Preoperative Intraligamentary Injection of Dexamethasone Can Improve the Anesthetic Success Rate of 2% Lidocaine during the Endodontic Management of Mandibular Molars with Symptomatic Irreversible Pulpitis

Abstract

Introduction: The aim of this randomized, double-blind clinical trial was to evaluate the effect of preoperative administration of intraligamentary injections of diclofenac sodium and dexamethasone on the anesthetic efficacy of 2% lidocaine given as an inferior alveolar nerve block in the endodontic management of symptomatic irreversible pulpitis.

Methods: One hundred seventeen patients randomly received 1 of the 3 intraligamentary injections before the endodontic treatment: 0.9% normal saline, 25 mg/mL diclofenac sodium, or 4 mg/mL dexamethasone. After 30 minutes, patients received an inferior alveolar nerve block with 2% lidocaine and 1:80,000 epinephrine. The teeth were tested with electric pulp testing after 10 minutes. In case of a positive response, the anesthesia was considered as "failed." If the electric test response was negative, a rubber dam was applied, and endodontic treatment was started. Any pain during the treatment was recorded. The anesthesia was considered successful if the patients experienced no pain or faint/weak/mild pain during root canal access preparation and instrumentation (Heft-Parker visual analog scale score <55 mm). The effect of intraligamentary injections on maximum heart rates was also recorded. The anesthetic success rates were analyzed with the Pearson chi-square test at 5% significance.

Results: The control, diclofenac sodium, and dexamethasone groups had anesthetic success rates of 32%, 37%, and 73%, respectively. Dexamethasone was significantly more successful than the control and diclofenac sodium groups (P < .001, χ²₂ = 14.7). There were no differences between the control and diclofenac groups (P > .05). All the solutions did not significantly affect heart rates.

Conclusions: The administration of an intraligamentary injection of dexamethasone before endodontic intervention of mandibular molars with symptomatic irreversible pulpitis increases the success rates of an inferior alveolar nerve block with 2% lidocaine.

Keywords: Dexamethasone; diclofenac sodium; irreversible pulpitis; lidocaine; mandibular anesthesia.