Tackling Local Anesthetic Failure in Endodontics

Achieving anesthesia in a hot tooth or tooth with inflamed pulp is challenging, especially during endodontic treatment. In the presence of symptomatic irreversible pulpitis, mainly in mandibular teeth, pose even more challenge to attain profound anesthesia. Tetradoxin resistant channel is a class of sodium channel that is found to be increased in such condition and is found to resist local anesthesia. The pH also determines the success of local anesthesia. In inflammatory conditions, the surrounding area\'s pH, which eventually decreases the amount of base form of local anesthetic penetration into the nerve membrane, thereby causing anesthetic failure. In such conditions, the excitability threshold is reduced, leading to failure in achieving anesthesia. This chapter highlights and discusses the cause of anesthetic failure and its management in obtaining profound anesthesia during endodontic treatment.

STUDY OF PRESENCE OF ACCESSORY INFRAORBITAL FORAMEN (AIOF) IN DRY HUMAN SKULLS OF NORTH INDIAN POPULATION

Introduction -IOF is a constant feature on the anterior surface of body of maxilla below the orbital margin.Infraorbital nerve (ION) & vessels pass through it .IOF assumes great importance in the field of Maxillo- facial surgery & dentistry as ION isanaesthetised during these procedures. Aims & Objective: Presence of accessory IOF affects the process of nerve block as a branch of the nerve, may pass through it. Hence a study was conducted to determine the presence of accessory IOF. Method: The study was conducted in Department of Anatomy, G.S.V.M. Medical College, Kanpur.300 macerated dry adult human skulls of north Indian population belonging to both sexes were selected. Numbers of accessory IOF was determined by direct inspection. Result:The present study found 10.7% of skulls have accessory IOF. Conclusion: Thus knowledge of presence of Accessory IOF plays an important role in nerve block which, if ignored, would result in anesthetic failure & injury to nerve.

Sensitivity, Specificity, Predictive Values, and Accuracy of Three Diagnostic Tests to Predict Inferior Alveolar Nerve Blockade Failure in Symptomatic Irreversible Pulpitis

Introduction.The inferior alveolar nerve block (IANB) is the most common anesthetic technique used on mandibular teeth during root canal treatment. Its success in the presence of preoperative inflammation is still controversial. The aim of this study was to evaluate the sensitivity, specificity, predictive values, and accuracy of three diagnostic tests used to predict IANB failure in symptomatic irreversible pulpitis (SIP).Methodology.A cross-sectional study was carried out on the mandibular molars of 53 patients with SIP. All patients received a single cartridge of mepivacaine 2% with 1 : 100000 epinephrine using the IANB technique. Three diagnostic clinical tests were performed to detect anesthetic failure. Anesthetic failure was defined as a positive painful response to any of the three tests. Sensitivity, specificity, predictive values, accuracy, and ROC curves were calculated and compared and significant differences were analyzed.Results.IANB failure was determined in 71.7% of the patients. The sensitivity scores for the three tests (lip numbness, the cold stimuli test, and responsiveness during endodontic access) were 0.03, 0.35, and 0.55, respectively, and the specificity score was determined as 1 for all of the tests. Clinically, none of the evaluated tests demonstrated a high enough accuracy (0.30, 0.53, and 0.68 for lip numbness, the cold stimuli test, and responsiveness during endodontic access, resp.). A comparison of the areas under the curve in the ROC analyses showed statistically significant differences between the three tests (p<0.05).Conclusion.None of the analyzed tests demonstrated a high enough accuracy to be considered a reliable diagnostic tool for the prediction of anesthetic failure.