Özen 2012.

Methods	Parallel design Funding: not stated Location: Turkey
Participants	Inclusion criteria: ASA 1; children with definitely or slightly negative behaviour ratings on the Frankl Behaviour Rating Scale and who had prior experience with sedation or general anaesthesia n = 240, 116 girls, 124 boys Age range = 4 to 6 years
Interventions	Group 1 (n = 60): midazolam (0.20 mg/kg) (40 mg/ml) intranasally, inhalation sedation 50%/50% nitrous oxide/oxygen Group 2 (n = 60): midazolam (0.75 mg/kg) (15 mg/3 ml) orally, inhalation sedation 50%/50% nitrous oxide/oxygen Group 3 (n = 60): midazolam (0.50 mg/kg) (15 mg/3 ml) orally, inhalation sedation 50%/50% nitrous oxide/oxygen Group 4 (n = 60): inhalation sedation 50%/50% nitrous oxide/oxygen
Outcomes	Bispectral Index System; modified scale to classify behaviour; Vancouver Recovery Scale
Notes	Restraint used
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding ‐ Participant	Unclear risk	Not described
Blinding ‐ Operator/sedationist	Unclear risk	Not described
Blinding ‐ Outcome assessor	Unclear risk	Not described
Incomplete outcome assessment	High risk	Difficult to gather if dropouts had occurred. Percentage of patients that did not accept route of treatment mentioned
Free of selective reporting	Low risk	All planned outcomes reported
Free of other bias	High risk	Little information on participants in each group as baseline

ASA I/ASA II = American Society of Anesthesiologists (ASA) physical status classification; BIS = bispectral index; DSTG = Dental SedationTeachers Group scale; ITT = intention‐to‐treat; IV = intravenous; LA = local anaesthesia; min = minute; RCT = randomised controlled trial; SD = standard deviation; SE = standard error.