Considerable resources are expended in dealing with dental disease easily prevented with better oral hygiene. The study hypothesis was that an evidence-based intervention, framed using psychological theory, would improve patients’ oral hygiene behaviour. The impact of trial methodology on trial outcomes was also explored by conducting two independent trials, one randomised by patient and one by dentist. The study included 87 dental practices and 778 patients (Patient RCT = 37 dentists / 300 patients; Cluster RCT = 50 dentists / 478 patients).

Controlling for baseline differences, pooled results showed patients who experienced the intervention had better behavioural (timing, duration, method), cognitive (confidence, planning), and clinical (plaque, gingival bleeding) outcomes. However, clinical outcomes were only significantly better in the Cluster RCT, suggesting the impact of trial design on results needs to be further explored.





Clarkson JE, Young LV, Ramsay CR, Bonner BC, Bonetti D. How to influence patient oral hygiene behaviour effectively.  Journal of Dental Research 2009; 88(10): 933-937