A theory-guided school-based intervention in order to improve adolescents' oral self-care: a cluster randomized trial

To evaluate the efficiency of social-cognitive theory-guided oral hygiene interventions in adolescents and to identify predictors of adolescents' self-care practice.

A cluster randomized trial included 197 15- to 16-year-olds from two secondary schools. The intervention group received three face-to-face educational hands-on sessions facilitated by a dentist and adolescents worked in pairs. Individual dental plaque levels were measured at baseline, after intervention, at six and at 12 months. The structured questionnaire inquired about gender, family socio-economic status (baseline), and different social-cognitive domain variables (baseline, six, and 12 months).

At baseline, there were no statistically significant differences in dental plaque scores between the intervention and control groups (P = 0.183). At the 6-month follow-up, the intervention group had significantly less dental plaque than the control group (P = 0.047), but the intergroup difference in dental plaque levels was not significant at the 12-month follow-up (P = 0.400). 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.

Social-cognitive theory-guided interventions improved oral self-care of adolescents in the short term. After the intervention was discontinued, the improvement in oral self-care of adolescents lasted for another 5 months.