Abstract
Purpose: The manufacturing process ofmouthguard sheets is either by extrusion or injection molding. The aim of this study was to investigate the thickness of mouthguard sheets after formationinrelationto the ditched mouthguard sheet and the manufacturing process of the mouthguard sheet material.
Methods: Two manufacturing processes of mouthguard sheets were compared: extrusion molding or injection molding. The sheets were formed by vacuum former being heated until they sagged 15 mm from the baseline. Thickness was measured by a measuring device at the parts fitted to the anterior teeth (labial surface and incisal edge) and the posterior teeth (buccal surface, central groove, buccal cusp, and lingualcusp). Two shapes of the sheet were compared: ordinary sheet and ditched sheet. The difference in the ratio of change of thickness, depending on the manufacturing process, and the shapes of the sheet were analyzed by two-factor ANOVA and Tukey's test.
Results: The part of the sheet fitted to the anterior teeth (labial surface and incisal edge) and to the posteriorteeth (buccal surface, central groove, and lingual cusp) of the ditched sheet on the extrusion molding was thicker than that of an ordinary sheet. It was not significant differences in the thickness by the sheet's shape on injection molding.
Conclusion: The present study suggests that the thickness of the mouthguard sheet in this study used after vacuum forming was affected by the shape of the sheet. Further, the ditched sheet could secure thickness in the parts of the anterior teeth and posterior teeth of the mouthguard sheet on the extrusion molding.
