Profound anesthesia is needed if the tooth is to be removed without pain for the patient therefore It is essential that the surgeon remember the precise innervations of all teeth and surrounding soft tissue and the kinds of injection necessary to anesthetize those nerves totally. Table 7-1 summarizes the sensory innervation of the teeth and surrounding tissue.It Is important to remember that, in areas of nerve transition, some overlap exists. For example, in the region of the mandibular second premolar, the buccal soft tissues are innervated primarily by the mental branch of the Inferior alveolar nerve but also by terminal branches of the long buccal nerve.Therefore it may be necessary to supplement the Inferior alveolar nerve block with a long buccal nerve block to achieve adequate anesthesia of the buccal soft tissue when extracting this particular tooth.
When anesthizing a maxillary tooth for extraction,the surgeon should anesthetize the adjacent teeth as well During the extraction process the adjacent teeth are usually subjected to certain amounts of pressure, which may be sufficient to cause the patient pain. This is also true for mandibular extractions, but the mandibular block anesthetic usually produces sufficient anesthesia.
Profound local anesthesia results In the loss of all pain, temperature, and touch sensations, but it does not anesthetize the proprioceptive fibers of the Involved nerves.Thus the patient feels a sensation of pressure, especially when the force is intense. The surgeon must therefore remember that the patient will need to distinguish between sharp pain and the dull, albeit Intense, feeling of pressure.
In spite of profound soft tissue anesthesia and apparent pulpal anesthesia, the patient may continue to have sharp pain as the tooth Is luxated. This is especially likely when the teeth have a pulpltls or the surrounding soft and hard tissues are inflamed or infected. A technique that should be employed In these situations is the periodontal ligament injection. When this Injection Is delivered properly and the local anesthetic solution Injected under pressure, Immediate profound local anesthesia occurs in almost all situations. The anesthesia Is relatively short-lived, so the surgical procedure should be one that can be accomplished within 15 or 20 minutes Intraosseous injections may be used where standard and periodontal ligament injections have failed, The Stabident System is useful for the intraosseous injection.
It Is important to keep in mind the pharmacology of the various local anesthetic solutions that are used so that they can be employed properly. Table 7-2 summarizes the commonly used local anesthetics and the amount of time they can be expected to provide profound anesthesia. The dentist must remember that pulpal anesthesia of maxillary teeth after local infiltration lasts a much shorter time than does pulpal anesthesia of mandibular teeth after block anesthesia. In addition pulpal anesthesia disappears 60 to 90 minutes before soft tissue anesthesia does. Therefore it is quite possible that a patient may still have lip anesthesia after having lost pulpal anesthesia and may be experiencing pain.
Only a certain amount of local anesthetic can be safely used in a given patient. To provide profound anesthesia for multiple tooth extractions It may be necessary to inject multiple cart ridges of local anesthetic, Thus It is important to know how many cartridges of a given local , anesthetic solution can be administered safely. Table 7-3 summarizes (in tw0 different ways) the maximal amounts of local anesthetic that can be used. first. each local anesthetic has a recommended maximal dose based on milligrams per kilogram, The second column in Table 7-3 indicates the number of cartridges that can’safely he used on a healthy 15~ pound (70 kg) adult. It Is rarely necessary to exceed this dose, even in patients larger than 154 pounds. Patients who are smaller, especially children, should be given proportionally less local anesthetic. The’ most likely victim of overdose Is the small child to whom 3% meplvacalne (Carbocalne) Is administered. For a patient who weighs 44 pounds (20 kg), the recommended maximal amount of rneplvacalne Is 100 mg. If the child is given two cartridges of 1.8 ml each, the dose totals 108 mg. Therefore a third cartridge of 3% meplvacaine should be avoided. It Is wise to remember that the smallest amount of local anesthtic solution sufficient to provide profound anesthesia Is the proper amount.
Although it Is self-evident that local anesthesia Is necessary for Intraoperative pain control, the surgeon should also acknowledge Its role In postoperative pain control.For routine extractions where mild-to-moderate analgesics only will be necessary usually no additional local anesthetic Is necessary. After procedures that have been more traumatic (e.g. the removal of Impacted teeth) and where stronger analgesics are likely to be necessary many surgeons use a long-lasting local anesthetic (e.g etidocain), Instead of or In addition to their usual local anesthetic. By doing this the clinician provides the patient with 4 to 6 hours of local anesthetic with no pain.This method also allows adequate time for the patient to take the required analgesics and for the analgesics to take effect before the discomfort begins.