Purpose: The purpose of the present study was to evaluate some important mechanical properties of an experimental silicone material (PM1) to assess its potential as a mouthguard material. Materials and Methods: The hardness, tear strength, tensile properties, and energy absorption properties of the silicone material were determined and compared with those of 2 commercially available materials (Bioplast, a polyvinylacetate polyethylene, and Polyshield, a silicone). Results: Bioplast was significantly harder than Polyshield and PM1. Polyshield was significantly harder than PM1. Bioplast had a significantly higher tear strength than both Polyshield and PM1. The tensile strength of Bioplast was significantly greater than that of Polyshield and PM1. PM1 had a significantly higher tensile strength than Polyshield. Bioplast had a significantly lower energy absorption capacity at 500 N than both Polyshield and PM1, with PM1 having a significantly higher value than Polyshield. At 1,000 and 1,500 N, Bioplast had a significantly higher energy absorption than both Polyshield and PM1. Conclusion: It was concluded that PM1 showed better energy absorption properties than Polyshield and better energy absorption properties than Bioplast at lower impact forces. PM1 was softer and had better tear and tensile properties than Polyshield. The results of the present study suggest that the new material has a good potential for use as a mouthguard material. Int J Prosthodont 2000;13:416-419.