Evaluación de fluoruro residual en saliva después de la aplicación de barnices fluorados al 2.26 por ciento: estudio comparativo / An evaluation of the residual fluoride in saliva after applying 2.26 per cent fluoride varnishes: a comparative study

El objetivo de este estudio fue comparar la cantidad de fluoruro (F) residual en saliva después de la aplicación de barniz de fluoruro desodio al 5 por ciento y de barniz fluorado con fosfato tricálcico al 5 por ciento en niños de 2 a 5 años de edad. Se recolectó la saliva no estimulada de 24 niños que tenían acceso a sal fluorada diariamente y utilizaban dentífricos infantiles conteniendo 550 ppm F. La primera toma de muestrasalival fue colectada como basal y las siguientes fueron tomadas en diferentes intervalos de tiempo luego de realizar la aplicación del barnizfluorado (15; 30; 60 minutos y 24; 48; 72; 96; 168 horas). Un total de 216 muestras fueron obtenidas, siendo 96 muestras de barniz de Duraphat®, 96 muestras de barniz de ClinproTM WV y 24 muestras muestras basales. Los análisis de laboratorio fueron realizadosen el departamento de Bioquímica de la Facultad de Odontología de Baurú (FOB), Universidad de Sao Paulo. Un electrodo Orión 9409 y un microelectrodo acoplados a un potenciómetro Orion EA 940 se utilizaron para analizar las muestras previa difusión de las muestrascon el método de Taves. La concentración de iones de flúor mostró diferencias estadísticamente significativas entre ambos productos desde las 24 horas (p<0.001), esta característica se repite a las 48 (p=0.003); 96 (p<0.001) y 168 horas (p<0.001). Se utilizó el análisisestadístico de Shapiro Wilks y T de Student. Ambos barnices mostraron un incremento de fluoruro residual en saliva durante los 15; 30 y 60 minutos, sin embargo, posteriormente a estos tiempos, ambos muestran niveles no significativamente diferentes al basal.

The aim of this study was compared the amount of residual fluoride after application of sodium fluoride varnish 5% and application offluoride varnish with phosphate tricalcium 5% in children from 2 to 5 years old. Unstimulated saliva was collected of 24 children who hadaccess to fluoridate salt daily and used children´s tooth pastes containing 550ppm F. The first salivary sample was collected as a base lineand the following were taken at different intervals after making the application of fluoride varnish (15; 30; 60 minutes; 24; 48; 72; 96;168 hours).Children were grouped in two groups according of type of varnish containing fluoride going to be applied. A total of 216samples were obtained, 96 samples from Duraphat® and 96 samples from ClinproTM WV 3M ESPE. The lab analyzes wereconducted in the Department of Biochemistry at the Faculty of Dentistry, Bauru (FOB), University of Sao Paulo. An Orion 9409electrode and a microelectrode coupled to a potentiometer Orion EA 940 analyzed the samples prior dissemination of samples with themethod of work. The fluoride concentration was statistically significant after 24 (p<0.001); 48 (p=0.003); 96 (p<0.001) y 168 hours(p<0.001) for both products. We used Shapiro Wilks and T student test for statistical analysis. Both products showed an increased inresidual fluoride in saliva during the 15; 30 and 60 minutes, however, both showed not differences that baseline levels.

Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice

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 µg 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.

As unhas têm sido consideradas um biomarcador para a exposição ao flúor (F), mas não há consenso se é um indicador confiável para exposição ao F a partir do dentifrício. Vinte e três crianças, com idade entre 1 a 3 anos, moradoras de Piracicaba (0,72 ppm F na água), Brasil, foram submetidas a duas fases de diferentes exposição ao F: fase A (1a a 11a semanas), as crianças foram expostas à combinação de F a partir da dieta (sólidos e líquidos) e dentifrício (1500 µg F/g como MFP); e na fase B (12ª a 29ª semanas), apenas ao F da dieta, uma vez que usaram dentifrício não fluoretado. As unhas das mãos foram coletadas semanalmente durante 35 semanas para determinação de F. A exposição ao F a partir da dieta e dentifrício foi também determinada. Ambas análises foram feitas com eletrodo específico para F. A exposição ao F foi significativamente maior (p<0,001) quando as crianças foram expostas ao F da dieta + dentifrício que ao F da dieta (0,086 ± 0,032 e 0,040 ± 0,009 mg F/kg corpóreo/dia, respectivamente). Entretanto, a concentração de F nas unhas coletadas durante todo o período experimental não diminuiu após a interrupção da ingestão do F a partir do dentifrício. Os resultados sugerem que as unhas das mãos não são um biomarcador confiável para refletir a exposição ao F pelo dentifrício.