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.

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, χ = 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.