Al‐Bahlani 2001.

Methods	Study design: 2‐arm parallel randomised trial Conducted in: UK Number of centres: 1 Setting: dental hospital Recruitment period: unclear Funding source: not reported
Participants	Inclusion criteria: unclear; medically fit and well Exclusion criteria: not reported Number of participants randomised/evaluated: total = 100 (group 1 = 50, group 2 = 50) Age range = 3 to 5 years
Interventions	Group 1: IFL, 0.5 ml 2% lignocaine with 1:80,000 adrenaline infiltration per quadrant Group 2: NLA
Outcomes	TPPPS and assessment of bleeding through total blood loss per root Measured at 1 minute, 5 to 6 minutes, and 11 minutes postoperatively
Notes	Co‐interventions: none reported Declarations of interest: none reported There was no sample size calculation The observation period for the TPPPS was reduced from the validated period of 30 minutes to 11 minutes: "no greater discrimination between groups could be determined after this period of observation"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomly allocated" Comment: The paper did not describe the method of sequence generation
Allocation concealment (selection bias)	Unclear risk	The paper did not describe the method of allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Explanation was made to the child of the sensations to be expected postoperatively either with or without local analgesia" Comment: The study did not blind participants. It was unclear whether personnel were blinded as the comparator was no treatment
Blinding of outcome assessment (detection bias) All outcomes	High risk	Outcome assessment was blinded; however, the study did not blind participants, and this may well have influenced how they behaved postoperatively
Incomplete outcome data (attrition bias) All outcomes	Low risk	The outcome evaluation included all participants
Selective reporting (reporting bias)	Low risk	The study reported all outcomes, but it was not clear whether the single summary distress scores presented were averaged over all 3 periods of measurement or reported for a single (unspecified) time point
Other bias	High risk	The authors reduced the observation period for TPPPS from the validated period of 30 minutes to 11 minutes as "no greater discrimination between groups could be determined after this period of observation"