Study on the Thickness of Mouthguard Sheet after a Vacuum-Forming Process—The Influence of Mouthguard Sheet Material—

Purpose: The effectiveness of a mouthguard used after stomatognathic injury related to sports depends on what the guard is made of and its thickness. The aim of this study was to investigate the thickness of a mouthguard after formation from the mouthguard sheet. Methods: Three mouthguard sheet materials were compared. They were EVA: the material being ethylene-vinyl acetate copolymer; OL: olefin copolymer; and OS: polyolefin-polystyrene copolymer. Cross-stripes (10×10 mm) were printed on mouthguard sheets. The thickness of each cross-stripe area was measured by a measuring device. The working model was trimmed to a height of 20 mm at the incisal edge of the upper central incisor, and to 15 mm at the medial buccal cusp of the upper first molar. The sheets were heated by vacuum former until they sagged 15 mm from the baseline. The differences in the ratio of thickness change of the three mouthguard sheet materials after forming was analyzed by one-way ANOVA and Tukey test. Results: The thickness of the sheet fitted to the anterior teeth, palate, and posterior teeth of OL sheet was thinnest, and that of OS sheet was thickest. Conclusions: This study suggests that the thickness of the sheet after vacuum forming was affected by the mouthguard sheet materials, and that the polyolefin-polystyrene copolymer sheet could secure the thickness of the