3. Suggested trial design.

Method	Allocation: randomised, clearly described Blinding: double blinded, described and tested Duration: 6 months
Participants	Diagnosis: thought to have psychoses N = 300* Age: any Sex: both male and female History: acutely ill, aggressive
Intervention	1. Oral health education (advice and training) 2. Monitoring 3. Treatment as usual
Outcomes	Specific behaviours: self harm, including suicide, injury to others, aggression Global outcomes: overall improvement, use of additional medication, use of restraints/seclusion Service outcomes: duration of hospital stay, re‐admission Mental state: no clinically important change in general mental state Adverse events: clinically important adverse events Leaving the study early: reason Economic outcomes
Notes	*Powered to be able to identify a difference of ˜20% between groups for primary outcome with adequate degree of certainty