Impact behaviour of 3D printed cellular structures for mouthguard applications

Abstract

Ethylene-Vinyl Acetate (EVA) is the most popular material for manufacturing mouthguards. However, EVA mouthguards are problematic, for example inconsistent thicknesses across the mouthguard. Additive manufacturing provides a promising solution to this problem, as it can manufacture mouthguards with a greater precision. This paper compares the energy dissipation of EVA, the current material used for mouthguards, to various designs of a 3D printed material, some of which contain air cells. Impact testing was carried out at three different strain rates. The Split-Hopkinson bar was used for medium and high strain rate tests, and an Instron test rig was used for low strain rate testing. The best performing design dissipated 25% more energy than EVA in the medium and high strain rate testing respectively while the low strain rate testing was inconclusive. This research has shown that additive manufacturing provides a viable method of manufacturing mouthguards. This opens up the opportunity for embedding electronics/sensors into additive manufactured mouthguards.

Sports mouthguard overview: Materials, fabrication techniques, existing standards, and future research needs

“…Additive SM fabrication is presently available but processes are undergoing further development. 56,87,[103][104][105][106] Additive fabrication provides the advantage of precise control of fabrication techniques, the construction of detailed internal features, which all may provide greater SM performance and retention as compared to current manufacturing methods. [104][105][106] Reported fabrication methods include fused deposition modeling, which entails a layer-by-layer technique of heated filaments placed from an extrusion head.…”

“…56,87,[103][104][105][106] Additive fabrication provides the advantage of precise control of fabrication techniques, the construction of detailed internal features, which all may provide greater SM performance and retention as compared to current manufacturing methods. [104][105][106] Reported fabrication methods include fused deposition modeling, which entails a layer-by-layer technique of heated filaments placed from an extrusion head. [104][105][106] Photopolymer jetting uses a light-curable polymer that is placed on a building platform from an inkjet-type printing head and cured layer by layer.…”

“…[104][105][106] Reported fabrication methods include fused deposition modeling, which entails a layer-by-layer technique of heated filaments placed from an extrusion head. [104][105][106] Photopolymer jetting uses a light-curable polymer that is placed on a building platform from an inkjet-type printing head and cured layer by layer. 87,106 Additive SM manufacturing materials include EVA, but thermoplastic coployesters, 104 polylactic acid, polystyrene, polymethyl methacrylate, polyurethane, and proprietary polymers materials have also been investigated.…”

“…[104][105][106] Photopolymer jetting uses a light-curable polymer that is placed on a building platform from an inkjet-type printing head and cured layer by layer. 87,106 Additive SM manufacturing materials include EVA, but thermoplastic coployesters, 104 polylactic acid, polystyrene, polymethyl methacrylate, polyurethane, and proprietary polymers materials have also been investigated. 87,[103][104][105] Furthermore, polyetherketone (PEEK) mouthguards fabricated from a subtractive method have been proposed.…”

Evaluation of Mechanical Properties of 3D-Printed Polymeric Materials for Possible Application in Mouthguards

“…al. [ 30 ] assessed the energy dissipation of 3D-printable material (Arnitel ID 2045 Natural; DSM, Heerlen, The Netherlands), showing that the printed samples dissipated 25% more energy than EVA in both a medium and high strain rate. Liang et.…”