IRCT2014040417118N1 IRCT 2015-08-13 Vice Chancellor for Research ,Tabriz University of Medical Science The Effect of Pharmapain and Dexamethasone on Reducing Pain during Root Canal Therapy of Mandibular Teeth Clinical Trial of Comparison of the Effect of Premedication with Pharmapain, Dexamethasone and Placebo on Pain Severity after Administration of Anesthesia in Inferior Molar Teeth with Irreversible Pulpitis 2014-08-23 anticipated 210 Complete https://irct.ir/trial/15821 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Supportive, Other design features: To randomize the patients, each patient was assigned a number. Numbers were randomly divided into three groups. The numbers in each group were written on paper, and each one was kept in a separate sealed opaque envelope. Each patient was asked to choose one of the envelopes and was assigned to one of the groups on the basis of the number. In this study, participants (patients) and researchers are blinded to the type of drugs.(Double - blind). 3 Irreversible Pulpitis. Intervention 1: Control2 intervention group one Capsule Dexamethasone 0.5 mg(Aburaihan Pharmaceutical Co, Iran) 30 min before injection Intervention category treatment. Intervention 2: Control3 control group one Capsule (placebo: Lactose) 30 min before injection. Intervention 3: intervention groups one Capsule pharmapain 400 mg( Pharma chemie Pharmaceutical Co , Iran) 30 min before injection.