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 MSA  Vol.10 No.4 , April 2019
Influence of Continuous Use of a Vacuum-Forming Machine for Mouthguard Thickness after Thermoforming: Effect of the Time Interval between Repeat Moldings
Abstract: Mouthguards can reduce the risk of sports-related injuries, but the sheet material and thickness have a large effect on their efficacy and safety. This study was intended to predict the changes in thickness of molded products by clarifying the effect of the time interval between repeat moldings during the continuous use of a vacuum-forming machine. Ethylene vinyl acetate mouthguard sheets were used for thermoforming with a vacuum-forming machine. The working model was trimmed to a height of 23 mm at the maxillary central incisor and 20 mm at maxillary first molar. Five molding conditions were investigated: 1) molding was carried out after the sag at the center of the softened sheet was 15 mm (control); 2) sheet heating was started 5 min after the molding of the control (AF5-Re1); 3) sheet heating started 5 min after the molding of AF5-Re1 (AF5-Re2); 4) sheet heating started 10 min after the molding of the control (AF10-Re1); and 5) sheet heating started 10 min after the molding of AF10-Re1 (AF10-Re2). Sheet thickness after fabrication was determined for the incisal edge, labial surface, cusp, and buccal surface using a special caliper accurate to 0.1 mm. Thickness differences of the molding conditions were analyzed by two-way analysis of variance. Significant differences between the control and AF5-Re1 were observed at all measurement points (p < 0.01), but not between the control and AF10-Re1. AF10-Re2 became thinner than AF10-Re1 (p < 0.01). Reproducible molding results were obtained by waiting 10 min between the first and second moldings, but the third molded mouthguard was significantly thinner, despite this 10 min wait interval.
Cite this paper: Takahashi, M. and Bando, Y. (2019) Influence of Continuous Use of a Vacuum-Forming Machine for Mouthguard Thickness after Thermoforming: Effect of the Time Interval between Repeat Moldings. Materials Sciences and Applications, 10, 293-301. doi: 10.4236/msa.2019.104022.
References

[1]   Verissimo, C., Costa, P.V., Santos-Filho, P.C., Tantbirojn, D., Versluis, A. and Soares, C.J. (2016) Custom-Fitted EVA Mouthguards: What Is the Ideal Thickness? A Dynamic Finite Element Impact Study. Dental Traumatology, 32, 95-102.
https://doi.org/10.1111/edt.12210

[2]   Gialain, I.O., Coto, N.P., Driemeier, L., Noritomi, P.Y. and Dias, R.B. (2016) A Three-Dimensional Finite Element Analysis of the Sports Mouthguard. Dental Traumatology, 32, 409-415.
https://doi.org/10.1111/edt.12265

[3]   Bochnig, M.S., Oh, M.J., Nagel, T., Ziegler, F., and Jost-Brinkmann, P.G. (2017) Comparison of the Shock Absorption Capacities of Different Mouthguards. Dental Traumatology, 33, 205-213.
https://doi.org/10.1111/edt.12324

[4]   Gawlak, D., Mańka-Malara, K., Mierzwińska-Nastalska, E., Gieleta, R., Kamiński, T. and Luniewska, M. (2017) A Comparison of Impact Force Reduction by Polymer Materials Used for Mouthguard Fabrication. Acta of Bioengineering and Biomechanics, 19, 89-95.

[5]   Tribst, J.P.M., de Oliveira, Dal Piva, A.M., Borges, A.L.S. and Bottino, M.A. (2018) Influence of Custom-Made and Stock Mouthguard Thickness on Biomechanical Response to a Simulated Impact. Dental Traumatology, 34, 429-437.
https://doi.org/10.1111/edt.12432

[6]   Takahashi, M., Satoh, Y. and Iwasaki, S. (2017) Effect of Thermal Shrinkage during Thermoforming on the Thickness of Fabricated Mouthguards: Part 2 Pressure Formation. Dental Traumatology, 33, 106-109.
https://doi.org/10.1111/edt.12291

[7]   Takahashi, M. and Bando, Y. (2018) Effect of the Anteroposterior Position of the Model on Fabricated Mouthguard Thickness: Part 2 Influence of Sheet Thickness and Material. Dental Traumatology, 34, 370-377.
https://doi.org/10.1111/edt.12423

[8]   Takahashi, M. and Bando, Y. (2018) Thermoforming Method to Effectively Maintain Mouthguard Thickness: Effect of Moving the Model Position Just before Vacuum Formation. Dental Traumatology. [Epub Ahead of Print]

[9]   Takahashi, M., Koide, K., Satoh, Y. and Iwasaki, S. (2016) Shape Change in Mouthguard Sheets during Thermoforming. Dental Traumatology, 32, 379-384.
https://doi.org/10.1111/edt.12261

[10]   Takahashi, M., Araie, Y., Satoh, Y. and Iwasaki, S. (2017) Influence of Continuous Use of a vacuum-Forming Machine for Mouthguard Thickness after Thermoforming. Dental Traumatology, 33, 288-294.
https://doi.org/10.1111/edt.12335

[11]   Takahashi, M. and Koide, K. (2016) Optimal Heating Condition of Mouthguard Sheet in Vacuum-Pressure Formation: Part 2 Olefin-Based Thermoplastic Elastomer. Dental Traumatology, 32, 90-94.
https://doi.org/10.1111/edt.12206

[12]   Takahashi, M., Koide, K. and Iwasaki, S. (2016) Thickness of Mouthguard Sheets after Vacuum-Pressure Formation: Influence of Mouthguard Sheet Material. Dental Traumatology, 32, 201-205.
https://doi.org/10.1111/edt.12231

[13]   Takahashi, M., Koide, K., Satoh, Y. and Iwasaki, S. (2016) Heating Methods for Reducing Unevenness Softening of Mouthguard Sheets in Vacuum-Pressure Formation. Dental Traumatology, 32, 316-320.
https://doi.org/10.1111/edt.12254

[14]   Takahashi, M., Koide, K., Suzuki, H. and Iwasaki. S. (2016) Optimal Heating Condition of Ethylene-Vinyl Acetate Co-Polymer Mouthguard Sheet in Vacuum-Pressure Formation. Dental Traumatology, 32, 311-315.
https://doi.org/10.1111/edt.12248

 
 
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