Effect of topical anesthesia on pain during infiltration injection and success of anesthesia for maxillary central incisors.

INTRODUCTION This study was performed to investigate the effect of topical anesthesia on pain during needle penetration and infiltration injection as well as the effect of pain during injection on success rate of anesthesia in maxillary central incisors. METHODS In a crossover double-blind study, 25 volunteers randomly received either topical anesthesia or placebo before infiltration injection with prilocaine for their maxillary central incisors in 2 separate appointments. The pain after needle penetration and during injection was separately recorded. An electric pulp tester was used to evaluate the success of the anesthetic injection. Data were analyzed by McNemar, Wilcoxon, and χ(2) tests. RESULTS Overall for 50 injections, 72% of the teeth had successful anesthesia. No significant difference was found between placebo and topical anesthetic groups for the pain of needle penetration as well as pain during injection (P > .05). The volunteers who reported moderate-to-severe pain during injection showed no significant difference in the success rate of anesthesia compared with those with no or mild pain during injections (P > .05). CONCLUSIONS Use of topical anesthesia had no significant effect on pain during either needle penetration or injection. Pain during injection had no significant effect on the success of anesthesia.