Articaine Infiltrations of the Mandibular Lateral Incisor-Is It Volume or Location of the Infiltrations That Affect Success? A Prospective, Randomized Crossover Study.

INTRODUCTION: A combination labial infiltration (1.8 mL) plus lingual infiltration (1.8 mL) of 4% articaine with 1:100,000 epinephrine in the mandibular lateral incisor was found superior to a labial infiltration of 1.8 mL of the same solution. However, it is not known whether the volume or the location had the greatest effect. Therefore, the purpose of this prospective, randomized crossover study was to determine the anesthetic efficacy of a labial infiltration of a 3.6 mL volume of 4% articaine with 1:100,000 epinephrine compared with labial infiltration (1.8 mL) plus lingual infiltration (1.8 mL) of 4% articaine with 1:100,000 epinephrine in the mandibular lateral incisor.

METHODS: One hundred subjects randomly received 2 sets of injections, using 4% articaine with 1:100,000 epinephrine, consisting of labial and lingual infiltrations of 1.8 mL (3.6 mL total) and 2 labial infiltrations of 1.8 mL (3.6 mL total) of the mandibular lateral incisor in 2 separate appointments. Electric pulp testing was used to determine anesthetic success (highest 80/80 reading). The data were analyzed statistically.

RESULTS: The labial and lingual combination exhibited a significantly higher anesthetic success rate (97%) when compared with the 2 labial infiltrations (74%) and had significantly higher 80/80s readings from 1 minute to 58 minutes.

CONCLUSIONS: Within the limitations of this clinical study, a combination labial plus lingual infiltration using a 3.6-mL volume of 4% articaine with 1:100,000 epinephrine significantly increased pulpal anesthetic success for the mandibular lateral incisor when compared with a labial infiltration using a 3.6-mL volume of articaine. Therefore, location of the infiltrations was more important than volume.