Riordan 2002.

Methods	FLUOROSIS STUDY Country of study: Australia Geographic location: Western Australia Year of study: 2000 Year of change in fluoridation status: NA Study design: Cross‐sectional
Participants	Inclusion criteria: Children born around 1990 (10 yrs old) who had lived in Australia/New Zealand for most of their lives (so as to ensure life time exposure to water fluoridation) Exclusion criteria: Migrants from outside Australia and New Zealand, refusal to consent, not present at school at the time of exam Other sources of fluoride: Information was collected on use of infant formula, age at which toothpaste was introduced and the use of fluoride supplements. Fluoride supplement use was almost exclusive to residents of the non‐fluoridated areas Social class: Not specified Ethnicity: Not specified Residential history: Participants were categorised as having been exposed to water fluoridation if they had spent more than half their life between the ages of 0‐5 in a water fluoridated area Other confounding factors: Not specified
Interventions	Group 1: 0.8ppm (artificial fluoridation) Group 2: 0.2‐0.3 ppm (naturally fluoridated)
Outcomes	Dental fluorosis (TF index) Age at assessment: 10 years
Funding	Not stated
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Sampling	Low risk	The sampling frame was made up of children registered with the School dental service and children were accessed via schools. All eligible children were invited to take part in the study
Confounding	High risk	Information on other sources of fluoride was collected and more children in the non‐fluoridated area took fluoride supplements. SES was not stated.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Insufficient information
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data presented for all participants
Selective reporting (reporting bias)	Low risk	Outcome of interest reported
Other bias	Low risk	No other apparent bias