Objectives: The aim of this study was to compare the onset and duration of pulpal anesthesia by maxillary infiltration using 2% lidocaine with 1:100,000 epinephrine, 4% articaine with 1:200,000 epinephrine, and 4% articaine with 1:100,000 epinephrine. Method and Materials: Twenty healthy patients randomly received 1.8 mL of one of the three local anesthetics during operative dentistry procedures of low complexity on three maxillary posterior teeth. Onset and duration were determined using an electric pulp tester. Results: The mean values for pulpal onset were 2.8, 1.6, and 1.4 minutes and for pulpal duration were 39.2, 56.7, and 66.3 minutes, respectively, for 2% lidocaine with 1:100,000 epinephrine, 4% articaine with 1:200,000 epinephrine, and 4% articaine with 1:100,000 epinephrine. Statistical analysis by the Kruskal-Wallis nonparametric test showed significant differences with better results (shorter onset and longer duration periods) for both articaine solutions compared with the lidocaine solution. Although 4% articaine with 1:100,000 epinephrine clinically presented the shortest onset and the longest duration periods, there was no statistically significant difference between the articaine solutions. Conclusion: Both articaine solutions produced shorter onset and longer duration of pulpal anesthesia by maxillary infiltration than the lidocaine solution did. Statistical analysis did not confirm better clinical results of 4% articaine with 1:100,000 epinephrine than with 4% articaine with1:200,000 epinephrine. Keywords: articaine, dental anesthesia, dental pulp, epinephrine, lidocaine