Abstract

Previous studies have shown declining rates of pulpal anesthesia over 60 minutes when a cartridge of 4% articaine is used with 1∶100,000 epinephrine for buccal infiltration in the mandibular first molar. The authors conducted a prospective, randomized, single-blind, crossover study comparing the degree of pulpal anesthesia obtained with 2 sets of mandibular first molar buccal infiltrations, given in 2 separate appointments, to 86 adult subjects: an initial infiltration of a cartridge of 4% articaine with 1∶100,000 epinephrine plus a repeated infiltration of the same anesthetic and dose given 25 minutes following the initial infiltration versus an initial infiltration of a cartridge of 4% articaine with 1∶100,000 epinephrine plus a mock repeated infiltration given 25 minutes following the initial infiltration. The authors used an electric pulp tester to test the first molar for anesthesia in 3-minute cycles for 112 minutes after the injections. The repeated infiltration significantly improved pulpal anesthesia from 28 minutes through 109 minutes in the mandibular first molar. A repeated infiltration of a cartridge of 4% articaine with 1∶100,000 epinephrine given 25 minutes after an initial infiltration of the same type and dose of anesthetic significantly improved the duration of pulpal anesthesia, when compared with only an initial buccal infiltration, in the mandibular first molar.