Effectiveness of fluoride varnish in preventing early childhood caries in rural areas without access to fluoridated drinking water: A randomized control trial.

OBJECTIVES: Early childhood caries (ECC) constitutes a serious public health issue, especially in communities without water fluoridation. We assessed the effectiveness of biannual fluoride varnish applications to prevent ECC in children from nonfluoridated rural areas. METHODS: A triple-blind randomized control trial with two parallel arms was conducted with 275 two- to three-year-old children without cavitated carious lesions from 28 rural public preschools in Chile. The preschools were located in areas of low socioeconomic status without access to fluoridated water. An oral health education component was administered to children, parents and educators. A new toothbrush and toothpaste for each child was delivered to the parents at baseline and at four follow-up visits. The participants were randomly allocated to receive fluoride varnish or placebo applications every six months. Trained, calibrated dentists blind to the treatment arm performed visual dental assessments at 6, 12, 18 and 24 months. The primary endpoint was the development of cavitated carious lesions in children during the 24-month follow-up period using WHO criteria, and the secondary outcomes were an increase in caries measured as a change in the index of decayed, missing or filled teeth (dmft) since the beginning of the study and the development of adverse effects. An intention-to-treat (ITT) approach was used for the primary analysis. RESULTS: We included 131 participants in the intervention group and 144 participants in the placebo group; of these children, 89 (67.9%) in the intervention group and 100 (69.4%) in the control group completed the protocol. The comparative ITT analysis of caries incidence after 24 months of follow-up showed a between-group prevention fraction of 18.9% (-2.9%-36.2%). Caries incidence was 45.0% for the experiment group and 55.6% for the control group (P = .081), with a mean dmft of 1.6 (SD = 2.4) and 2.1 (SD = 2.5), respectively. No adverse effects were reported. CONCLUSIONS: In conclusion, biannual fluoride varnish application is not effective in preschool children from rural nonfluoridated communities at a high risk of caries.

Disponibilidad de Flúor en Saliva y Biofilms en Escolares Expuestos a Leche o Agua Fluorurada / Availability of Fluoride in Saliva and Biofilms in School Children Exposed to Fluoride in Water or Milk

La caries sigue siendo un problema de Salud Pública, por la alta prevalencia y severidad que afecta a la población. En Chile, la incorporación de flúor en el agua y la leche, son medidas de salud pública en la prevención de caries que se distribuye en zonas urbanas y rurales respectivamente. La evidencia científica nos permite sostener que el fluoruro disponible en saliva y placa bacteriana es el principal responsable del efecto preventivo de este compuesto en el proceso de caries. El objetivo fue comparar los niveles de flúor en saliva y placa bacteriana, antes y después de la ingesta de leche, de los escolares que consumen leche fluorurada y de los que consumen leche sin flúor preparada con agua potable fluorurada de la Región de la Araucanía de Chile. Se realizó un estudio de muestras repetidas de saliva y placa bacteriana en 165 niños(as) incorporados(as) en el Programa PAE de 16 escuelas rurales y urbanas. Se tomaron muestras de saliva y placa bacteriana antes del desayuno, muestras de saliva 60 min después y muestras de placa bacteriana 120 minutos después del desayuno. La concentración de fluoruro en saliva se observa muy similar sin importar el vehículo a través del cual se le administre, sea este leche fluorurada o leche sin fluor preparada con agua fluorurada, tanto en las muestras basales como en las muestras obtenidas después del desayuno. En cambio en placa bacteriana si se observan pequeñas diferencias que, siendo estadísticamente significativa, pueden no tener mucha relevancia clínica por ser demasiado pequeñas. Estos resultados refuerzan la hipótesis de que la estrategia de leche fluorurada tiene resultados similares al agua fluorurada.

Caries continue to be a public health problem, due to their high prevalence and their severe effect on people. Currently in Chile, adding fluoride to water and milk are public health measures to prevent caries that are distributed in urban and rural areas respectively. Scientific evidence supports the availability of fluoride in saliva and bacterial plaque being the most effective prevention against caries. The goal was to compare the levels of fluoride in saliva and bacterial plaque before and after drinking milk, among school-children who consume fluoridated milk and those who consume un-fluoridated milk prepared with fluoridated drinking water, in the La Araucanía Region of Chile. A study was conducted of repeated samples of saliva and bacterial plaque in 165 children within the PAE program at 16 rural and urban schools. Saliva and bacterial plaque samples were taken before breakfast, saliva samples were taken 60 minutes after breakfast and bacterial plaque samples were taken 120 min after breakfast. The concentration of fluoride in saliva was found to be very similar regardless of the manner in which it was administered. So it was similar in children drinking fluoridated milk and un-fluoridated milk prepared with fluoridated water, and similar both before and after breakfast. In contrast, we found small differences for bacterial plaque, that are statistically significant. However, they may not be clinically significant as they are too small. These results reinforce the hypothesis that the strategy of adding fluoride to milk has similar results to adding fluoride to water.