Investigating the associations between oral health behaviours and outcomes,in the context of the social gradient in oral health

Objectives: To examine the associations between oral health behaviours, quality of life, and caries experience, and to assess the extent to which these behaviours account for oral health disparities across socioeconomic groups. Participants: 879 adults aged 45–54 years from metropolitan Adelaide, South Australia. Research design: Data on socioeconomic status (SES, via household income), oral health behaviours (toothbrushing, mouth rinsing, interdental cleaning, dental visiting, and self-care) and quality of life were collected via questionnaire. Clinical examinations were completed for 709 participants to assess caries experience. Outcome measures: Quality of life, assessed via the 14-item Oral Health Impact Profile (OHIP-14), and caries experience via DMFT scores. Results: An inverse SES gradient was recognised for quality of life and caries experience. Lower-income participants had reduced dental visiting scores [17.5 (95% CI: 17.1–18.0)] than higher-income groups [20.0 (95% CI: 19.6–20.4)], and higher dental self-care scores [17.7 (95% CI: 17.3–18.0)] than mid-income participants [17.6 (95% CI: 17.2–18.0)]. Higher-income individuals were likelier to have visited a dentist in the last 12 months (39.5%) and brush daily (36.9%) than lower-income individuals (29.7% and 30.0%). Full behavioural adjustment attenuated SES disparities in quality of life (unadjusted β = −2.7, 95% CI: −3.4 to −2.1; adjusted β = −2.0, 95% CI: −2.7 to −1.3), but not caries experience (unadjusted β = −0.8, 95% CI: −1.3 to −0.3; adjusted β = −0.7, 95% CI: −1.2 to −0.1). Conclusions: Oral health behaviours were associated with reduced socioeconomic inequalities in quality of life. Insignificant associations were observed between oral health behaviours and caries experience, even after adjustment for SES.