Caries patterns in an urban preschool population in Norway.

AIM This was to describe the prevalence, severity and distribution of caries in a preschool population in Oslo, Norway, and to compare the findings in subgroups according to immigrant status and age. Furthermore, the present data should serve as a baseline for longitudinal studies. METHODS The participating children (n = 775), chosen from 7 clinics in the Public Dental Health Service, were of various socioeconomic backgrounds and immigrant status (IM, immigrant group-mother of non-western origin or WN, western native group-mother of western background). The study design was descriptive cross-sectional. The caries examinations were carried out by calibrated examiners, and a detailed 5-graded caries diagnosis system including incipient caries was used. Radiographs (BW) were taken of the 5-year-old children. RESULTS The percentage of caries free children, aged 3 years (mean 3.0) and 5 years (mean 4.8) were 80.1% and 48.0% respectively. The subgroup of immigrant children showed a considerably higher caries prevalence, it was more often affected by severe caries and experienced an earlier onset of the disease than the subgroup of western native children. The most marked skewness of the caries data was seen within the WN group, especially at 3 years of age. CONCLUSIONS The present study has revealed disparities in dental health associated with ethnic origin seen at the age of 3. The disparities in dental health are still evident at 5 years of age, but then caries is more common for the whole population.