Fluoride Varnish Applications in Preschoolers and Dental Fluorosis in Permanent Incisors: Results of a Nested-cohort Study Within a Clinical Trial

Purpose: To compare the prevalence and severity of fluorosis in the permanent maxillary incisors of children who had participated in a two-year randomized placebo-controlled clinical trial on fluoride varnish application in the primary dentition and to assess children's esthetic perception of their teeth. Methods: Parents of 200 one- to four-year-old children who had received biannual applications of fluoride or placebo varnish were contacted four years after the end of the trial. Two calibrated examiners assessed dental fluorosis using the Thylstrup and Fejerskov index (TF) and interviewed the children regarding their perceptions of teeth appearance. Results: Fluorosis (TF equals at least one) and esthetically objectionable fluorosis (TF equals at least three) were observed in 38 (30.9 percent) and eight (6.5 percent) children, respectively. There was no statistically significant difference in fluorosis prevalence between children who had received fluoride or placebo varnish. Children's responses regarding the esthetic perceptions of their teeth showed no statistically significant difference between children with and without fluorosis. Conclusions: Fluoride varnish applications in preschoolers were not associated with any level of fluorosis in their permanent maxillary incisors. The fluorosis found in this study did not influence the children's esthetic perception of their teeth.