OBJECTIVES: There is a lack of evidence on the proportion and severity of fluorosis in adult populations exposed and not exposed to fluoridated water over their lifetimes. The aim of this study was to compare the proportion and severity of fluorosis in adults with lifetime exposure to water fluoridation with a nonexposed sample. A secondary aim was to report the gradient of fluorosis severity by age.
METHODS: A cross-sectional study recruited a sample with lifetime exposure to water fluoridation and a matched, nonexposed group. 580 participants, aged 18-52 years (mean 34.3, SD 9.4) and 64% female, were recruited in general dental practices located in fluoridated (Birmingham and County Durham) and nonfluoridated areas (Manchester). Three digital images were taken of their incisors and an experienced examiner who was blind to exposure status viewed the images remotely and allocated fluorosis scores using the Thylstrup and Fejerskov (TF) scale.
RESULTS: At TF 1 (any fluorosis), a significantly higher proportion of participants from the fluoridated area had fluorosis (F 39% NF 21.3%, P < 0.001), at the threshold TF 3 (“aesthetic concern”), the difference was no longer statistically significant (F 4.1%, NF 2.2%, P = 0.25). There was a gradient by age, whereby fluorosis was highest in the youngest and lowest in the oldest age group.
CONCLUSIONS: Although fluorosis is more common in adults with lifetime exposure to water fluoridation than those with no exposure, the aesthetic impact of fluorosis seems to diminish with age.
The study was funded by Public Health England. Thanks go to John Morris for assistance with study design, David Landes and Janet Clarke for identification of practices; also to all participating dental practices: Castle Vale Dental, mydentist–Consett, Stanley Dental, DCO Dental and Windsor Dental. The views expressed are those of the authors and not necessarily those of Public Health England or the National Health Service. The University of Manchester acted as the sponsor. Prof. Pretty is the co-director of the Dental Health Unit that receives funding from the Colgate Palmolive Company.
CONFLICT OF INTEREST
The other authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article.