Basic research to propose a new design of laminated mouthguard-Effect of lamination order on thickness

Mouthguard thickness influences the protection ability from orofacial trauma. The aim of this study was to propose a new design for mouthguards and to evaluate the effect of the lamination order on the thicknesses of mouthguards.

Mouthguard sheets of 2.0-mm and 4.0-mm ethylene vinyl acetate were used. The sheets were pressure formed using a pressure former. Two lamination conditions were examined: The condition 24P used the 2.0-mm sheet as the first layer and 4.0-mm sheet as the second layer. The condition 42P used the 4.0-mm sheet as the first layer and 2.0-mm sheet as the second layer. The first layer was trimmed to cover only the anterior region, and then the second layer was formed over the first layer. Mouthguard thickness was measured using a measuring device at the labial surface of the central incisor, plus the buccal and occlusal surfaces of the first molar. Differences in thickness by measurement region of mouthguards formed under different lamination conditions were analyzed by two-way analysis of variance.

Mouthguard thickness differed among the regions at the central incisors and the first molars (p < .01). The thickness at the labial surface of the central incisor became statistically significantly larger with the 42P condition (3.38 mm) than with the 24P condition (3.30 mm) (p < .05). The thickness at the buccal and occlusal surfaces of the first molar became statistically significantly larger with the 24P condition (2.25 mm and 2.72 mm, respectively) than with the 42P condition (1.23 mm and 1.44 mm, respectively) (p < .01).

The results suggest that the combination of the 2.0-mm and 4.0-mm sheets could obtain the necessary thickness for the prevention at the labial surface of the central incisor and buccal surface of the first molar.