Effect of impact direction on the cushion property of mouthguards: a finite element analysis
Zhu, Y.-B.; Lai, G.-Y.; Wang, J.
Shanghai Kou Qiang Yi Xue 27(6): 574-578
2018
ISSN/ISBN: 1006-7248 PMID: 30899935 Document Number: 697382
The aim of this study was to evaluate the cushion property of mouthguards when the impact object came from different directions. A 3D finite element model of upper central incisor, periodontal ligament and alveolar bone was developed based on cone-beam CT (CBCT) images of a plastic teeth model. The mouthguards were modeled in 5 different thickness (T: 0, 1.5, 3, 4.5 and 6 mm) and a nonlinear dynamic impact analysis, in which the finite element models were collided by a steel ball from different directions (D: angles between the impact direction and the long axis of tooth were 30°, 60°, 90°, 120°, respectively), was performed. The stress cushion efficiency was calculated. The stress cushion efficiency of the mouthguards varied with different thicknesses and impact directions. When T=1.5 mm and 3 mm, the stress cushion efficiency was minimal as D=60° and maximal as D=120°. However, when T=4.5 mm and 6 mm, the stress cushion efficiency was minimal as D=90° and maximal as D=30°. Moreover, the stress cushion efficiency of mouthguards improved with the increasing thickness in each impact direction. The impact direction affects the stress cushion efficiency of mouthguards, which however is influenced by the thickness of mouthguards.