Fluoride varnish is a non-aqueous form of topical fluoride and was developed in the 1960s to promote a longer retention of the fluoride agent on tooth surfaces (Chu and Lo, 2006). It is quick and easy to apply directly onto tooth surfaces with a mini-brush. It adheres to tooth surfaces even in the presence of saliva. Several compounds, including difluorosilane and sodium fluoride, have been used at different concentrations, but the moststudied varnishes contain 5% sodium fluoride in an alcoholic
solution of natural varnish substances.