Effect of ethylene vinyl acetate (EVA) closed cell foam on transmitted forces in mouthguard material.
OBJECTIVE
To compare transmitted forces through ethylene vinyl acetate (EVA) mouthguard material and the same EVA material with gas inclusions in the form of a closed cell foam.


METHODS
EVA mouthguard materials with and without foam gas inclusions and 4 mm thick were impacted with a constant force from an impact pendulum. Various porosity levels in the foam materials were produced by 1%, 5%, and 10% by weight foaming agent. The forces transmitted through the EVA after energy absorption by the test materials were measured with a force sensor and compared.


RESULTS
Only minor non-significant differences in transmitted forces through the EVA with and without foam were shown.


CONCLUSIONS
The inclusion of gas in the form of a closed cell foam in 4 mm thick EVA mouthguard materials did not improve the impact performance of the EVA mouthguard material.
Westerman
B
B
University of Queensland, 500 Sandgate Road, Clayfield 4001, Queensland, Australia. airgard@mgard.com.au
Stringfellow
P M
PM
Eccleston
J A
JA
Harbrow
D J
DJ
D003799:Dental Stress Analysis / Q000379:methods; D004867:Equipment Design / Q000379:methods; D019544:Equipment Failure Analysis; D008422:Materials Testing; D009064:Mouth Protectors / Q000592:standards*; D011145:Polyvinyls; D019876:Sports Equipment / Q000592:standards*; D013314:Stress, Mechanical
D011145:Polyvinyls; C016438:ethylenevinylacetate copolymer