Interdental brushing behaviour in adults: Influence of periodontal status and socioeconomic factors.

AIM: To evaluate patterns of interdental brush (IB) use across different stages and grades of periodontitis and to examine associations with socioeconomic, demographic, and behavioural factors. METHODS: This cross-sectional study included 375 adults referred for secondary periodontal care at Guy's and St Thomas' Hospital (London, UK). Periodontal status was classified using the 2018 periodontal classification. Participants completed a 10-item questionnaire on IB use and perceived barriers. Area-level household income was estimated using postcode-linked national statistics. Associations were analysed using chi-squared tests and multivariable logistic and ordinal regression models. RESULTS: Daily IB use (63.0%) was significantly associated with periodontitis stage (p<0.001) but not grade. Patients with Stage III-IV periodontitis had higher odds of daily IB use (OR=3.11, 95% CI 1.88-5.15, p<.001). Higher income and older age were positively associated with IB use, while current smoking was a strong negative predictor (OR=0.31, 95% CI 0.15-0.67). Common barriers included pain, discomfort, and cost. CONCLUSIONS: A distinct profile of periodontal patients who are less likely to use IBs regularly was characterised by early-stage disease, younger age, lower income, and current smoking status. Dissatisfaction driven by practical, financial, and environmental concerns highlights the need for tailored preventive advice and personalised interdental cleaning strategies to improve adherence.