RESUMO
DESIGN: Cluster randomised controlled trial. INTERVENTION: Clusters of adolescents (classrooms of 15- to 16-year-olds) in each school were allocated either into a control group or into an intervention group. The interventions consisted of peer cooperation (peer support) and peer interactive learning (observational learning) facilitated through feedback from a dentist (professional support). Three intervention sessions with preselected pairs of adolescents were delivered in the first three weeks. Gender, family socio-economic status (baseline) and different social-cognitive domain variables (baseline, six, and 12 months) were assessed using a questionnaire. OUTCOME MEASURE: Dental plaque levels were the primary outcome measure and they were measured at baseline, after the intervention measured only in the social-cognitive theory-guided group, at six and 12 months. RESULTS: At the six-month follow-up there was a statistically significant difference in means ± SD between the social-cognitive intervention group (27.4 ± 19.4) and the control group (35.1 ± 20.0). At the 12-month follow-up, there was no statistically significant difference in means ± SD between the social-cognitive intervention group (27.4 ± 18.5) and the control group (31.9 ± 17.8). Variations in dental plaque levels at different time periods were explained by the following predictors: family's socio-economic status, social-cognitive domain variables, group affiliation and baseline plaque levels. CONCLUSIONS: Social-cognitive theory-guided interventions improved oral self-care of adolescents in the short term. This improvement lasted only for five months after the intervention was discontinued.
