ANESTHESIA
THE SUBSTANCE
In dentistry, substances that have a local anesthetic effect are used. It is a family of molecules that have common chemical roots and are well packaged in single-dose vials, with a possible addition of a small percentage of adrenaline.
All these substances inhibit neural transmission of pain from the peripheral nerves to the receptive areas of the brain, acting as a chemical insulator against the neural signal in the injected area.
Adrenaline is used to enhance the effect of the anesthetic, but it may also be absent.
Carbocaine, Xylocaine, Articaine are some of the products that are used.
THE SYRINGE
The most used type of syringe is the one called "for vials" and is simply a small steel structure that is sterilized for each patient, in which it is possible to insert the anesthetic vial and a needle, both disposable.
There are other particular types of syringe, such as the one for practicing the so-called intraligamentous anesthesia: in these devices, the anesthetic vial is closed in a compartment which, in case of breakage of the glass, prevents the pieces from coming out, since the pressure exerted for this particular anesthesia is higher.
THE INJECTION
For all the teeth of the Maxilla (upper jaw), the so-called plexic anesthesia is practiced. It simply consists in depositing the anesthetic "under the skin", ie inside the mucosa, roughly at the height of the presumed apex of the tooth's root to be treated.
The same anesthesia can be used in the incisors of the Mandible (lower arch), but it presents increasing difficulties as it is practiced on more posterior teeth: the reason is that the jaw bone that covers the roots grows progressively in thickness towards the back, for example on a molar the plexic anesthesia may not work well.
Many practitioners prefer to practice troncular anesthesia. This is an injection aimed at the inferior alveolar nerve, which is the one giving sensitivity to the whole mandible (one for the right side, one for the left). The injection happens in the internal mucosal area behind the last molar, almost towards the opening of the pharynx.
The effect is slightly delayed and includes anesthesia of the whole side of the mandible, up to half of the lower lip, and of the homologous half of the tongue (due to the proximity of the lingual nerve).
Whatever type of anesthesia is used, its effect can last from 1 hour to over 4 hours, depending on the situation. The anesthetic is disposed of in the urine, leaves no trace in the body and does not give any side effects or addiction.
