Laboratory evaluation of new shock absorbent material for mouth guards

This study evaluated the physicomechanical properties of photopolymerized urethane diacrylate "Lite Line" as a new mouth guard material compared with heat cured silicone rubber "Molloplast-B" as a commercial product used to fabricate mouth guards. The tests chosen were those that measured tensile strength, elongation percent modulus of elasticity, energy absorption, tear strength, surface hardness and abrasion resistance of both materials as they were considered the properties of greatest importance to the function of a mouth protector. The appropriate standardized test procedures, which were established by the American Society for Testing and Materials [ASTM] were followed in this study. From the results of this study it was concluded that, the photopolymerized urethane diacrylate Lite Line showed higher mean value of tensile strength, elastic modulus and surface hardness with the lowest percent of elongation. Lite Line had better shock absorbing properties compared to Molloplast-B, so maximum protection can be achieved by the use of Lite Line for fabrication of mouth guards. There were no significant differences between the Lite Line and Molloplast-B in the tear strength values. Surface roughness mean values showed significant differences between the two tested materials before and after abrasion resistance test. Molloplast-B appeared with smoother surface than Lite Line following abrasion test as shown in SEM photomicrographs. In general, the physicomechanical properties of the tested materials were within the accepted range of variation for a mouth guard material