Takahashi M, Bando Y. Examination of thermoforming techniques to secure mouthguard thickness of the labial and buccal sides with a single sheet: An in vitro study.
Dent Traumatol 2022;
38:332-339. [PMID:
35179823 DOI:
10.1111/edt.12739]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/04/2022] [Accepted: 02/09/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND/AIM
Mouthguards must have an appropriate thickness to prevent oral trauma during sports. The aim of this study was to establish a thermoforming technique to secure the labial and buccal thicknesses of the mouthguard with a single sheet.
MATERIALS AND METHODS
Mouthguards were thermoformed using 4.0-mm thick sheets manufactured by extrusion molding, a plaster model, and a vacuum forming machine. Two sheet installation conditions were compared: the sheet extrusion direction was either parallel (P) or vertical (V) to the model's centerline. In each extrusion direction, two forming conditions were compared: (1) the sheet was formed when it sagged 15-mm below the sheet frame at the top of the post (control group; C-P, C-V); and (2) the sheet frame was lowered 50-mm below the ordinary level and heated, the frame was lowered when it sagged 15-mm, and the model was moved forward 20-mm before formation (experimental group; E-P, E-V). Difference in thickness (incisal edge, labial surface, cusp, and buccal surface) due to sheet extrusion direction and forming conditions were analyzed by two-way ANOVA and the Bonferroni method.
RESULTS
At all measurement sites, a significant difference in thickness depending on the sheet extrusion direction was observed in the experimental group (p < .01), but not in the control group. Difference in thickness depending on the forming condition was observed at all measurement sites, and the thickness was in the order C-P, C-V < E-P < E-V. Thicknesses of E-P and E-V were 3.01 ± 0.03 mm and 3.25 ± 0.02 mm on the labial surface, and 2.81 ± 0.02 mm and 3.02 ± 0.02 mm on the buccal surface.
CONCLUSIONS
It was possible to obtain 3 mm or more thickness on the labial and buccal sides with a single sheet by adjusting the sheet extrusion direction and the heating method of the sheet, and by applying the thermoforming method where the model is moved forward just before formation.
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