Fabrication of Shock Absorbing Photopolymer Composite Material for 3D Printing Sports Mouthguard

Abstract

Sports mouthguards (MGs) can reduce the risks of sports-related oral injuries. The aim of this study was to fabricate a composite photopolymer with shock-absorbing properties suitable for use in 3D-printed MGs. By using a commercial, flexible, rubber-like photopolymer as matrix and a commercial rigid simulated polypropylene photopolymer as a reinforcement material, five composites with different Shore A hardness levels were fabricated. Furthermore, four laminated materials were prepared to assess the improvement effects associated with adding a rigid outer layer. The five composites and four laminated materials were evaluated in terms of their shock absorbing capabilities via a steel ball drop impact test along with two types of conventional mouthguard materials. The rubber-like photopolymer composite material compounded with the rigid photopolymer with a Shore A hardness of 50 showed excellent shock absorbing capabilities that were compatible with conventional mouthguard materials, suggesting that this shock absorbing photopolymer composite is a candidate material for 3D-printed sports MGs. If the commercial flexible rubber-like photopolymer is to be applied alone without reinforcement, laminating a rigid photopolymer on the outer surface may be an effective means of improving the shock absorption capabilities of such a MG. We succeeded in fabricating a prototype of a doublelayered mouthguard with these composite materials using a 3D digital dental workflow.

Air Permeability, Shock Absorption Ability, and Flexural Strength of 3D-Printed Perforated ABS Polymer Sheets with 3D-Knitted Fabric Cushioning for Sports Face Guard Applications

“…Fixed prostheses and indirect dental restorations can now be fabricated from different materials using computer-aided design and computer-aided manufacturing technologies [ 22 ]. In addition, the shock absorption abilities of photopolymer composite materials suitable for use in 3D-printed sports mouthguards have been examined recently, and mouthguards have been fabricated successfully from these materials [ 23 ]. Digital technology reduces the number of clinical and laboratory steps, leading to fast and effective delivery of the final custom-made medical device [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ].…”

Effect of Vinyl Acetate, Glass Fibers Contents, and Buffer Space on EVA's Mechanical Property and Shock Absorption Ability

“…However, the high cost of this material should be addressed in future studies, and its safety for the human body should be explored. Regarding the application of 3D printing technology, [37][38][39] software issues, material development, adhesion, and accuracy should be considered. Moreover, deformation because of occlusal force, measurement, and changes in retention force should be analyzed.…”

“…Thus, the manufactured EVA materials can be thermoformed. [37][38][39] EVA hardness can be adjusted by varying the amount of VA in the EVA material. Through the hardness, strength, and impact resistance improvement because of the addition of fibers to EVA, it would be possible to produce MGs with the necessary characteristics depending on the different MG parts.…”

Disinfection and Isotonic Drinks’ Influence on Hardness and Color Stability of Ethylene-Vinyl-Acetate Copolymer Mouthguards Used in Martial Arts: An In Vitro Study

“…Currently, new methods for mouthguard fabrication are being introduced-the use of digital techniques could perhaps allow one to 3D print a new appliance without the need for another impression, opening the possibility for more frequent replacement. Of course, the new methods and materials used will require thorough testing, but preliminary reports are promising [72][73][74]. Li Z et al [72] published preliminary results evaluating the use of CAD/CAM methods in the design of protective splints from PEEK, indicating that such mouthguards had favorable clinical properties.…”