BACKGROUND:
Early Childhood Caries is highly prevalent in South Africa, with parental oral health practices contributing to risk. Behavioral theory-based interventions may strengthen parental cognition and improve children’s toothbrushing. This study evaluated whether a Theory of Planned Behavior (TPB)-anchored intervention improved parents’ cognitive predictors and reported toothbrushing frequency for their children.

METHODS:
A single-blinded cluster randomized controlled trial was conducted at two socio-economically comparable community health centers in Johannesburg. Parent-child pairs with children aged six months to two years were recruited. The intervention included a 30-minute oral health education session, toothbrush and toothpaste provision, an information booklet and weekly educational SMSs for three months. The control group received only the booklet. Cognition, which included, attitudes, subjective norms, perceived behavioral control and intention was assessed. In addition, toothbrushing frequency examined at baseline and three months using a validated questionnaire.

RESULTS:
A total of 171 participants completed follow-up. Both groups showed improvements in cognition and toothbrushing frequency, but gains were consistently greater in the intervention group. Perceived behavioral control declined in the control group and toothbrushing frequency correlated positively with all cognitive constructs except intention.

CONCLUSIONS:
A TPB-based intervention combining in-person education and SMS reinforcement improved parents’ cognition and children's toothbrushing frequency more effectively than traditional education alone. Integrating behavioral theory with digital reinforcement and basic oral hygiene support may strengthen parental capacity to maintain children’s oral health.