Extended caries prevention programme with biannual application of fluoride varnish for toddlers: prevalence of dental fluorosis at ages 7-9 years and associated factors.

OBJECTIVE: To investigate the prevalence of and factors associated with dental fluorosis in children living in areas of high caries risk in Stockholm and who had participated in a prospective, parallel, cluster-randomized, controlled caries prevention trial between ages 1 and 3 years. MATERIALS AND METHODS: The study group comprised a random sample of the children who had completed the 2-year prevention trial (n = 2536) in 2011-2014. All children were instructed to use fluoride toothpaste; the test group received fluoride varnish applications twice a year. Dental fluorosis prevalences in the reference (n = 220) and the test (n = 234) groups were compared. Presence of fluorosis was determined using the Thylsturp & Fejerskov (TF) index on photos of the permanent maxillary incisors. RESULTS: No significant difference in dental fluorosis was observed between the two groups. Nearly one-third (29.7%) of the children in the study cohort exhibited dental fluorosis (TF index >/= 1). Associations with use of fluoride toothpaste at age 1 year and with socioeconomic status factors were found. CONCLUSIONS: Biannual applications of fluoride varnish in toddlers was not associated with dental fluorosis, which when found was rarely of aesthetic concern. Parental education in tooth-brushing routines is recommended.