EVA mouthguards: how thick should they be?

Abstract

A major consideration in the performance of mouthguards is their ability to absorb energy and reduce transmitted forces when impacted. This is especially important to participants in contact sports such as hockey or football. The thickness of mouthguard materials is directly related to energy absorption and inversely related to transmitted forces when impacted. However, wearer comfort is also an important factor in their use. Thicker mouthguards are not user-friendly. While thickness of material over incisal edges and cusps of teeth is critical, just how thick should a mouthguard be and especially in these two areas? Transmitted forces through different thicknesses of the most commonly used mouthguard material, ethylene vinyl acetate (EVA) (Shore A Hardness of 80) were compared when impacted with identical forces which were capable of damaging the oro-facial complex. The constant impact force used in the tests was produced by a pendulum and had an energy of 4.4 joules and a velocity of 3 meters per second. Improvements in energy absorption and reductions in transmitted forces were observed with increasing thickness. However, these improvements lessened when the mouthguard material thickness was greater than 4 mm. The results show that the optimal thickness for EVA mouthguard material with a Shore A Hardness of 80 is around 4 mm. Increased thickness, while improving performance marginally, results in less wearer comfort and acceptance.

Post thermoforming dimensional changes of ethylene vinyl acetate used in custom‐made mouthguards for trauma prevention – a pilot study

“…The stretching pattern for additional layers of material was not tested in the current investigation, however, the unrealistic expectation of no thinning of the second layer of material over the incisal/cuspal regions would be required to realize this goal. Increased potential for trauma must exist also where an insufficient Anterior -upper right central 1 3 mm below labial gingival margin 2 Mid point on labial aspect of tooth 3 Incisal edge 4 Mid point on lingual aspect of tooth 5 3 mm below lingual gingival margin Posterior -upper right first molar 6 3 mm below buccal gingival margin 7 The current investigation highlights a number of variables that can result in altered dimensions for thermoformed EVA used in the construction of mouthguards.…”

“…To maximize their protective effect, sufficient thickness of material must be developed over critical areas such as incisal edges of anterior teeth where risk of injury is increased (2). The research of Westerman et al (5) revealed a preference for 4 mm thickness over critical areas such as incisal edges and tooth cusps. With regard to optimum crosssectional thickness for EVA thermoformed mouthguards, Tran et al (4) advocate that appliances should be at least 4 mm thick in order to optimize their protective qualities.…”

Sports dentistry: a perspective for the future

“…MG must be individually made by a dentist, using plaster model of the athlete, as determined by ASTM 697-80 48 which also determines that MG for sports should not hamper the phonetic and breathing, not a ect the physical performance of the athlete and enable longer use the same equipment 44,[48][49] . The MG does not affect systemic functions of the athlete 44 , and acts better dissipating the stresses transmitted in the area of impact and reducing the incidence of: lacerations of soft tissue, trauma to the anterior teeth after a frontal blow, damage to the posterior teeth in both arches and mandibular fractures 44,50 . ere are di erences between researches on the use of MG related to the prevention of mild traumatic brain injury (MTBI).…”

Avaliação do conhecimento de jogadores de futebol de Nova Friburgo-RJ e Mossoró-RN sobre traumatismo dentário.

“…Vale lembrar que o acompanhamento do paciente, mesmo com o tratamento finalizado, é indispensável 6 . O uso de protetores bucais foi a solução encontrada pelos cirurgiões-dentistas para minimizar o número de lesões orofaciais decorrentes do trauma durante prá-ticas esportivas de contato 7 . No entanto, apesar de serem considerados tão vantajosos, ainda são dispositivos desconhecidos por grande parte da população, inclusive por profissionais da Odontologia e ligados ao esporte 8 .…”