Effect of surface treatment of ethylene vinyl acetate on the delamination of custom‐fitted mouthguards

Abstract

Background/Aim Contamination of ethylene vinyl acetate (EVA) during mouthguard fabrication can cause delamination. The study evaluated the effects of different EVA surface treatments on the contact angle, laminate bond strength, and elongation capacity. Materials and Methods Specimens of two bonded EVA plates were prepared (n = 30). The Shore A hardness of standardized EVA plate specimens was measured before and after thermo‐plasticization. The EVA plates were randomly allocated to one of five different surface treatment groups: no treatment (control); isopropyl alcohol, 100%; chloroform, 99.8%; self‐cure acrylic resin monomer (methacrylate, ethylene glycol dimethacrylate, and chemical initiator—amine type); and ethyl alcohol, 70%. The maximum breaking force and elongation at the site of fracture were recorded using a universal testing machine. The contact angle surface was measured using ImageJ software. Scanning electron microscopy of the EVA surface was performed. The laminate bond strength was obtained by dividing the maximum breaking force by the bonding area between the two EVA plates. The laminate bond strength and maximum elongation data were analyzed by one‐way ANOVA, followed by the Tukey's and the Dunnet test. The failure mode data was analyzed using the chi‐square test (α = .05). Results EVA surface treatment significantly influenced the laminate bond strength and maximum elongation (p < .001). The control group had a higher contact angle and significantly lower laminate bond strength and maximum elongation than the other groups (p < .001). The acrylic resin monomer and chloroform‐treated specimens had similar laminate bond strength and maximum elongation. The acrylic resin monomer group had a significantly lower contact angle (p < .001). Conclusions All treatments had a significantly higher laminate bond strength and maximum elongation than the control group. The acrylic resin monomer and chloroform groups had a significantly higher laminate bond strength and maximum elongation and the acrylic resin monomer group had a lower contact angle than the other groups. The chloroform should be avoided due its hazardous effects.

Biomechanical effects of a hard insert and air space in mouthguards on the shock absorption and protection against fractures of direct resin composite veneers from trauma

“…A 3.0 mm EVA was centered in the model and formed for 20 s. The model was removed from the vacuum‐forming machine and left at room temperature to be manipulated. The excess was removed using a scalpel blade, and the EVA surfaces were cleaned using monomer acrylic resin 38 . A second EVA layer was molded over the first layer, obtaining an MTG of 4.0 mm in thickness covering all teeth and extending to the canines.…”

“…The excess was removed using a scalpel blade, and the EVA surfaces were cleaned using monomer acrylic resin. 38 A second EVA layer was molded over the first layer, obtaining an MTG of 4.0 mm in thickness covering all teeth and extending to the canines. To create the Air-MTG, a 2.0 mm thick polyvinyl siloxane impression material (Express XT, 3 M Oral Care) was positioned on the buccal face of the printed teeth.…”

Effect of different materials for conventional and 3D‐printed models on the mechanical properties of ethylene‐vinyl acetate utilized for fabricating custom‐fit mouthguards

“…2,5,9,10 Ethylene-vinyl acetate (EVA) is the most popular material utilized to manufacture custom-fit MTGs owing to its applicability as a hot-melt adhesive layer that can be easily employed with thermoforming methods to fabricate a customized device. [11][12][13] The effectiveness of MTGs is also related to the type of EVA utilized, as well as its physical and mechanical properties. 2,14,15 According to the American National Standards Institute, EVA must have low water absorption, adequate hardness, impact resistance, low incidence of delamination, and be biocompatible, nontoxic, and insipid.…”

“…2,14,15 According to the American National Standards Institute, EVA must have low water absorption, adequate hardness, impact resistance, low incidence of delamination, and be biocompatible, nontoxic, and insipid. 10,13 Dental models can be obtained using Types II, 16 III, [17][18][19] or IV, 2,20 dental stones with different curing times (minutes) and expansion hardening (mm). The dental stones can also be modified, presenting resin reinforcements in their composition, which can also interact with the thermo-plasticized EVA.…”

Pain management, pediatric dental injuries, and dental trauma education

“…Therefore, more studies on EVA surface treatment are necessary to improve the quality of the fabricated mouthguards. In this Issue , de Melo et al aimed to evaluate the effects of different surface treatment protocols on the double‐layer EVA mouthguard 13 . This study involved the characterization of the EVA surface, mechanical alteration, bonding interaction between the double‐layer EVA, and the benefits of different products applied.…”