Fei 1991.

Methods	RCT, parallel‐arm Teeth randomly assigned Conducted in the Pediatric Dental Clinic at the University of Southern California School of Dentistry. Operators not mentioned
Participants	62 children, 83 teeth, mean age 6.7 years, age range 3.2 to 10.1 years
Interventions	Group 1:Pulpotomy (formocresol); n = not stated (27 teeth analysed) (1 visit) Rubber dam Caries removal prior to pulpal access Pulp access with high‐speed bur Pulpotomy amputation with excavator or slow‐speed bur For haemostasis, dry cotton pellet No irrigation Cotton wool pellet soaked with FC placed on pulp stumps for 5 minutes after pulpotomy, followed by ZOE and IRM before being restored with stainless‐steel crowns Group 2:Pulpotomy (ferric sulphate); n = not stated (29 teeth analysed) (1 visit) Rubber dam Caries removal prior to pulpal access Pulp access with high‐speed bur Pulpotomy amputation with excavator or slow‐speed bur For haemostasis, dry cotton pellet No irrigation 15.5% FS solution applied after pulpotomy, followed by ZOE and IRM before being restored with stainless‐steel crowns
Outcomes	Clinical success (no symptoms of pain, tenderness to percussion, swelling, fistulation or pathological tooth mobility), radiographic success (normal periodontal ligament, absence of pathological internal root resorption, external root resorption, no intraradicular or no periapical radiolucency), signs of failure (symptoms of pain, tenderness to percussion, swelling, fistulation, pathological tooth mobility, abnormal periodontal ligament, pathological internal root resorption, external root resorption, intraradicular or periapical radiolucency), internal root resorption, pulp canal obliteration: evaluation at 3, 6 and 12 months (at tooth level)
Notes	56 teeth from 48 children were available for evaluation after 12 months (Group 1: 27; Group 2: 29) Source of funding: not reported, although FS material was provided by a manufacturer Quote: "The ferric sulphate tested in this study was provided by the Ultradent Company"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers table
Allocation concealment (selection bias)	Unclear risk	Insufficient information to make a clear judgement
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information to make a clear judgement
Blinding of clinical outcomes assessment	Low risk	Quote: "Clinical evaluations of the teeth were conducted by two independent examiners who had no knowledge of the group to which the particular tooth was assigned"
Blinding of radiological outcomes assessment	Low risk	Quote: "Radiological evaluations of the teeth were conducted by two independent examiners who had no knowledge of the group to which the particular tooth was assigned"
Incomplete outcome data (attrition bias) All outcomes	High risk	Number of randomised teeth unknown
Selective reporting (reporting bias)	Unclear risk	Insufficient information to make a clear judgement