A double-blind, parallel non-randomized study is made to compare the heart rate and oxygen saturation levels in healthy patients subjected to lower third molar extractions under the effect of three different local anesthetics (4% articaine, 2% lidocaine, 2% mepivacaine) with the same epinephrine concentration (1:100,000). The patients were divided into three groups of 15 subjects each, according to the anesthetic employed. Heart rate and oxygen saturation were determined in each patient before and immediately after anesthetic injection, and again one minute after motor application to perform the ostectomy, at the start of force application to extract the tooth, on completing suture, and one week later at suture removal (the latter being taken as baseline reference). Blood pressure was also recorded, calculating the mean arterial pressure and the rate-pressure product (RPP) and pressure-rate quotient (PRQ). Only heart rate showed variations during the intervention, regardless of the local anesthetic used (based on a multifactor analysis of variance and considering statistical significance for p < 0.05). It may be concluded that none of the local anesthetics studied exert important effects upon the variables analyzed in healthy patients, though significant variations may arise due to the stress and/or anxiety associated to certain moments of lower third molar extraction.