorosis, Dental - etiology; Follow-Up Studies; Forecasting; Humans; Incisor - pathology; Male; Nails - chemistry; Predictive Value of Tests; Risk Factors; Sensitivity and Specificity; Water Supply - analysis
• ISSN: 1421-976X
• DOI: 10.1159/000339088

The aim of this study was to validate the use of fingernail fluoride concentrations at ages 2-7 years as predictors of the risk for developing dental fluorosis in the permanent dentition. Fifty-six children of both genders (10-15 years of age) had their incisors and premolars examined for dental fluorosis using the Thylstrup-Fejerskov index. Fingernail fluoride concentrations were obtained from previous studies when children were 2-7 years of age. Data were analyzed by unpaired t test, ANOVA, and Fisher's exact test when the fingernail fluoride concentrations were dichotomized (≤ 2 or >2 µg/g). Children with dental fluorosis had significantly higher fingernail fluoride concentrations than those without the condition, and the concentrations tended to increase with the severity of fluorosis (r(2) = 0.47, p < 0.0001). Using a fingernail fluoride concentration of 2 µg/g at ages 2-7 years as a threshold, this biomarker had high sensitivity (0.84) and moderate specificity (0.53) as a predictor for dental fluorosis. The high positive predictive value indicates that fingernail fluoride concentrations should be useful in public health research, since it has the potential to identify around 80% of children at risk of developing dental fluorosis.