Dental behaviour and social inequality in caries experience

Objectives: To investigate whether dental behaviour influences social inequality in caries experience. Methods: A random sample of 45-54 year-olds from Adelaide, South Australia was surveyed by self-complete questionnaire in 2004-05 (n=879, response rate=43.8%). Oral examinations were performed by calibrated dentists on 709 persons (completion rate=80.7%). Results: The mean±SE number of decayed teeth (D) was 0.4±0.04, with 5.3±0.2 missing teeth (M), and 11.0±0.2 filled teeth (F). The majority brushed their teeth 8+ times per week (78.8%) and had made a dental visit within the last 12 months (63.7%). Nearly a quarter had a household income of $30,000 or less (24.0%). Brushing 8+ times per week was associated with less D (0.3±0.03) and M (4.9±0.2) compared with less frequent brushing (0.8±0.1 and 6.5±0.5 respectively). Visiting within 12 months was associated with less D (0.2±0.03) and more F (11.7±0.2) compared with less frequent attendance (0.7±0.1 and 9.8±0.3 respectively). Low income was associated with more D (0.8±0.1) and M (6.6±0.4), but less F (9.8±0.4) compared to incomes of $60,000+ (0.2±0.03, 4.3±0.2 and 11.3±0.3 respectively). Multivariate analysis showed interactions (P<0.05, GLM) between income and brushing and between income and visiting for decayed teeth, showing that the relationship between decayed teeth and dental behaviour varied across levels of income. In the low income group those who brushed their teeth 8+ times per week had D=0.4±0.1 while those who brushed less often had D=1.4±0.3 compared to D=0.2±0.03 and D=0.2±0.1 respectively in the high income group. For dental visiting, in the low income group those who visited within 12 months had D=0.4±0.1 while those who visited less frequently had D=1.3±0.3 compared to D=0.1±0.02 and D=0.3±0.1 in the high income group. Conclusion: Dental behaviour in terms of brushing and visiting influenced social gradients in oral health for decayed teeth across income groups. Supported by NHMRC (#250316).