Clinical investigation of potency and onset of different lidocaine sprays for topical anesthesia in dentistry.

Abstract

The clinical effects of three lidocaine-containing solutions with and without frigen (freon-113) as a propellant, after different waiting periods, and with different dosages applied were investigated in 130 outpatients who were undergoing dental treatment in the maxilla under local anesthesia. They were divided randomly into five groups (A through E): (A) Xylocaine spray with frigen, two applications (20 mg lidocaine); (B) Xylestesin spray with frigen, two applications (14 mg lidocaine); (C) Xylestesin spray with frigen, three applications (21 mg lidocaine); (D) Xylestesin pump spray without frigen, two applications (14 mg lidocaine); and (E) no topical anesthesia. They were further divided into 12 subgroups to evaluate waiting periods between the application of the topical anesthesia and the injection (1, 2, or 3 minutes). Patients assessed the pain of the injection, intensity of numbness, and intensity of the taste on a visual analog scale; they also assessed the pain of the injection compared to former injections. Pain during injection was reduced by topical application of lidocaine. A waiting period of 2 minutes proved to be sufficient and can be justified to avoid impatience and increased numbness in patients. However, a 3-minute waiting period may be appropriate for sensitive patients. An increase in the dosage failed to show better analgesia. The pump spray without frigen proved to be effective.