Clinical Considerations of Intrapulpal Anesthesia in Pediatric Dentistry

During endodontic treatment, effective anesthesia of any vital pulp tissue present in the pulp chamber or root canals is important for patient's cooperation and to maintain the comfort level. This is particularly true in cases of pediatric patients, where ineffective analgesia might result in a traumatic experience for the kids leading to increased apprehensiveness, reduced pain threshold, inadequate cooperation, and also creates an embarrassing situation for the dentists. The most commonly used local anesthetic solution in pediatric endodontics is 2% lidocaine hydrochloride with adrenaline (1:100,000) because of its improved efficacy at low concentrations and decreased allergenic characteristics.[1] The intrapulpal injection technique (IPI) is one of the commonly employed supplemental anesthetic technique adjuvant to conventional maxillary infiltration anesthesia or mandibular inferior alveolar block in situations, where patients encounter severe pain or discomfort during pulp extirpation, especially in acutely inflamed molars.[2] Although various supplemental techniques such as intraligamentary or intraosseous techniques are available, it is wise to anticipate that in spite of apparently profound anesthesia, an IPI may be required to obtain total analgesia.[3] In general, the deposition of local anesthetic solution directly into the pulp chamber provides an effective anesthesia for extirpation, instrumentation, and debridement of pulpal tissues. The most significant factor contributing to the success of IPI is that its administration must be done under pressure. Birchfield and Rosenberg suggested that the anesthetic effect of the intrapulpal technique is mainly due to the back-pressure of the solution, independent of the type of solution injected.[4] However, when the exposure site is too large for a snug needle fit, the exposed pulp is flooded with a small amount of local anesthetic solution for a minute, premature to advancing the needle as far apically as possible into the pulp chamber and injecting under pressure.[5] Various suggested methods that aid in pressure build up in such cases include, obliteration of a large pulpal opening with either gutta-percha or a cotton pellet.[5] Nevertheless, the precise mechanism by which pressure can induce anesthesia is incompletely understood. Monheim has suggested that prolonged pressure may lead to degeneration of nerve fibers in many instances leading to profound anesthesia for long endodontic treatment procedures, as in cases of pediatric patients.[6] Following access cavity preparation and deroofing of