The anesthetic efficacy of articaine in buccal infiltration of mandibular posterior teeth

BACKGROUND: The authors conducted a prospective, randomized, double-blind, crossover study comparing the degree of pulpal anesthesia achieved by means of mandibular first molar buccal infiltrations of two anesthetic solutions: 4 percent articaine with 1:100,000 epinephrine and 2 percent lidocaine with 1:100,000 epinephrine. METHODS: Each of 60 blinded adult subjects randomly received two buccal infiltrations at the first molar site: one cartridge of 4 percent articaine with 1:100,000 epinephrine at one appointment and one cartridge of 2 percent lidocaine with 1:100,000 epinephrine at another appointment. The injections were administered during two separate appointments spaced at least one week apart. The authors used an electric pulp tester to assess the first and second molars and the first and second premolars for pulpal anesthesia in three-minute cycles for 60 minutes. They considered anesthesia to be successful when they obtained two consecutive pulp test readings of 80 (meaning the subject evidenced no response at the maximum output on the pulp tester). RESULTS: With the lidocaine formulation, successful pulpal anesthesia ranged from 45 to 67 percent. With the articaine formulation, successful pulpal anesthesia ranged from 75 to 92 percent. There was a significant difference (P < .05) in anesthetic success between the lidocaine and articaine formulations for each of the four teeth. Pulpal anesthesia declined slowly over 60 minutes with both formulations. CONCLUSION AND CLINICAL IMPLICATIONS: For a mandibular buccal infiltration of the first molar, 4 percent articaine with 1:100,000 epinephrine will result in a higher success rate than will 2 percent lidocaine with 1:100,000 epinephrine, but the duration of pulpal anesthesia will decline over 60 minutes with either formulation.