Oginni 2004.

Methods	Study design: randomised parallel group, clinical trial. Conducted in Nigeria. Number of Centres: 1. Restorative Dentistry Department, Obafemi Awolowo University Teaching Hospitals Complex, Ile‐Ife, Nigeria. Recruitment period: 12 months. Funding source: not reported.
Participants	255 patients (sex, range or mean age not reported) were enrolled in the study for a total of 283 teeth (1.11 teeth per patient); 227 teeth were included in the final analysis about pain and flare‐up. For patients with more than 1 tooth requiring treatment, the treatment of each tooth was separated by a period of at least 4 weeks. Inclusion criteria: all patients referred to the Department of Restorative Dentistry for root canal therapy. Exclusion criteria: patients that did not turn up after the first appointment (incomplete treatment). Diagnostic criteria for pulpal or periapical disease: the pulp vitality was determined by an electric pulp tester in combination with the presence of pulpal haemorrhage. Group 1: randomised 129 107 teeth evaluated (1st postobturation day); 104 (7th postobturation day); 102 (30th postobturation day). Group 2: randomised 154, 136 teeth evaluated (1st postobturation day); 123 (7th postobturation day); 120 (30th postobturation day).
Interventions	Group 1: single visit. Group 2: multiple visits (medication and number of visits in the multiple‐visit treatment not reported). Rubber dam isolation, use of magnification loupes, canal shaping, irrigation, working length not reported. The root canals were obturated with multiple gutta‐percha cones and a zinc oxide‐eugenol based sealer, using the lateral condensation technique.
Outcomes	Pain Incidence and degree of pain at the 1st, 7th and 30th days postobturation. Pain was recorded as none, slight or moderate/severe. We considered only 2 categories: pain (slight and moderate\severe), and no pain. Flare‐up Defined as either patient reporting pain not controlled with over‐the‐counter medication or increasing swelling or both (see Table 3).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: insufficient information to permit judgement.
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information to permit judgement.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: not applicable, radiographic assessment was not among outcomes.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	56 teeth (25 from single‐visit group, 31 from multiple‐visit group) were excluded from the study due to non availability of participants at postobturation recall visits. 85.86% of patients who entered the study were included in the final analysis about pain and flare‐up in the 1st day; 80.21% of patients who entered the study were included in the final analysis of pain and flare‐up on the 7th day; 78.4% of patients who entered the study were included in the final analysis at 30th day.
Selective reporting (reporting bias)	Low risk	Planned outcomes reported.
Other bias	High risk	It is not explicitly stated that participants with more that one tooth needing treatment were randomised the same number of times.