A study of children aged 11 to 13 year old children in non-fluoridated Manchester and fluoridated Newcastle found low levels of dental fluorosis of aesthetic concern in both cities.  The prevalence was 1.2% for Manchester (based on a sample of 869 children) and 7.1% for Newcastle (based on a sample of 906 children). (1)

Just under half of the Newcastle children and around three quarters of the Manchester children were found to have no fluorosis at all.  Of those with fluorosis, the vast majority had questionable or very mild varieties below the threshold for aesthetic concern (generally regarded to start at a score of TF3 and above on the nine point TF scale).

Only three cases of severe fluorosis – two in non-fluoridated Manchester and one in

fluoridated Newcastle – were identified.  No case was rated at scores of TF6 to TF9.

Of the small minority with fluorosis of possible aesthetic concern, most cases were classified by the authors of the report as ‘mild’ (TF3 score).  The scores were based on blind examination of photographs of teeth, which meant the experts scoring the levels of fluorosis did not know which city the children came from.

Mild fluorosis is characterised by pearlescent white areas covering part of the tooth surface and making the teeth look whiter than usual.  It may or may not be noticed by the children concerned or their families and friends.

This study, published in 2012, is the most recent UK study to have appeared in the scientific literature.  For reasons which are unclear, it was not included in the 2015 Cochrane Oral Health Group systematic review of water fluoridation studies.

1. McGrady MG, Ellwood RP, Maguire A, Goodwin M, Boothman N (2012): The association between social deprivation and the prevalence and severity of dental caries and fluorosis in populations with and without water fluoridation.  BMC Public Health 12:1122.