The 2003 survey was based on a representative sample of children aged 5, 8, 12 and 15 years of age, attending government-maintained and independent schools in the UK. A total of 12,698 children were sampled from participating schools and asked to take part in a dental examination at school. In total 10,381 children were examined – a response rate of 82 per cent. Questionnaires requesting background data on children's oral hygiene and dental care were sent to the parents of a random sub-sample of 5,480 examined children. In total, 3,342 questionnaires were returned – a response rate of 61%.