Autonomy-supportive dental treatment, oral health-related eudaimonic well-being and oral health: a randomized clinical trial.

We tested the hypotheses that a dental intervention designed to promote oral care competence in an autonomy-supportive way, relative to standard care, would positively predict patients' perceived autonomy support from oral health-care professionals, increases in eudaimonic well-being (i.e. both personal growth and purposeful behaviour goals) and improved oral health (i.e. reduced dental bacterial plaque on tooth surface and reduced gingivitis) over 5.5 months. We also tested a self-determination theory model with the intervention positively predicting perceived autonomy support, which in turn would predict increases in eudemonic well-being, leading to improved oral health. A randomised two-group experiment was conducted at a dental clinic with 138 patients ( = 23.31 yr,  = 3.5). Variables were measured before and right after the intervention and 5.5 months later. Overall, the experiment and hypothesised process models received strong support. The effect sizes were large for perceived autonomy support, change in personal growth, change in dental plaque and change in gingivitis, whereas the effect size for purposeful behaviour was moderate. The measurement and structural equation models for the SDT process model received good fit. The current field experiment extends previous knowledge by showing that promoting patient oral care competence in an autonomy-supportive way improves oral health through patients' eudaimonic well-being.