The purpose of this study was to compare the degree of anesthesia obtained with 2% lidocaine with three different concentrations of epinephrine for inferior alveolar nerve block. Using a repeated measures design, 30 subjects randomly received an inferior alveolar injection using masked cartridges of each solution at three successive appointments. The first molar, first premolar, lateral incisor, and contralateral canine (control) were blindly tested with an Analytic Technology pulp tester at 3-min cycles for 50 min. No statistically significant differences in success and failure were found among the 1:50,000, 1:80,000, and 1:100,000 concentrations of epinephrine.