Triple-blind randomized controlled trial with two parallel arms conducted between 2012 and 2014. Children 2-3 years old, from 28 rural public preschools, located in low socioeconomic areas of Chile were invited to participate. Oral health education component was given to children, parents and educators, twice yearly. A new toothbrush and toothpaste for each child was delivered to the parents at baseline and in each of the follow-up visits. The experimental group was treated with fluoride varnish every six months while the control group received placebo applications. 277 preschoolers (2 to 3 years) Main outcome: Number of Caries Incident Cases, increment dmft index