Socio-economic inequality in the self-reported number of natural teeth among Norwegian adults--an analytical study

To assess inequality in dental status associated with educational level, gross personal and family income among Norwegian adults.

Data were collected by Norway's Central Bureau of Statistics in November-December 2003. A two-stage, proportional random sample comprising 2000 persons aged 16-79 years was drawn from the national population register. Information became available for 1309 subjects by interview. The present analyses pertain to 1092 subjects aged 25-79 years (response rate 66%, mean age 47.9 years).

Of the respondents, 3% were edentulous and 9% had fewer than 20 teeth. The mean number of teeth was 27.1 (SD 7.0). In multiple logistic regression analysis, low gross personal and adjusted family income were associated with increased likelihood of having fewer than 20 natural teeth (OR = 2.84, 95% CI 1.58, 5.10; OR = 3.63, 95% CI 1.99, 6.62, respectively). Educational level was significantly associated with dental status in bivariate but not in multivariate analyses, except once among males. The predictors of socio-economic inequality in dental status accounted for a limited proportion of explained variance (Nagelkerke's R(2)) when controlling for age, place of residence, perceived oral health compared with others, perceived importance of oral health, dental attendance and smoking.

Socio-economic inequality in dental status persists among Norwegians aged 25-79 years but absolute differences have decreased during the last 30 years. The findings are encouraging but challenging as far as choice of strategy for further reduction of differences in tooth loss.