Saied‐Moallemi 2009

Methods	Study design: cluster‐randomised controlled trial Conducted in: Iran Unit of randomisation: school Unit of analysis: individual Setting: urban area Funded by: "Financial support was provided by the Iran Center for Dental Research (ICDR)" Duration of the study: 3 months
Participants	Inclusion criteria: unclear Exclusion criteria: unclear Age at baseline: not reported (9‐year‐olds) N (controls baseline): 117 N (controls follow‐up): 116 N (interventions baseline) Group 1: 115 Group 2: 114 Group 3: 111 N (interventions follow‐up) Group 1: 110 Group 2: 112 Group 3: 109 Recruitment: through schools Gender: Each group included 2 boys’ schools and 2 girls’ schools
Interventions	Interventions Group 1. Class‐work group. This intervention was applied in class by means of 7 various illustrative puzzles printed on A4 sheets, used as learning tools, including oral health messages guiding children to twice‐daily toothbrushing and use of fluoride toothpaste Group 2. Parental‐aid group. This intervention was provided by parents at home without additional instructions on oral health at school. A 2‐page A4‐size oral health leaflet and a brushing diary together with a cover letter prepared for the study were delivered by health counsellors to children to take home Group 3. Combined group. Intervention in this group was carried out both via class‐work and by parents according to the programmes described above Control: This group received no intervention but underwent clinical examination and completed the questionnaire Duration of intervention: 3 months
Outcomes	Changes in gingival bleeding index and plaque index
Implementation related factors	Theoretical basis: not reported Resources for implementation: clinical examinations, questionnaire, class‐work group, parents' intervention, puzzles and class‐based education sessions, oral health leaflets and use of fluoridated toothpaste Who delivered the intervention: dentist, home‐base parents, teachers PROGRESS categories assessed at baseline: not reported PROGRESS categories analysed at outcome: not reported Outcomes related to harms/unintended effects: not reported Intervention included strategies to address diversity or disadvantage: not reported Economic evaluation: not reported
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of sequence generation were not described – clusters were not randomly assigned
Allocation concealment (selection bias)	Low risk	All clusters were randomised at the same time
Incomplete outcome data (attrition bias) All outcomes	Low risk	Numbers excluded from analysis are low and similar in each group. Reasons for missing outcome data are unlikely to be related to true outcomes
Selective reporting (reporting bias)	Unclear risk	Unclear
Other bias	Unclear risk	Unclear
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Article states: "To avoid bias, the details of the interventions were not explained to the children”
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Baseline clinical examinations were conducted by 1 of the study authors – it is unclear whether the baseline examiner was blinded. Post‐intervention examinations were carried out by a separate dentist ‐ a dentist not involved in study procedures and blinded to group assignment. Calibrations between examiners were carried out