Anesthetic efficacy of the intraosseous injection of 0.9 mL of 2% lidocaine (1:100,000 epinephrine) to augment an inferior alveolar nerve block.

OBJECTIVE

The purpose of this study was to determine the anesthetic efficacy of an intraosseous injection of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine to augment an inferior alveolar nerve block in mandibular posterior teeth.

STUDY DESIGN

With the use of a repeated-measures design, each of 38 subjects randomly received one or the other of 2 combinations of injections at 2 separate appointments. The combinations were inferior alveolar nerve block + intraosseous injection (on the distal of the second premolar) through use of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine and inferior alveolar nerve block + mock intraosseous injection. The first molar, second premolar, and second molar were blindly tested with an Analytic Technology pulp tester at 2-minute cycles for 120 minutes postinjection. Anesthesia was considered successful when 2 consecutive 80 readings were obtained.

RESULTS

One hundred percent of the subjects had lip numbness with the inferior alveolar nerve block + intraosseous injection combination technique. The respective anesthetic success rates for the inferior alveolar nerve block + mock intraosseous injection combination and the inferior alveolar nerve block + intraosseous injection combination were 60% and 100% for the second premolar, 71% and 95% for the first molar, and 74% and 87% for the second molar. The differences were significant (P < .05) for the second premolar through 50 minutes and for the first molar through 20 minutes. There were no significant (P > .05) differences for the second molar. Sixty-eight percent of the subjects had a subjective increase in heart rate with the intraosseous injection.

CONCLUSIONS

The results of this study indicate that the supplemental intraosseous injection of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine, given distal to the second premolar, significantly increased the success of pulpal anesthesia in the second premolar (for 50 minutes) and first molar (for 20 minutes) in comparison with the inferior alveolar nerve block alone. The intraosseous injection did not statistically increase success in the second molar.