Thickness and fit of mouthguards according to heating methods

The purpose of this study was to examine the difference in the thickness and fit of mouthguards made by four different heating methods of the mouthguard sheet material. A Sports Mouthguard(®) of 3.8-mm thickness was used in this study. Four heating methods were performed. In one method, the sheet was heated only one side. In the other methods, one side of the sheet was heated first until the center of the sheet was displaced by 0.5 cm, 1.0 cm, and 1.5 cm from the baseline, and then turned upside down and heated. The sheets were adapted using a vacuum former when the heated sheets hung 1.5 cm from the baseline. We measured the thickness and fit of the mouthguard at the areas of the central incisor and first molar. The difference in thickness at the central incisor and first molar regions was analyzed by two-way anova. The difference in fit with different heating methods was analyzed by one-way anova. The results showed that the thickness of the mouthguard differed in the central incisor and first molar areas (P < 0.01 or P < 0.05), but not with the heating methods. The fit of the mouthguard at the central incisor and first molar areas was significantly different among the heating methods (P < 0.01 and P < 0.05). These results suggested that the fit of the mouthguard was superior when the heated surface of the sheet contacted the surface of the working model. This finding may help to fabricate accurate mouthguards.