Mouthguard seems to be the best protection mean against dental injuries for sport application. The purpose of this study is to compare three different mouth guards under different condition of impacts closed to those observed on real-life shock loading. Specific devices were designed, firstly to pre-load and to form the mouthguard as it specified by the manufacturer; secondly to perform the different impacts on a very specific impact apparatus. Force and displacement were recorded as function of time. Those measurements were supplemented by a high speed video device to visualize the effect of the impact during the loading. A dissipated energy analysis was also performed.