Efficacy and Safety of Administration of Different Doses of 4% Articaine.

The goal of this triple-blind randomized clinical trial is to compare the efficacy and safety of administering one cartridge (1.8 mL) versus two cartridges of articaine 4% with epinephrine 1:100,000 for lower third molar extraction using the inferior alveolar nerve block technique.

The main questions it aims to answer are:

* The injection of 3.6 ml of 4% articaine 1:100,000 has a higher anesthetic efficacy than a single injection of 1.8 ml of the same anesthetic. * The injection of 3.6 ml of 4% articaine 1:100,000 has a higher rate of adverse effects than a single injection of 1.8 ml of the same anesthetic. * The injection of 3.6 ml of 4% articaine 1:100,000 has a greater alteration of heart rate, oxygen saturation and systolic and diastolic blood pressure than a single injection of 1.8 ml of the same anesthetic.

The investigator (XA) will perform the anesthetic technique.

* The investigator will administer a first anesthesia for NDI block with a cartridge of 4% articaine anesthetic at 1:100,000 . At the end, an envelope containing the assignment to the experimental or control group will be opened.

* In the control group, a single cartridge of anesthetic (1.8 mL of articaine 4% 1:100,000) will be injected and a second puncture will be simulated, contacting the syringe without the needle, in the same area, counting up to 30 seconds. * In the experimental group two anesthetic cartridges of articaine 4% 1:100,000 will be administered with the direct technique for the inferior alveolar nerve block. * After checking Vincent's sign, the vestibular (buccal nerve) infiltration will be performed in both groups with half a cartridge (0.9 ml) of the same anesthetic solution. * The latency of the anesthetic effect will be measured using a pulpometer. * Subsequently, a student of the Master's Degree in Oral Surgery of the University of Barcelona will perform the surgical intervention. The surgeons in charge of performing the extraction will not know to which group each patient belongs. * The collection of the variables and the postoperative controls will be carried out by the researcher who has not performed the anesthetic technique and who will not know the study group to which the patient belongs.