Abanto 2014.

Study characteristics
Methods	Study design: parallel‐group randomized controlled trial Sample size: 60 Country: Peru Setting: dental clinic Dates conducted: November 2013 to July 2014 Postoperative opioid used and delivery: none Pain score collection: researcher Concurrent postoperative analgesics: paracetamol or NSAID
Participants	Inclusion criteria ASA 1 Aged 18 to 45 years old Complete primary education Undergoing simple dental extraction for dental caries and asymptomatic at the time of extraction with a previous history of extraction Exclusion criteria Refused study participation Contraindication to extraction or study drugs Pregnancy or breast‐feeding Patients receiving anaesthesia, sedatives, paracetamol, NSAIDs, tricyclic antidepressants, opioids, corticosteroids, anticonvulsants, phenothiazines, alcohol or caffeine 48 hours before the extraction Intellectual disability Procedure could not be performed Exceeded two tubes of anaesthetic (> 3.6 mL) to achieve adequate anaesthesia Pain more than 70 mm (on a 100 mm VAS) pre‐extraction Procedures exceeded 20 minutes Participants who did not fill in the measuring instrument correctly Participants who did not comply with the instructions, abandoned the study, did not attend postoperative control or those who presented with any of the following post‐extraction complications: haemorrhage, infection, alveolitis, soft tissue lesions, bone or adjacent parts
Interventions	Group Prophylactic (30 participants): naproxen sodium 550 mg PO 30 minutes before the procedure, then every 12 hours for 4 doses Group Continuous (30 participants): naproxen sodium 550 mg PO 20 minutes after the procedure, then every 12 hours for 4 doses
Outcomes	Postoperative pain (0‐100 mm VAS at 1, 8 and 24 hours) Adverse effects (no details given)
Notes	Funding: not reported Declarations of interest: not reported Authors contacted: no Other: article in Spanish. Unpublished thesis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Unclear details. Quote: "Patients were randomly assigned".
Allocation concealment (selection bias)	Unclear risk	No mention
Blinding of participants and personnel (performance bias) All outcomes	High risk	No mention of double‐dummy placebo. Quote: "Naproxen sodium 550 mg was administered orally 30 minutes before the procedure, then every 12 hours until the 4 doses".
Blinding of outcome assessment (detection bias) All outcomes	High risk	Likely unblinded from above information
Incomplete outcome data (attrition bias) All outcomes	Low risk	Three excluded for alveolitis unlikely to bias results as this would cause confounding from increased pain. Quote: "Three people were eliminated by alveolitis".
Selective reporting (reporting bias)	Unclear risk	No registration or protocol. Unpublished thesis
Other bias	Unclear risk	No detailed information on baseline characteristics