Background/aim: Mouthguard sheet materials such as ethylene vinyl acetate and polyolefin have been used commonly. However, the change of the sheet temperature during heating of the polyolefin has not been determined. The aim of this study was to examine the change of the sheet temperature during heating and to examine the vacuum-formed mouthguard characteristics for the sheet materials.
Materials and methods: The mouthguard materials used were 4.0-mm sheets of ethylene vinyl acetate and polyolefin. The sheet temperature of the two materials was measured when the center of the sheet was displaced by 10, 15, and 20 mm from the baseline after heating. Sheet temperature differences by sheet materials were analyzed by two-way analysis of variance. The sheets were vacuum-formed when the heating temperatures reached 100°C using ethylene vinyl acetate sheet and polyolefin sheet. Mouthguard thickness and fit was measured at the central incisor and the first molar. Differences in the thickness and fit between the sheet materials were analyzed by two-way analysis of variance.
Results: The sheet temperature of ethylene vinyl acetate sheets became higher as the hanging distance became larger (P < 0.05), but that of polyolefin sheets was not different. The thicknesses of the vacuum-formed mouthguard at the central incisor and the first molar were greater in the mouthguards formed by ethylene vinyl acetate sheets than that with polyolefin sheets (P < 0.01 or P < 0.05). The fit of the mouthguard was not different between mouthguards formed by ethylene vinyl acetate sheets and that formed by polyolefin sheets.
Conclusions: The change of mouthguard sheet temperature during heating was different between ethylene vinyl acetate and polyolefin sheets. The ethylene vinyl acetate sheets maintained the vacuum-formed mouthguard thickness in comparison with the polyolefin sheets with a better fit.
Keywords: formation; mouthguard; temperature.
© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.