Buffering of local anesthetics (alkalinization) has been suggested in achieving pain control. The purpose of this prospective, randomized, double-blind study was to evaluate the effect of adding 0.6 mL 8.4% sodium bicarbonate to 3.0 mL 2% lidocaine with 1: 80,000 epinephrine on the success rate of IAN block for endodontic treatment of mandibular molars with symptomatic irreversible pulpitis.

Some studies have been shown buffering of local anesthetics reduce pain of injection, hasten the onset of anesthesia, and improved success rate of anesthesia. Others reported buffering of local anesthetics cannot reduce pain of injection, hasten the onset of anesthesia, and improve success rate of anesthesia. There are no studies evaluating a sodium bicarbonate-buffered lidocaine formulation for IAN block for teeth with irreversible pulpitis.

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