The ADA has performed several systematic reviews of the literature on F-varnish efficacy for caries protection and has concluded that there is sufficient evidence to recommend twice a year use of F-varnish for children who are at moderate and high caries risk. Application of F-varnish at six month intervals is recommended for caries prevention in permanent teeth. Children who are not at caries risk may not benefit from F-varnish applications; however, the risks from the therapy are negligible and the benefits have been judged to outweigh the risks. The most recent systematic review on topical fluoride indicates that the evidence favors F-varnish applications at least every three to six months for all children younger than 18 years of age.12 This same review found that the evidence is lacking for use of F-varnish for adults 18 and older or for prevention of root caries, however, expert opinion is in favor of these uses to prevent caries.