MSA  Vol.11 No.6 , June 2020
Mouthguard Thermoforming Method to Decrease Palatal Thickness While Maintaining Labial and Buccal Thickness
Abstract: Wearing a mouthguard reduces the risk of sports-related injuries, but a more comfortable design is required in order to increase the wearing rate. The aim of this study was to investigate a thermoforming method that decreases palatal thickness while maintaining labial and buccal thickness. Mouthguards were fabricated from an ethylene-vinyl acetate sheet (thickness: 4.0 mm) by using a vacuum forming machine. Four working models were prepared: 1) the anterior height was 25-mm and the posterior height was 20-mm (model A), 2) model A with the palate trimmed (model B), 3) heights 5 mm greater than model A (model C), and 4) model C with the palate trimmed (model D). The two forming conditions were as follows: 1) The sheet was formed when it sagged 15 mm below the level of the sheet frame at the top of the post under ordinary use (control); 2) The sheet frame at the top of the post was lowered and the sheet covered the model when it sagged by 15 mm. The rear side of the model was pushed to move the model forward 20 mm, and then the sheet was formed (MP). Differences in mouthguard thickness due to forming conditions and model forms were analyzed by two-way analysis of variance and Bonferroni’s multiple comparison tests. Difference in forming conditions was similar for all model forms; for the MP, the thickness of the incisal edge, labial surface, cusp and buccal surface were greater, and the palatal surface was thinner than the control. On the labial and buccal surface, the thickness difference due to the model form was observed only for the MP, and models A and B were thicker than models C and D. The palatal thickness tended to be thin in the models with the trimmed palate. This study suggested that the labial and buccal thickness of the mouthguard can be maintained, and the palatal thickness can be decreased by using the model with the palate trimmed with the forming method in which the model position is moved forward immediately before the vacuum formation.
Cite this paper: Takahashi, M. and Bando, Y. (2020) Mouthguard Thermoforming Method to Decrease Palatal Thickness While Maintaining Labial and Buccal Thickness. Materials Sciences and Applications, 11, 370-381. doi: 10.4236/msa.2020.116025.

[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.

[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.

[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.

[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 Bioeng Biomech, 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.

[6]   Gawlak, D., Mierzwińska-Nastalska, E., Mańka-Malara, K. and Kamiński, T. (2015) Assessment of Custom and Standard, Self-Adapted Mouthguards in Terms of Comfort and Users Subjective Impressions of Their Protective Function. Dental Traumatology, 31, 113-117.

[7]   Takeuchi, M. and Togaya, N. (2006) Effectively of Thermoforming Process for Fabricating of Intraoral Apparatus. Sunashobo, Tokyo, 21-26, 33-44, 54-55, 62-67, 81. (In Japanese)

[8]   Erkodent Dental Products. ERKODENT® Thermoforming Systems.

[9]   Dreve Dentamid. Thermoforming Technique.

[10]   Bemelmanns, P. and Pfeiffer, P. (2001) Shock Absorption Capacities of Mouthguards in Different Types and Thicknesses. International Journal of Sports Medicine, 22, 149-153.

[11]   Westerman, B., Stringfellow, P.M. and Eccleston, J.A. (2002) EVA Mouthguards: How Thick Should They Be? Dental Traumatology, 18, 24-27.

[12]   Geary, J.L. and Kinirons, M.J. (2008) Post Thermoforming Dimensional Changes of Ethylene Vinyl Acetate Used in Custom-Made Mouthguards for Trauma Prevention: A Pilot Study. Dental Traumatology, 24, 350-355.

[13]   Maeda, M., Takeda, T., Nakajima, K., Shibusawa, M., Kurokawa, K., Shimada, A., et al. (2008) In Search of Necessary Mouthguard Thickness: Part 1 from the View Point of Shock Absorption Ability. The Journal of Japan Prosthodontic Society, 52, 211-219.

[14]   Del Rossi, G. and Leyte-Vidal, M.A. (2007) Fabricating a Better Mouthguard: Part I Factors Influencing Mouthguard Thinning. Dental Traumatology, 23, 149-154.

[15]   Takahashi, M., Koide, K., Satoh, Y. and Iwasaki, S. (2016) Shape Change in Mouthguard Sheets during Thermoforming. Dental Traumatology, 32, 379-384.

[16]   Farrington, T., Coward, T., Onambele-Pearson, G., Taylor, R.L., Earl, P. and Winwood, K. (2016) An Investigation into the Relationship between Thickness Variations and Manufacturing Techniques of Mouthguards. Dental Traumatology, 32, 14-21.

[17]   Takahashi, M., Araie, Y., Satoh, Y. and Iwasaki, S. (2017) Shape Change in Mouthguard Sheets during Thermoforming: Part 2 Effect of the Anteroposterior Position of the Model on Fabricated Mouthguard Thickness. Dental Traumatology, 33, 114-120.

[18]   Parker, K., Marlow, B., Patel, N. and Gill, D.S. (2017) A Review of Mouthguards: Effectiveness, Types, Characteristics and Indications for Use. British Dental Journal, 222, 629-633.

[19]   Mizuhashi, F., Koide, K., Takahashi, M. and Mizuhashi, R. (2012) A Method to Maintain the Thickness of the Mouthguard after the Vacuum Forming Process: Changes of the Holding Conditions of the Mouthguard Sheet. Dental Traumatology, 28, 291-295.

[20]   Takahashi, M., Koide, K. and Mizuhashi, F. (2012) Difference in the Thickness of Mouthguards Fabricated from Step-Type Polyolefin-Polystyrene Copolymer Sheets Differently Arranged v-Shaped Grooves. Journal of Prosthodontic Research, 56, 281-286.

[21]   Takahashi, M., Koide, K. and Mizuhashi, F. (2015) Variation in Mouthguard Thickness Due to Different Heating Conditions during Fabrication: Part 2. Dental Traumatology, 31, 18-23.

[22]   Takahashi, M. and Koide, K. (2016) Variation in Mouthguard Thickness According to Heating Conditions during Fabrication: Part 2 Sheet Shape and Effect of Thermal Shrinkage. Dental Traumatology, 32, 185-191.

[23]   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.

[24]   Gómez-Gimeno, à., Zamora-Olave, C., Cordobés-Navarro, M., Willaert, E. and Martinez-Gomis, J. (2019) Satisfaction with Shortening the Palatal Extension of a Mouthguard for Water Polo Players: A Randomized Crossover Study. Dental Traumatology, 35, 135-141.

[25]   Takahashi, M. and Bando, Y. (2019) Thermoforming Technique for Maintaining the Thickness of Single-Layer Mouthguard during Pressure Formation. Dental Traumatology, 35, 285-290.

[26]   Ilia, E., Metcalfe, K. and Heffernan, M. (2014) Prevalence of Dental Trauma and Use of Mouthguards in Rugby Union Players. Australian Dental Journal, 59, 473-481.

[27]   Bergman, L., Milardovic, Ortolan. S., Zarkovic, D., Viskic, J., Jokic, D. and Mehulic, K. (2017) Prevalence of Dental Trauma and Use of Mouthguards in Professional Handball Players. Dental Traumatology, 33, 199-204.

[28]   Afrashtehfar, K.I. and Chung, J. (2017) Mouthguard Use May Reduce Dentofacial Injuries in Field Hockey Players. Evidence-Based Dentistry, 18, 48-49.

[29]   Yamada, J., Maeda, Y., Satoh, H. and Miura, J. (2006) Anterior Palatal Mouthguard Margin Location and Its Effect on Shock-Absorbing Capability. Dental Traumatology, 22, 139-144.

[30]   Maeda, Y., Machi, H. and Tsugawa, T. (2006) Influences of Palatal Side Design and Finishing on the Wearability and Retention of Mouthguards. British Journal of Sports Medicine, 40, 1006-1008.

[31]   Gebauer, D.P., Williamson, R.A., Wallman, K.E. and Dawson, B.T. (2011) The Effect of Mouthguard Design on Respiratory Function in Athletes. Clinical Journal of Sport Medicine, 21, 95-100.

[32]   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.

[33]   Takahashi, M. and Bando, Y. (2019) Thermoforming Method to Effectively Maintain Mouthguard Thickness: Effect of Moving the Model Position Just before Vacuum Formation. Dental Traumatology, 35, 121-127.

[34]   Takahashi, M. and Bando, Y. (2019) Movement of Model Position Just before Vacuum Forming to Ensure Mouthguard Thickness: Part 2 Effect of Model Moving Distance. Dental Traumatology, 35, 291-295.