ANESTHETIC EFFICACY OF THE INTRAOSSEOUS INJECTION OF 0.9 ML OF 2-PERCENT LIDOCAINE (1 100,000-EPINEPHRINE) TO AUGMENT AN INFERIOR ALVEOLAR NERVE BLOCK/

Objective. The purpose of this study was to determine the anesthetic e fficacy of an intraosseous injection of 0.9 mL of 2% lidocaine with 1: 100,000 epinephrine to augment an inferior alveolar nerve block in man dibular posterior teeth.Study design. With the use of a repeated-measu res design, each of 38 subjects randomly received one or the other of 2 combinations of injections at 2 separate appointments. The combinati ons were inferior alveolar nerve block + intraosseous injection ton th e 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 i ntraosseous injection. The first molar, second premolar, and second mo lar were blindly tested with an Analytic Technology pulp tester at 2-m inute 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 alv eolar nerve block + intraosseous injection combination technique. The respective anesthetic success rates for the inferior alveolar nerve bl ock + mock intraosseous injection combination and the inferior alveola r nerve block + intraosseous injection combination were 60% and 100% f or the second premolar, 71% and 95% for the first molar, and 74% and 8 7% for the second molar. The differences were significant (P > .05) fo r the second premolar through 50 minutes and for the first molar throu gh 20 minutes. There were no significant (P > .05) differences for the second molar. Sixty-eight percent of the subjects had a subjective in crease in heart rate with the intraosseous injection. Conclusions. The results of this study indicate that the supplemental intraosseous inj ection of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine, given dis tal to the second premolar, significantly increased the success of pul pal 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 succ ess in the second molar.