Role of social class in caries occurrence in primary teeth.

The independent effect of social class on (A) the risk of having any caries (deft greater than or equal to 1) and on (B) the risk of having a few caries defects (deft greater than or equal to 3) in primary teeth was studied. The data, which were representative for all Finnish children of this age group, were collected by questionnaires from health centres and homes for 1637 children aged 2.5 to 7.5 years. The response rate was 83%. According to logistic regression analyses, children in the upper social class were clearly at lower risk of having caries than were children in the middle social class, independent of the child's age or sex, reported frequency of toothbrushing, consumption of sugar or use of fluoride tablets. In contrast, children in the lower social class had a higher risk of caries, which was independent of the reported dental health behaviour of the children. The results indicate that the differences among social classes in caries occurrence could not be eliminated by changes in dental health habits. Basic and applied research is needed to identify the relevant factors in socioeconomic status related to caries occurrence so that the differences in dental health between preschool children in different social classes can be reduced.