Anesthetic duration of lidocaine with 10% dextran is comparable to lidocaine with 1:160 000 epinephrine after intraosseous injection in the rabbit.

OBJECTIVE: To compare the effects of 10% dextran and epinephrine on intraosseous injection with lidocaine in rabbits. STUDY DESIGN: Twenty male Japanese white rabbits were used. The effect of intraosseous injection was evaluated using an electromyogram (EMG) of the digastric muscle after electrical pulp stimulation. Two percent lidocaine alone (L), 2% lidocaine containing 1:80000 epinephrine (LE8), 2% lidocaine containing 1:160 000 epinephrine (LE16), and 2% lidocaine containing 10% dextran (LD) were tested. Electromyogram recordings were repeated before and 30 seconds, 1, 2, 3, 4, 5, 7, 10, 12, 15, and 20 minutes after the intraosseous injection. Thereafter, recordings were repeated every 5 minutes until the EMG recovered to the control value. RESULTS: There was no difference in the onset time between the 4 groups. The order of the duration of maximum effect was LE8 >LE16 = LD >or=L. The order of the duration of anesthesia was LE8 >LE16 = LD >L. CONCLUSION: Ten percent dextran potentiates local anesthetic effects of 2% lidocaine in intraosseous injection. The potency of 10% dextran is comparable to 1:160 000 epinephrine.