Table 4. Risk of bias in Nguyen et al. 2017.

Nguyen et al. 2017 15
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer-generated simple random numbers sequence with a one to one allocation ratio.
Allocation concealment (selection bias)	Low risk	Quote: Allocation occurred after induction of general anesthesia to ensure allocation concealment. The pediatric dentist, nurse, or assistant directed subjects at the time of dental surgery to the appropriate treatment group they had been assigned to by the investigator.
Blinding of participants and personnel (performance bias)	Low risk	Quote: All other contributors were blinded to generation and implementation of the treatment assignment
Blinding of clinical outcomes assessment	Low risk	Quote: A single investigator, who did not perform any pulp therapy or participate in radiographic evaluation, performed all clinical assessments.
Blinding of radiological outcomes assessment	Low risk	Quote: Two experienced pediatric dentists who did not participate in protocol development or treatment performed radiographic assessments. It is not possible to blind the assessors due to the nature of treatment received.
Incomplete outcome data (attrition bias)	Low risk	9% drop out of 172 incisors at 12 months, due to loss to follow-up (n=13) and due to trauma (n=2). 21% drop out of 172 incisors at 18 months, due to loss to follow-up or dropout (n =31), exfoliation (n = 3), and trauma (n = 3).
Reporting bias	Low risk	We revised the protocol that was registered with the ClinicalTrials.gov Protocol and Registration System (ID no. NCT02019563)