OBJECTIVESThe aim of this study was to determine the effect of single buccal infiltration of 4% articaine with either 1:100,000 (EP100) or 1:200,000 (EP200) epinephrine on pulpal blood flow (PBF), pulpal anesthesia and soft tissue anesthesia of maxillary first molars and second premolars in human subjects.MATERIALS AND METHODSFifteen healthy volunteers with intact maxillary first molars and second premolars received an infiltration of 4% articaine with either EP100 or EP200 at buccal aspect of maxillary first molars. The PBF, pulpal anesthesia and soft tissue anesthesia were assessed with a laser Doppler flowmeter (LDF), an electric pulp tester (EPT) and Aesthesiometer II, respectively.RESULTSArticaine (4%) with either EP100 or EP200 produced PBF reduction in maxillary first molars (injected teeth) by 68.09 and 69.83%, and produced PBF reduction in second premolars (adjacent teeth) by 76.81 and 75.02%, respectively at 15 min post injection. Duration of PBF returned to baseline was 159.00 ± 21.06 (EP100) and 159.00 ± 31.97 (EP200) min in the molars, and 161.00 ± 20.02 (EP100) and 159.00 ± 25.86 (EP200) min in the premolars. The onset of pulpal anesthesia was 2.80 ± 1.26 (EP100) and 3.07 ± 1.28 (EP200) min in the molars, and 2.13 ± 0.52 (EP100) and 2.40 ± 0.83 (EP200) min in the premolars; the duration of pulpal anesthesia was 74.53 ± 24.16 (EP100) and 76.27 ± 34.03 (EP200) min in the molars, and 82.53 ± 31.03 (EP100) and 75.60 ± 37.17 (EP200) min in the premolars. Buccal tissue anesthesia was found in both teeth (100%), but palatal anesthesia was achieved by 13.33% in the premolars and 6.67% in the molars for each solution.CONCLUSIONSSingle buccal infiltration to maxillary first molar produced PBF reduction and successful pulpal anesthesia, evaluated by EPT, in both first molar and second premolar. This anesthetic technique also produced high success of buccal tissue anesthesia, but demonstrated very low success for palatal tissue anesthesia.CLINICAL RELEVANCESingle buccal infiltration to maxillary first molar is potent enough for pulpal and buccal tissue anesthesia, except palatal tissue anesthesia, in both first molar and second premolar.