title: Does the volume of supplemental intraligamentary injections affect the anaesthetic success rate after a failed primary inferior alveolar nerve block? A randomized-double blind clinical trial.
abstract: OBJECTIVE
  To investigate the efficacy of 0.2 mL vs. 0.6 mL of 2% lidocaine when given as a supplementary intraligamentary injection after a failed inferior alveolar nerve block (IANB).
  
  
  METHODS
  Ninety-seven adult patients with symptomatic irreversible pulpits received an IANB and root canal treatment was initiated. Pain during treatment was recorded using a visual analogue scale (Heft-Parker VAS). Patients with unsuccessful anaesthesia (n = 78) randomly received intraligamentary injection of either 0.2 mL or 0.6 mL of 2% lidocaine with 1 : 80 000 epinephrine. Root canal treatment was reinitiated. Success after primary injection or supplementary injection was defined as no or mild pain (HP VAS score ≤54 mm) during access preparation and root canal instrumentation. Heart rate was monitored using a finger pulse oximeter. The anaesthetic success rates were analysed with Pearson chi-square test at 5% significance levels. The heart rate changes were analysed using t-tests.
  
  
  RESULTS
  The intraligamentary injections with 0.2 mL solution gave an anaesthetic success rate of 64%, whilst the 0.6 mL was successful in 84% of cases with failed primary IANB. (χ2= 4.3, P = 0.03). There was no significant effect of the volume of intraligamentary injection on the change in heart rate.
  
  
  CONCLUSIONS
  Increasing the volume of intraligamentary injection improved the success rates after a failed primary anaesthetic injection.
authors.affiliation: Department of Conservative Dentistry & Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India.
authors.forename: V
authors.identifier: http://orcid.org/0000-0002-9792-4554
authors.initials: V
authors.lastname: Aggarwal
authors.affiliation: Department of Conservative Dentistry & Endodontics, SGT Dental College, Gurgaon, Haryana, India.
authors.forename: M
authors.initials: M
authors.lastname: Singla
authors.affiliation: Department of Conservative Dentistry & Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India.
authors.forename: S
authors.initials: S
authors.lastname: Miglani
authors.affiliation: Department of Conservative Dentistry & Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India.
authors.forename: S
authors.initials: S
authors.lastname: Kohli
authors.affiliation: Department of Conservative Dentistry & Endodontics, SGT Dental College, Gurgaon, Haryana, India.
authors.forename: V
authors.initials: V
authors.lastname: Sharma
authors.affiliation: Department of Conservative Dentistry & Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India.
authors.forename: S S
authors.initials: SS
authors.lastname: Bhasin
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007267:Injections; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D009407:Nerve Block / Q000009:adverse effects*; D011446:Prospective Studies; D011671:Pulpitis / Q000628:therapy*; D012390:Root Canal Therapy; D017211:Treatment Failure; D064232:Visual Analog Scale; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine
keywords: 2% lidocaine; inferior alveolar nerve block; intraligamentary injection; irreversible pulpitis; mandibular molars