Lidocaine is a common local anesthetic dentists use to manage pain during various procedures. This medication temporarily blocks nerve signals in a specific area of the mouth, allowing patients to undergo treatments comfortably. Its administration is precise, targeting specific anatomical locations to induce reversible numbness for procedures from simple fillings to complex extractions.
Common Injection Sites for the Upper Jaw
For dental procedures in the upper jaw, dentists typically use infiltration anesthesia. This method involves injecting lidocaine directly into the gum tissue near the tooth or teeth requiring treatment. The upper jaw bone, known as the maxilla, is relatively porous, allowing the anesthetic solution to diffuse easily through the bone and reach the nerve endings surrounding the tooth.
Infiltration injections are frequently applied to the front teeth, including the incisors, canines, and premolars. The anesthetic is deposited into the soft tissues of the vestibule, the area between the cheek or lip and the gums, directly above the root tips of the target teeth. For upper molars, a palatal injection into the roof of the mouth may also be used to numb the gum tissue on the tongue side.
Common Injection Sites for the Lower Jaw
Numbing the lower jaw, or mandible, requires a different approach due to its denser bone structure. Unlike the porous maxilla, the compact nature of the mandible makes it difficult for anesthetic solutions to diffuse through the bone to reach individual teeth. Dentists employ nerve block anesthesia for procedures involving lower teeth. This technique involves injecting the anesthetic near a main nerve trunk, which then numbs a larger region supplied by that nerve.
The most common nerve block in dentistry is the Inferior Alveolar Nerve Block, which numbs most of the teeth on one side of the lower jaw, along with the lip and tongue on that same side. The injection site for this block is typically located near the back of the jaw, behind the last molar, targeting the inferior alveolar nerve as it enters the mandibular canal. Other lower jaw injections include the buccal nerve block for numbing the cheek-side gums of lower molars, and the mental nerve block, which anesthetizes the lower lip and chin, often used for procedures on the lower front teeth.
Preparing for the Injection and What to Expect
Before administering the lidocaine injection, dentists prepare the area to enhance patient comfort. A topical numbing gel or spray is applied to the injection site on the gum tissue. This topical anesthetic works superficially to desensitize the mucous membrane, making the initial prick of the needle less noticeable.
During the actual injection, patients typically report feeling a brief pinch or pressure as the anesthetic solution is slowly delivered. This pressure is a normal part of the process and indicates the medication is being properly distributed. As the lidocaine begins to take effect, a tingling or warm sensation may be experienced, which soon progresses to a feeling of complete numbness. This onset usually occurs within a few minutes, depending on the specific injection site and the type of anesthetic used.
The numbness from lidocaine typically lasts for several hours, ranging from two to four hours, though this can vary based on the individual and the amount of anesthetic administered. During this period, it is common to experience temporary effects such as difficulty speaking clearly or eating without biting the lip or tongue. Patients are often advised to be cautious with hot foods and beverages until the numbness fully subsides.