Characterization of mouthguards: Impact performance

It is difficult to characterize the impact behavior of mouthguards on the basis of their components. Impact behavior tests should be performed on mouthguard formed to simulate their intra-oral performance. The aim of this study was to compare the impact behavior of six models of mouthguards using a standardized experimental protocol.

Four commercially available mouth-formed mouthguards (SDI™, Gel Nano™, Opro Shield Gold™ and Kipsta R300™), one mouth-formed mouthguard prototype and one custom-made mouthguard were tested. The procedures recommended by the manufacturers (injecting procedure for custom-made mouthguard and "boil-and-bite" procedures for mouth-formed mouthguards) were used to adapt five samples per model on steel jaws. Impact performances were assessed according to labial aspect thickness and maximum contact load (FMax) during impact using a drop tower.

SDI™ and Opro Shield Gold™ had the thinnest labial aspect thickness (P<.01), followed by the Gel Nano™ and the Kipsta R300™ (P<.01) with a thickness of about 3 mm. The prototype and custom-made mouthguard were thicker (almost 4 mm). The custom-made mouthguard, the Kipsta R300™ and the prototype had the best impact performances, but the labial aspect thickness of the Kipsta R300™ was significantly lower than that of the custom-made mouthguard and the prototype. Analysis of force curves and position of the mouthguard on the impacted zone showed that the Kipsta R300™ was less well adapted.

Thickness and impact performance are not sufficient criteria to characterize performance of mouthguards.