Laboratory evaluation of mouthguard material

The aim of this study was to evaluate, in vitro, the EVA material (polyviny lacetate-polyethylene copolymer) most commonly used in the fabrication of m outhguards and thus to help understand mouthguard performance and to improv e mouthguard design. The material was tested for tensile strength, elongati on, hardness and water absorption using specimens and tests described by th e American Society for Testing and Materials Standards. Standard EVA sheets of 1, 2, 3 and 5 mm. thickness were prepared. With increase in the thickne ss of the material, both the ultimate tensile strength and the elongation w ere decreased. The hardness and water absorption were unaffected. It was co ncluded that, overall, the thicker 5 mm EVA material was recommended for mo uthguards as it displayed the least deformation to load and performed equal ly as well in the tests as other thicknesses.