title: Effect of Buffered 4% Lidocaine on the Success of the Inferior Alveolar Nerve Block in Patients with Symptomatic Irreversible Pulpitis: A Prospective, Randomized, Double-blind Study.
abstract: BACKGROUND
  Medical studies have suggested that buffering local anesthetic may increase the ability to achieve anesthesia. The purpose of this study was to determine the effect of 4% buffered lidocaine on the anesthetic success of the inferior alveolar nerve (IAN) block in patients experiencing symptomatic irreversible pulpitis.
  
  
  METHODS
  One hundred emergency patients diagnosed with symptomatic irreversible pulpitis of a mandibular posterior tooth randomly received a conventional IAN block using either 2.8 mL 4% lidocaine with 1:100,000 epinephrine or 2.8 mL 4% lidocaine with 1:100,000 epinephrine buffered with sodium bicarbonate in a double-blind manner. For the buffered solution, each cartridge was buffered with 8.4% sodium bicarbonate using the OnPharma (Los Gatos, CA) system to produce a final concentration of 0.18 mEq/mL sodium bicarbonate. Fifteen minutes after administration of the IAN block, profound lip numbness was confirmed, and endodontic access was initiated. Success was defined as no or mild pain (≤54 mm on a 170-mm visual analog scale) on access or instrumentation of the root canal.
  
  
  RESULTS
  The success rate for the IAN block was 32% for the buffered group and 40% for the nonbuffered group, with no significant difference (P = .4047) between the groups. Injection pain ratings for the IAN block were not significantly (P = .9080) different between the 2 formulations.
  
  
  CONCLUSIONS
  For mandibular posterior teeth, a 4% buffered lidocaine formulation did not result in a statistically significant increase in the success rate or a decrease in injection pain of the IAN block in patients with symptomatic irreversible pulpitis.
authors.affiliation: Practice Limited to Endodontics, Oklahoma City, Oklahoma.
authors.forename: Jared
authors.initials: J
authors.lastname: Schellenberg
authors.affiliation: Division of Endodontics, The Ohio State University, Columbus, Ohio.
authors.forename: Melissa
authors.initials: M
authors.lastname: Drum
authors.affiliation: Division of Endodontics, The Ohio State University, Columbus, Ohio. Electronic address: reader.2@osu.edu.
authors.forename: Al
authors.initials: A
authors.lastname: Reader
authors.affiliation: Division of Endodontics, The Ohio State University, Columbus, Ohio.
authors.forename: John
authors.initials: J
authors.lastname: Nusstein
authors.affiliation: Division of Endodontics, The Ohio State University, Columbus, Ohio.
authors.forename: Sara
authors.initials: S
authors.lastname: Fowler
authors.affiliation: Division of Biosciences, The Ohio State University, Columbus, Ohio.
authors.forename: Mike
authors.initials: M
authors.lastname: Beck
mesh_terms: D000293:Adolescent; D000328:Adult; D000539:Alveolar Process / Q000294:innervation*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D011671:Pulpitis / Q000628:therapy*; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine
keywords: Buffered lidocaine; inferior alveolar nerve block; irreversible pulpitis; lidocaine; symptomatic irreversible pulpitis