Effect of Eutectic Mixture of Local Anesthetics on Pain Perception During Scaling by Ultrasonic or Hand Instruments: A Masked Randomized Controlled Trial

Background: The aims of this study are to evaluate the efficacy of a eutectic mixture of local anesthetic (EMLA) cream on pain perception during scaling and to compare the intensities of pain provoked by hand and ultrasonic instruments. Methods: Forty subjects with chronic gingivitis or periodontitis were enrolled in the study. In this randomized, split-mouth, controlled, masked clinical trial, each of the four quadrants in subjects was randomly assigned to receive one of the following protocols: scaling with an ultrasonic scaler with or without the application of the EMLA cream or scaling with a Gracey curet with or without the application of the EMLA cream. Pain levels after each quadrant of scaling were assessed with a visual analog scale (VAS; 0 to 100 mm) and verbal rating score (VRS; 0 to 4). All subjects were recalled to detect any complications after 24 hours. Results: The mean VAS and VRS when EMLA cream was applied (18.39 +/- 14.47 mm and 0.95 +/- 0.69) were significantly lower (P < 0.001 for VAS and VRS) compared to when EMLA cream was not used (26.54 +/- 16.46 mm and 1.30 +/- 0.75). The mean VAS and VRS of the ultrasonic scaler group (20.43 +/- 16.40 mm and 0.98 +/- 0.76) were significantly lower (P=0.024 for VAS; P=0.003 for VRS) than those of the Gracey curet group (24.50 +/- 15.17 mm and 1.28 +/- 0.69). None of the subjects showed adverse effects after EMLA-cream application. Conclusion: Although most patients experienced limited pain during scaling, a significant reduction of pain is achieved by using EMLA cream and ultrasonic scaler. J Periodontol 2011;82:259-266.