The purpose of this prospective, randomized, double blind study was to evaluate the effect of a buccal infiltration of sodium bicarbonate on the anesthetic success of the inferior alveolar nerve block (IANB) in patients with mandibular first molar experiencing symptomatic

Several studies have been done by adding Sodium Bicarbonate to local anesthesia in dentistry based on the theory that the amount of local anesthetic in the free-base un-ionized form will decrease to provide greater lipid penetration of the nerve and this could be cause of the failure of local anesthesia injected into the inflamed tissue with low PH and conflicting results were obtained. But, there are no study that evaluate effect of increasing PH in periradicular tissue on hindrance of resistance channels with supplementary infiltration injection of Sodium Bicarbonate

Inclusion Criteria:

• vital mandibular molar tooth
• diagnosis of symptomatic irreversible pulpitis

Exclusion Criteria:

• younger than 18 years old
• history of significant medical conditions
• allergies to local anesthetics or sulfites
• pregnancy
• taking any medications that might influence anesthetic assessment
• active sites of pathosis in area of injection
• inability to give informed consent