RESUMEN
UNLABELLED: Few reports have investigated caries prevalence in rural areas of Brazil. OBJECTIVE: The aim of this study was to observe the caries prevalence (DMFT, DMFS) in 12-year-old children living in rural villages of Paraíba, Brazil with low and moderate fluoride levels in the drinking water and to relate it to sugar intake and oral hygiene. METHODS: One hundred and ninety four children from 13 villages were grouped according to the water fluoride levels: low fluoride (LF, <0.2 ppm F, 96 children) and moderate fluoride (MF, 0.7-1.0 ppm F, 98 children). Caries and oral hygiene (OHI-S) were scored according to WHO criteria. Sugar intake was assessed through interviews. A sub-set of subjects (n=23) from the LF group was re-examined 2 years later. RESULTS: For the LF and MF groups the DMFT (mean, SD) observed was 3.9 (3.7) and 2.5 (2.1) respectively, the DMFS was 9.2 (10.6) and 5.4 (5.7). Both indexes (DMFT, DMFS) showed significant differences (P<0.01, Mann-Whitney U-test) according to the fluoride levels in the drinking water. The mean increment of caries in the sub-set group of subjects was approximately 1.5 surfaces per subject/year. The reported sugar intake was low for both water fluoride groups (P>0.05). In a regression analysis the water fluoride levels, the use of fluoridated toothpaste and oral hygiene index were related to DMFS (R2=0.08, P< or =0.05). CONCLUSIONS: Caries prevalence was lower in MF than in LF rural areas of Paraíba. Caries and sugar intake seems to be lower in rural areas than in urban areas of Paraíba with similar fluoride levels in the drinking water.
Asunto(s)
Caries Dental/epidemiología , Fluoruración , Brasil/epidemiología , Niño , Índice CPO , Caries Dental/etiología , Dieta Cariógena , Sacarosa en la Dieta/administración & dosificación , Fluoruros/administración & dosificación , Humanos , Higiene Bucal/estadística & datos numéricos , Índice de Higiene Oral , Prevalencia , Análisis de Regresión , Salud Rural , Estadísticas no ParamétricasRESUMEN
This work was based on the hypothesis that fingernail clippings can be used as a biomarker for the subchronic exposure to fluoride. The results provide data on factors that may affect the concentration of fluoride in fingernail clippings as determined with the electrode following HMDS-facilitated diffusion. The following variables had only minor or no effects on the concentrations: (1) the surface area of the clippings (intact, minced or filed into powder) that were placed into the diffusion dishes; (2) soaking in deionized water for up to 6 h; (3) soaking in fluoridated water (1.0 ppm) for 2 h, and (4) removal of the organic material of nails by dry ashing. Fingernail fluoride concentrations were approximately 50% higher than those in toenails. A 1-month period of increased fluoride intake by one of the authors resulted in significant increases in fingernail fluoride concentrations after a lag time of approximately 3.5 months. The fluoride concentrations in fingernail clippings obtained from three groups of Brazilian children were directly related to the concentrations in the drinking water (0.1, 1.6 or 2.3 ppm). The results indicate that: (1) HMDS-facilitated diffusion completely separates fluoride from intact nail clippings, so the need for ashing or other preparative methods is obviated; (2) fingernail fluoride is derived mainly from the systemic circulation, and (3) fluoride intake is reflected by the concentrations in fingernails.