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

Objectives : To explore the associations between dental behaviours and quality of life/caries experience, model the influence of dental behaviours on these outcomes across socioeconomic status (SES). Participants : 879 adults aged 45 to 54 from metropolitan Adelaide, South Australia. Research design : Data on SES (household income) and dental behaviours—including frequency of tooth brushing, mouth rinsing, interdental cleaning, dental visiting and self-care practices—were collected via questionnaire. Clinical examinations were completed for 709 participants to assess caries experience using the decayed, missing, and filled teeth (DMFT) index. Main outcome measures : Quality of life, extrapolated using the 14-item Oral Health Impact Profile (OHIP-14), and caries experience via DMFT scores. Results : An inverse SES gradient was observed for both quality of life and caries experience. Lower-income participants had reduced dental visiting scores [17.5 (95% CI: 17.1–18.0)] versus higher-income groups [20.0 (95% CI: 19.6–20.4)], and slightly 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 more likely to have visited a dentist in the last 12 months (39.5%) and to brush daily (36.9%) than lower-income individuals (29.7% and 30.0%, respectively). Full behavioural adjustment significantly 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 in 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 : Comprehensive dental behaviours can reduce socioeconomic inequalities in quality of life, but minimally impact caries experience.