Supplementary Routes of Dental Anesthesia

Supplementary Routes of Dental Anesthesia by Dental Resource Center on 4/8/2006
Four Supplementary Routes of Dental Anesthesia The unfortunate reality with conventional methods of local anesthesia in dentistry is that they do not always work. Rates of success for the commonly practiced inferior alveolar nerve block (IANB) have averaged 69% to 85%,(1) but even lower success rates have been reported (e.g., 43%).(2) The search for improved anesthetics and better routes of administration continues. In this blog, four supplementary routes of dental anesthesia are reviewed.Periodontal Ligament Injection As a supplement to submucosal anesthesia, periodontal ligament injection uses the periodontal ligament space to deliver anesthesia intraosseously.(1,6) The advantages are a rapid onset of anesthesia with no collateral effects, the ability to operate bilaterally in the mandible, less volume of anesthetic compared to that used with IANB, and the possibility of anesthetizing an abscessed tooth. On the other hand, post-operative pain may be greater, a decrease in pulpal blood flow may result, pressure is required to inject the anesthetic, multiple injections are needed for multirooted teeth, and access to posterior areas is limited.(1,6) Intraosseous InjectionsIntraosseous injections anesthetize a single tooth by injecting local anesthesia into cancellous bone.(1,6) The epithelium, connective tissue, periosteum, and cortical plate of bone are perforated to introduce anesthesia into the tooth. Advantages include immediate onset of local anesthesia with no collateral anesthetic effects, and the ability to operate bilaterally in the mandible. Disadvantages are that the anesthetic effect is short-term, the possibility of intravascular injection and of toxicity exist, palpitations may occur when the anesthetic is co-administered with epinephrine, access to posterior areas is limited, and it is technically more difficult than infiltration anesthesia. However, in cases where a conventional anesthetic falls short, supplementary intraosseous injection may be beneficial. Without supplementary intraosseous anesthesia, the success rate from six studies averaged 69%; this increased to 97% when intraosseous injection was used.(2)Lingual InfiltrationLingual infiltration of the mandible is a newer technique that, in combination with buccal injection, may provide profound local anesthesia.1 Lingual infiltration offers a thin cortical plate and lingual foramina, thus facilitating absorption and flow of the anesthetic through the bone; it is generally well-accepted by patients. However, ballooning of tissue may occur, and care must be taken to avoid the submandibular salivary gland during injection.(1) Intrapulpal Injection Lastly, intrapulpal injection is generally used after failure of a previously administered anesthetic. It acts quickly as the anesthetic solution is deposited directly into the pulp chamber. However, because it requires pulpal exposure and may be painful, its use is limited.(6) Apart from alternate routes of delivery of commonly used pharmacologic anesthetics, researchers are exploring nonpharmacologic ways to improve anesthesia in dentistry. For example, a pilot study has shown that acupuncture can reduce the onset time of anesthesia using a regional inferior dental block with prilocaine hydrochloride.7 In another study, it was found that acupuncture can be a useful adjunct to conventional anesthesia in maxillofacial surgery.(8) There are a number of viable ways to enhance the success of local anesthetics used in dentistry. A dental procedure should not have to be abandoned due to the inability to achieve adequate anesthesia. References1. Hawkins JM, Moore PA. Local anesthesia: Advances in agents and techniques. Dent Clin North Am 2002;46(4):719-732, ix.2. Wong JK. Adjuncts to local anesthesia: Separating fact from fiction. J Can Dent Assoc 2001;67(7):391-397.3. Yagiela JA. Recent developments in local anesthesia and oral sedation. Compend Cont Educ Dent 2004;25(9):697-706.4. Berlin J, Nusstein J, Reader A, Beck M, Weaver J. Efficacy of articaine and lidocaine in a primary intraligamentary injection administered with a computer-controlled local anesthetic delivery system. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;99(3):361-366.5. Jeffcoat MK, Geurs NC, Magnusson I, MacNeill SR, Mickels N, Roberts F, et al. Intrapocket anesthesia for scaling and root planing: Results of a double-blind multicenter trial using lidocaine prilocaine dental gel. J Periodontol 2001;72(7):895-900.6. Meechan JG. Supplementary routes to local anaesthesia. Int Endod J 2002;35(11):885-896.7. Rosted P, Bundgaard M. Can acupuncture reduce the induction time of a local anaesthetic?—A pilot study. Acupunct Med 2003;21(3):92-99.8. Pohodenko-Chudakova IO. Acupuncture analgesia and its application in craniomaxillofacial surgical procedures. J Craniomaxillofac Surg 2005;33(2):118-122. Content from this blog comes from the Oral Care Report copyrighted to Colgate-Palmolive Company.