The aim of the present study was to evaluate the effectiveness soft tissue anesthesia and comfort during infiltrative anesthesia.
Method:
Following ethical approval, twelve healthy subjects were selected for a pilot study. The subjects received a buccal infiltration of 0.9ml of 2% lidocaine with 1:100.000 epinephrine in the right-upper canine. All subjects were submitted to four sessions randomly assigned: Basal (without any topical anesthesia or conscious sedation), Lido (topical anesthesia with 5% lidocaine), Benzo (topical anesthesia with 20% benzocaine), N2O (no topical anesthesia but nitrous oxide sedation). Anxiety was assessed with faces anxiety scale. Pain was measured by visual analogic scale right after the puncture (VAS1) and right after the injection of local anesthetic (VAS2). Data were analyzed by Kruskal-Wallis and Student-Newman-Keuls tests (α=5%).
Result:
The anxiety scale showed that the subjects had low levels of anxiety (score 1) and there were no difference among the sessions (p=0.699). However, VAS1 showed statistically significant differences among the four sessions (p=0.0001), being the values (median, min-max values) higher in the basal (4, 0-5,6) and benzo (3.35, 0.3-5) sessions. Lido session (1.8, 0-3.9) showed no difference in relation to N2O (0, 0-0.8) (p=0.0695). VAS2 showed that N2O session showed statistically significant differences (p=0.001) from the other sessions, while basal, benzo and lido sessions showed no difference.
Conclusion:
Nitrous oxide sedation was able to reduce the pain during puncture and injection of anesthetic solution. Lidocaine was effective to alleviate puncture pain, but not the injection discomfort. In this study benzocaine failed to reduce pain during injection.