Comparison of speed of action and injection discomfort of 4% articaine and 2% mepivacaine for pulpal anesthesia in mandibular teeth: A randomized, double-blind cross-over trial

OBJECTIVE: To compare the injection pain and speed of local anesthetic effect induced by tissue infiltration of mepivacaine 2% with epinephrine 1:100,000 versus articaine 4% with epinephrine 1:100,000 in securing mandibular first molar pulp anesthesia. MATERIALS AND METHODS: Totally, 25 patients were recruited in a crossover, randomized, double-blind study. Each subject received injections of mepivacaine 2% with epinephrine 1:100,000 as inferior alveolar nerve block (IANB) supplemented with either articaine 4% with epinephrine 1:100,000 (septocaine) or mepivacaine 2% buccal infiltration (BI) injection on two visits. The time of first numbness to associated lip, tongue and tooth was recorded by asking the participant directly and using electrical pulp tester. Anesthetic success was considered when two consecutive maximal stimulation on pulp testing readings without sensation. The patients rated the pain of infiltration using a 100 mm visual analog scale immediately after receiving each injection. The pain scores were compared using the paired t-test. RESULTS: There were significant differences in the meantime of first numbness to associated lip and tooth of volunteers between mepivacaine and articaine BI groups P = 0.03 and 0.002. Volunteers in articaine group recorded earlier lip and teeth numbness than those in mepivacaine group. There were significant differences between the mean pain scores for volunteers in the post IANB and postbuccal injection groups (t-test: P <0.001). Mepivacaine IANB injection was significantly more painful than articaine/mepivacaine buccal injection. CONCLUSIONS: About 4% articaine was faster than 2% mepivacaine (both with 1:100,000 adrenaline) in anesthetizing the pulps of lower molar teeth after BIs. Earlier lip and teeth numbness were recorded in articaine group. Articaine and mepivacaine BIs were more comfortable than mepivacaine IANB injections.