Isik 2008a.

Methods	Parallel Funding: not stated Location: Turkey
Participants	Inclusion criteria: children requiring sedation for dental procedures Mean age (SD) in years, gender, mean weight (SD) in kg: Group 1 (n = 15), 4.87 (0.99), 7 males, 8 females, 18.87 (2.5) Group 2 (n = 15), 4.93 (1.11), 7 males, 8 females, 17.87 (3.88) Group 3 (n = 15), 4.93 (1.10), 8 males, 7 females, 18.6 (3.31) Group 4 (n = 15), 5.01 (1.03), 9 males, 6 females, 19.73 (4.77)
Interventions	Group 1: melatonin (3 mg) (60 minutes prior to treatment) Group 2: melatonin (0.5 mg/kg) (60 minutes prior to treatment) Group 3: midazolam (0.75 mg/kg) (15 minutes prior to treatment) Group 4: placebo (half group 15 minutes prior to treatment and half 60 minutes prior to treatment) All oral, administered by nurse
Outcomes	Ramsay Sedation Score
Notes	40:60 nitrous oxide/oxygen given to all Sample size calculation given
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomly assigned" ‐ method of sequence generation not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding ‐ Participant	Low risk	Study reported as double‐blind
Blinding ‐ Operator/sedationist	Low risk	Quote: "neither the researcher nor the parents were informed which drug was administered"
Blinding ‐ Outcome assessor	Low risk	Study reported as double‐blind
Incomplete outcome assessment	Low risk	All patients evaluated
Free of selective reporting	Low risk	All planned outcomes reported
Free of other bias	Low risk	No apparent differences between the groups at baseline