Impact Absorption Power of Polyolefin Fused Filament Fabrication 3D-Printed Sports Mouthguards: In Vitro Study

Area of Science:

• Sports Dentistry
• Materials Science
• Biomechanical Engineering

Background:

• Traditional sports mouthguards are often made from thermoformed ethylene vinyl acetate (EVA).
• Evaluating advanced materials like 3D-printed polyolefins is crucial for improving protective equipment.
• Impact absorption is a key performance metric for sports mouthguards.

Purpose of the Study:

• To compare the impact absorption capacities of thermoformed EVA and 3D-printed polyolefin mouthguards.
• To determine if 3D-printed polyolefin mouthguards provide superior impact toughness for sports applications.
• To assess the influence of printing orientation on the performance of 3D-printed mouthguards.

Main Methods:

• Assessed six materials: five EVA types and one 3D-printed polyolefin.
• Utilized a modified ASTM D256 Test Method A (Izod pendulum impact resistance).
• 3D-printed polyolefin samples were fabricated using fused filament fabrication (FFF) with varying notch orientations (parallel/perpendicular to build direction).

Main Results:

• 3D-printed polyolefin mouthguards (12.9 ± 0.7 kJ/m²) showed significantly higher impact absorption than EVA mouthguards (5.4 ± 0.3 kJ/m²).
• Polyolefin samples printed with notches perpendicular to the build direction exhibited greater impact strength (p=0.009).
• One EVA material (PolyShok) demonstrated lower impact toughness compared to other EVA samples.

Conclusions:

• 3D-printed polyolefin mouthguards offer significantly better impact toughness than thermoformed EVA mouthguards.
• Build orientation in 3D printing impacts material performance, with perpendicular orientations enhancing impact absorption.
• Further research is recommended to optimize manufacturing and testing for improved mouthguard performance.