Injection pain and postinjection pain of the palatal-anterior superior alveolar injection, administered with the Wand Plus system, comparing 2% lidocaine with 1:100,000 epinephrine to 3% mepivacaine.

Purpose: The purpose of this prospective, randomized, double-blind study was to compare injection pain and postinjection pain of 2% lidocaine with 1:100,000 epinephrine and 3% mepivacaine using the computer-assisted Wand Plus injection system to administer the palatal-anterior superior alveolar (P-ASA) injection. Additionally study was done to determine if the use of topical anesthetic decreased the pain of needle insertion with the P-ASA injection.

Study Design: Using a crossover design, 40 subjects randomly received, in a double-blind manner, P-ASA injections of 1.4 mL of 2% lidocaine with 1:100,000 epinephrine and 1.4 mL of 3% mepivacaine, at 2 separate appointments. The P-ASA injection was administered, utilizing the Wand Plus system, 6 to 10 mm into the incisive canal located lingual to the central incisors. The pain of needle insertion, needle placement, solution deposition and postinjection pain were recorded on a Heft-Parker visual analog scale for the 2 P-ASA injections. Eighty injections were randomly administered in the study, 40 using topical anesthetic gel and 40 using a placebo gel.

Results: For needle insertion, 30% of the subjects reported moderate/severe pain with the lidocaine solution and 43% reported moderate/severe pain with the mepivacaine solution. There was no significant difference (P > .05) between the topical and placebo groups. For needle placement into the incisive canal, 54% of the subjects reported moderate/severe pain with the lidocaine solution and 58% reported moderate/severe pain with the mepivacaine solution. For anesthetic solution deposition, 8% of the subjects reported moderate pain with the lidocaine solution and 12% reported moderate pain with the mepivacaine solution. There were no significant differences (P > .05) between the lidocaine and mepivacaine solutions. Regarding postinjection pain, when anesthesia wore off on the day of the injection, 20% of the subjects reported moderate/severe pain with the lidocaine solution and 14% reported moderate/severe pain with the mepivacaine solution. Pain ratings decreased over the next 3 days. There were no significant differences (P > .05) between the lidocaine and mepivacaine solutions. Postinjection, 12% and 18% of the subjects experienced temporary numbness/paresthesia of the incisive papilla with the lidocaine and mepivacaine solutions, respectively. Twenty percent and 28% of the subjects had incisive papilla swelling or soreness with the lidocaine and mepivacaine solutions, respectively. There were no significant differences (P > .05) between the lidocaine and mepivacaine solutions.

Conclusions: The P-ASA injection of 1.4 mL of 2% lidocaine with 1:100,000 epinephrine or 3% mepivacaine, administered with the Wand Plus, has the potential to be a painful injection. The use of topical anesthetic did not significantly reduce pain of needle insertion when compared to a placebo. The incidence of postinjection pain, temporary numbness/paresthesia, and incisive papilla swelling or soreness would indicate that some pain and problems occur with the P-ASA technique, regardless of whether 2% lidocaine with 1:100,000 epinephrine or 3% mepivacaine is used.