Eligible studies were randomised controlled trials and clinical trials that focused on the effects of fluoridated food on caries outcomes. Studies were excluded if fluoridated food was used in combination with one or more other types of fluoride delivery mechanisms or where fluoride supplementation was given indirectly (for example, during pregnancy).
Included studies were of fluoridated milk and fluoridated sugar (used as an ingredient in tea and porridge). Mean ages of participants ranged from 3.5 years to 19 years. Where reported, studies included approximately equal proportions of males and females. Intervention duration ranged from 18 to 21 months. Supplemental fluoride intake ranged from 0.38 to 0.58 mg per day.
Two reviewers independently selected the studies for inclusion. Disagreements were resolved by discussion and by involving two other reviewers if needed.