Aim. The aim was to empirically test the extended Theory of Reasoned Action (TRA) and the prospective direct and indirect role of attitudes, beliefs, subjective norms, self-efficacy, and a cognitive behavioural intervention in adult's oral hygiene behaviour and gingival outcomes at 3- and 12-month follow-up.
Materials and Methods. Data were derived from an RCT evaluating the effectiveness of oral hygiene educational programs integrated in non-surgical periodontal treatment (n = 113). Before baseline examination, participants completed a self-report questionnaire. Structural equation modelling using maximum likelihood estimation with bootstrapping was used to test the direct and indirect (mediated) pathways within the extended TRA model.
Results. The extended TRA model explained a large amount of variance in gingival outcome scores at 12 months (56%). A higher level of self-efficacy at baseline was associated with higher frequencies of oral hygiene behaviour at 3 months. Being female was linked to more normative beliefs that, in turn, related to greater behavioural beliefs and self-efficacy. Gender was also related to behavioural beliefs, attitudes and subjective norms. Both frequency of oral hygiene behaviour at 3 months and the cognitive behavioural intervention predicted gingival outcome at 12 months.
Conclusions. The model demonstrated that self-efficacy, gender and a cognitive behavioural intervention were important predictors of oral hygiene behavioural change.