Song 2004

Methods	Study design: quasi‐experimental, controlled before‐and‐after study Conducted in: Korea Unit of randomisation: unclear Unit of analysis: children Setting: kindergarten Funded by: not disclosed Duration of the study: April 2001 to November 2001
Participants	Inclusion criteria: unclear Exclusion criteria: unclear Age at baseline: 5‐year‐olds attending kindergarten Total at baseline: 67 N (controls baseline): 34 N (controls follow‐up): not reported N (interventions baseline): 33 N (interventions follow‐up): not reported Recruitment: unclear Gender: Gender breakdown for boys was not reported, proportions of girls between both groups were similar
Interventions	Intervention: oral health education programme 20‐minute oral health education session once per week for 4 weeks Follow‐up after 28 weeks. Control: unclear Duration of intervention: 4‐week intervention period
Outcomes	Dmft and plaque index
Implementation related factors	Theoretical basis: not reported Resources for implementation: unclear Who delivered the intervention: unclear PROGRESS categories assessed at baseline: unclear PROGRESS categories analysed at outcome: unclear Outcomes related to harms/unintended effects: unclear Intervention included strategies to address diversity or disadvantage: unclear Economic evaluation: unclear
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Unclear
Allocation concealment (selection bias)	Unclear risk	Unclear
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear
Selective reporting (reporting bias)	Unclear risk	Unclear
Other bias	Unclear risk	Unclear
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Unclear
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unclear