Intraligamentary anaesthesic injection for tooth numbing

July 31, 2021

  

Dental treatments are often deemed as painful procedures. But with the advances in anesthetic medications, these procedures can be carried out with ease such that it is comfortable for both the patient and the dentist. Patients usually are administered the anesthesia by employing two techniques: the infiltration anesthesia (for any tooth) and the inferior alveolar nerve block (IANB) (for lower teeth). While the former anesthetizes a single tooth and its surrounding structures, the latter anesthetizes an entire area of the lower jaw.

Both infiltration anesthesia and IANB provide the needed level of anesthesia in most cases. However, at times the anesthesia might not show its effect if the tooth is severely infected, if the insertion of the needle is false or if the amount of anesthesia deposited is not adequate. The dental pulp, that houses the tooth's blood vessels and nerves is located at the core of the tooth. It is this pulpal anesthesia that dentists aim to achieve after their respective modes of anesthetic techniques. In cases when the anesthesia is not effective, supplemental techniques can be used. One of these adjunctive methods is the intraligamentary technique.

The tooth is connected to its socket through the help of a complex of tissue structure called the periodontium. The periodontium has four parts - gingiva (gums), cementum (covering of the roots), alveolar bone (bony structure surrounding the tooth) and periodontal ligament (that connects the tooth to the underlying bone). It is this ligament wherein the anesthesia is deposited while giving an intraligamentary injection. The deposition of the anesthesia is done through a thin needle of 27 or 30 mm gauge. The syringe is placed in the area between the tooth and the gingiva attached to it. Once deposited, the anesthesia traverses the bony areas and diffuses into the surrounding tissues. It is through this diffusion that the anesthesia reaches the pulpal nerves an numbs them.

During administration, the dentist is likely to feel a back pressure during administration. This is because of the small area of deposition with respect to the size of the needle. Nearly 0.2 to 1ml of the solution is deposited. After administration of the anesthesia, the numbing effect begins after nearly 40 seconds. The tooth remains anesthetized for approximately 30 minutes which is sufficient to carry out the needed treatment. The intraligamentary technique is advantageous because of the fact that a longer duration of anesthesia is achieved through minimal deposition of the anesthetic solution. Moreover, unlike the IANB technique that numbs the lips and cheeks too, the intraligamentary method only numbs the area of the tooth of concern. In patients with bleeding disorders, this anesthetic technique can be useful as only minimal bleeding occurs after the syringe is withdrawn.

The intraligamentary technique cannot be used in patients with a cardiac disease and it increases the chances of bacterial contamination in the blood flow. Moreover, the high pressure required to deposit the anesthesia can damage the tissues. In young children, the erupting permanent tooth's path can also be defected as a result of the adverse effects of high pressure. The use of proper armamentarium is of paramount importance while giving an intraligamentary injection. Hence, recent advances like computer-delivered anesthesia systems or manual syringes like hand-grasp triggers can be used for proper intraligamentary injections.

The intraligamentary injection is most often used for teeth of lower arch compared to upper teeth. The success rate of tooth numbing is better during tooth extractions compared to root canal treatments. Patients have reported more amount of pain after intraligamentary injections compared to other injection techniques because of the forceful administration of the anesthetic agent due to high pressure. After the treatment, if the patient is given an IANB, he or she is advised not to bite upon their cheeks or eat or drink for a certain time period. These instructions do no apply for an intraligamentary injection and the patient can continue with their routine activities. Furthermore, there is no risk of injury to any nerves or vessels during an intraligamentary injection as compared to IANB.

The intraligamentary injection is a supplemental or adjunctive technique that should be opted for with safety in dental procedures. This technique is minimally invasive, which makes it even more preferred for both the patient and the dentist.

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