The aim of this study was to determine whether  in patients diagnosed with pulpal necrosis and associated periapical radiolucency with moderate to severe preoperative pain ibuprofen or ibuprofen/acetaminophen was more effective for postoperative endodontic pain.

71 patients with a  symptomatic tooth with a pulpal diagnosis of necrosis and moderate to severe pain at the time of treatment  underwent emergency debridement of the tooth with hand and rotary instrumentation and were then randomised to receive capsules of either 600 mg ibuprofen or 600 mg ibuprofen combined with 1000 mg acetaminophen. Patients were asked to record pain, symptoms, and the number of capsules taken. Patients received escape medication (Vicodin) if the study medication did not control their pain.

They found

• There were decreases in pain levels and analgesic use over time for the ibuprofen and ibuprofen/acetaminophen groups.
• No statistically significant differences between the 2 groups
• Approximately 20% of patients in both groups required escape medication to control pain

They concluded

there was no statistically significant difference between the ibuprofen and  ibuprofen/acetaminophen group for analgesic or escape medication use.

Wells LK, Drum M,  Nusstein J, Reader A, Beck M. Efficacy of Ibuprofen and Ibuprofen/Acetaminophen on Postoperative Pain in Symptomatic Patients with a Pulpal Diagnosis of Necrosis. J of Endod. Vol 37, (12), 2011, Pages 1608-1612. Available online 29 September 2011.