Primosch 1993.

Methods	RCT Parallel design
Participants	Location: USA Children undergoing variety of dental procedures, N = 60 Setting: paediatric dental clinic Mean age (years) 7.3 (range 4.6 to 10.5)
Interventions	Group 1: 80 mg paracetamol 20 minutes preoperatively (N = 30) Group 2: placebo 20 minutes preoperatively (N = 30) All oral
Outcomes	Prevalence of pain related behaviours postoperatively
Notes	Groups further subdivided into restoration or extraction (N = 15 per subgroup)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants "randomly divided"
Allocation concealment (selection bias)	Unclear risk	Trial authors referred to allocation concealment but did not explain the method
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Participants were blinded to the therapy, but it is unclear whether assessors and operators were blinded as well
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data from included participants were complete
Selective reporting (reporting bias)	Low risk	All expected outcomes reported
Other bias	Low risk	None apparent