The efficacy of pre-operative oral aceclofenac and intra-ligamentary mepivacaine on the success of failed inferior alveolar nerve block in patients with symptomatic irreversible pulpitis: a prospective, randomised, double-blinded clinical trial.

Objective: This study aimed to compare the effects of oral pre-operative aceclofenac and supplemental intra-ligamentary mepivacaine and articaine injection on the anaesthetic efficacy of failed inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis in mandibular molars. Materials and Methods: A total of 126 patients who fulfilled the inclusion criteria were selected for the study intervention. The study design was a prospective, randomised, double-blinded clinical trial. Pre-operative medication was administered 15 minutes before the patients received the standard IANB. Subsequently, the endodontic therapy was started. Pain felt at any time during the procedure was recorded on a 170 mm Heft-Parker visual analogue scale (VAS), and a supplemental intra-ligamentary injection was administered. Based on the pre-operative medication and the intra-ligamentary injection received, the patients were categorized into the following four groups: two groups received 4% articaine with 1:100,000 epinephrine as an intra-ligamentary injection with or without aceclofenac as the pre-operative medication (Group 1 and Group 2, respectively), and two other groups received 3% plain mepivacaine with or without aceclofenac (Group 3 and Group 4, respectively). The VAS scores were determined pre-operatively, following access preparation and/or instrumentation within the dentin, the pulpal space, and the instrumentation of canals. Data were analyzed using Pearson's chi-square test and independent Results: Concerning the supplemental intra-ligamentary injection, 4% articaine with 1:100,000 epinephrine showed a higher success rate than 3% plain mepivacaine, irrespective of the pre-operative medication used, and the difference was statistically significant ( Conclusions: In patients with symptomatic irreversible pulpitis of mandibular molars, an intraligamentary injection of 4% articaine combined with 1:100,000 epinephrine can significantly aid in achieving anesthesia in situations where primary IANB is unsuccessful. Clinical Relevance: Mandibular molars with symptomatic irreversible pulpitis are associated with a high anaesthetic failure rate of a single primary IANB injection during endodontic treatment. Adding an oral pre-operative aceclofenac medication and a supplemental intra-ligamentary injection, augments the anaesthetic efficacy in such cases.