Oral health related behaviour We explore the role psychological theory can play in the understanding of health behaviours and the development of interventions to enhance oral health through behaviour change. Oral health is critically dependent upon the individual engaging in key behaviours such as tooth brushing and interdental cleaning. There is extensive evidence to suggest that theory-based interventions are superior to interventions not based on theory. We have reviewed and developed novel brief interventions for improving oral health related behaviours. This work formed the basis of our contribution to the development of the most recent guidelines of the European Federation of Periodontology.