Anesthetic efficacy of ropivacaine in maxillary anterior infiltration

OBJECTIVE: The purpose of this prospective, randomized double-blind study was to evaluate and compare the anesthetic efficacy of 0.5% ropivacaine with 1:200,000 epinephrine, of 0.5% ropivacaine, and of 0.5% bupivacaine with 1:200,000 epinephrine in maxillary lateral incisor infiltrations. STUDY DESIGN: Forty subjects randomly received, in a double-blind manner, 3 infiltrations at 3 separate appointments, in a repeated-measures design. The injections consisted of an infiltration of 1.8 mL of 0.5% ropivacaine plain, an infiltration of 1.8 mL of 0.5% ropivacaine with 1:200,000 epinephrine, and an infiltration of 1.8 mL of 0.5% bupivacaine with 1:200,000 epinephrine (control solution). The maxillary lateral incisor pulpal anesthesia was evaluated with an electric pulp tester at 2-minute cycles for 90 minutes after injection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained. The duration of pulpal anesthesia was recorded as the last 80 reading. RESULTS: One hundred percent of the subjects had lip numbness with all solutions. The anesthetic success rates for ropivacaine plain, ropivacaine with epinephrine, and bupivacaine with epinephrine were 68%, 75%, and 80%, respectively. There were no significant differences (P >.05) among the solutions. The duration of pulpal anesthesia (80 readings) for ropivacaine plain, ropivacaine with epinephrine, and bupivacaine with epinephrine was 13 minutes, 33 minutes, and 33 minutes, respectively. Ropivacaine plain had a significantly shorter duration of pulpal anesthesia than ropivacaine with epinephrine. CONCLUSIONS: We concluded that 0.5% ropivacaine with 1:200,000 epinephrine was equivalent to 0.5% bupivacaine with 1:200,000 epinephrine in pharmacologic action. The duration of pulpal anesthesia was less for ropivacaine without epinephrine. Ropivacaine with epinephrine has the potential to replace bupivacaine with epinephrine in clinical dental practice because of the decreased potential for cardiac and central nervous system toxicity.