Endodontic anaesthesia in the hot tooth: integrating mechanisms, clinical evidence, and practice-based clinical insights

The management of pain is an important aspect in endodontic therapy. Among all the clinical situations, the attempt to gain complete endodontic anaesthesia is the most challenging, particularly when the patient is diagnosed with symptomatic irreversible pulpitis, known in clinical practice as the “hot tooth”. These clinical situations are the most unpredictable and most challenging for the clinician. The clinical failure of the inferior alveolar nerve block (INAB) in these situations is due to an intricate interplay of anatomy, tissue inflammation, neural inflammation, and patient psychology. Although multiple strategies have been proposed to improve anaesthesia in the hot tooth, there remains a lack of integrated, clinically applicable decision-making frameworks to guide anaesthetic management. The primary objective of this review is to integrate findings of various clinical trials, pathophysiological mechanisms, and clinical approaches to solve the issue of achieving anaesthesia in inflamed mandibular molars. This review focuses on five parameters: the volume of anaesthetic drug, the rate of injection, the head position of the patient, preoperative pharmacological interventions, and the formulation of the drug, which are all researched in several clinical trials. This review also attempts to discuss the supplemental and rescue anaesthesia. The last part of this review presents practical clinical solutions to assist the clinician in difficult clinical scenarios.