Appropriate fabrication method for pressure-formed mouthguards using polyolefin sheets.

BACKGROUND/AIM: Polyolefin sheet mouthguards are usually formed in the same manner as ethylene-vinyl acetate sheet mouthguards. However, the heating condition of the polyolefin sheet for the pressure-forming process has not been determined. The aim of this study was to examine the appropriate heating condition for polyolefin sheet mouthguards when fabricated with the pressure-formed technique. MATERIALS AND METHODS: Mouthguard sheets of 3.0 mm polyolefin were pressure formed on working models at three heating temperatures: 90 degrees C, 105 degrees C, and 120 degrees C. The thickness of the mouthguard was measured at the labial surface of the central incisor, and the buccal and occlusal surfaces of the first molar. The fit of the mouthguard was examined at the central incisor and the first molar by measuring the distance between the mouthguard and the cervical margin of the working model. Differences in the thickness and fit of the mouthguards according to the heating conditions and the measured regions were analyzed using two-way analysis of variance. RESULTS: Mouthguard thickness varied among the measured regions of the central incisors and first molars (p < .01). The greatest thickness was found at the labial surface of the central incisor in mouthguards fabricated with the heating temperature of 90 degrees C (p < .01). The greatest thickness was found in mouthguards fabricated with the heating temperature of 105 degrees C at the buccal surface of the first molar (p < .01), and 105 degrees C or 120 degrees C at the occlusal surface of the first molar (p < .01). The fit was not significantly different among the three heating conditions both at the central incisor and the first molar. CONCLUSIONS: The appropriate heating condition for pressure-formed mouthguards using polyolefin sheets was 90 degrees C to maintain the mouthguard thickness at the anterior teeth area with proper fit.