IRCT201409142541N4 IRCT 2016-05-24 Vice chancellor for research, Isfahan University of Medical Sciences Effect of sodium bicarbonate on success of inferior alveolar anesthesia IANB=inferior alveolar nerve block Effect of supplementary infiltration injection of Sodium Bicarbonate on success rate of IANB of mandibular first molars with irreversible pulpitis: A Randomized, Clinical, Double-blind Study 2016-02-20 anticipated 100 Complete https://irct.ir/trial/2282 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Single, Purpose: Treatment, Other design features: Patients and physician were unaware that liquid in infiltration injection were drug or placebo therefore the study considered as a double-blind study. 2 irriversible pulpitis. Intervention 1: infiltration injection involved 0.7 ml of distilled water and 0.3 ml of 2% lidocaine with 1.80000 epinephrine. Intervention 2: infiltration injection involved 0.7 ml of sodium bicarobonate and 0.3 ml of 2% lidocaine with 1.80000 epinephrine.