Changing oral health status of 6- and 12-year-old schoolchildren in Portugal.

To assess the actual oral health status of Portuguese schoolchildren aged 6 and 12 years according to gender and urbanisation, to highlight the trend over time in dental caries prevalence of children, to assess the dental care habits and the provision of preventive services to children, and to analyse the effect of dental care habits on caries experience. Clinical examinations of oral health status were carried out in 1999 according to WHO criteria and included dental caries, enamel lesions, oral hygiene status (OHI-S) and Community Periodontal Index (CPI). Structured questionnaires for interviewing children on dental care habits and participation in preventive programmes at school were used. The study comprised 799 6 year olds and 800 12 year olds. In 1999, the prevalence proportion rates of dental caries were 46.9% in 6 year olds and 52.9% in 12 year olds. Dental caries experience was 2.1 dmf-t and 1.5 DMF-T, respectively. Significant reductions in caries prevalence rates took place over time; in 1984 the mean dmf-t of 6 year olds was 5.2 and for 12 year olds it was 3.7 DMF-T. Enamel opacities were found for 7.2% of children and 2.1% had moderate dental fluorosis. At age 12, 90% of children had poor oral hygiene, i.e. CPI Score 2 (bleeding and calculus). Toothbrushing twice a day was reported for 31% of 6-year-olds and 55.6% of 12-year-olds; 17.8% of children aged 6 had seen a dentist during the past year and this was found to be 58.3% at age 12. Substantial proportions of the children received preventive dental services in school. Multivariate analysis of dental caries experience showed that gender, location, nationality, dental visits and frequency of toothbrushing were significant independent variables. Further implementation of school based oral health promotion and application of population-directed preventive strategies are needed in Portugal.