Custom mouthguard

A custom mouthguard may be formed from a multiple layer assembly including an ethylene vinyl acetate/thermoplastic polyurethane layer, an ethylene vinyl acetate layer and an intervening impact shield and elastomeric framework. The elastomeric framework may include one or more posterior occlusal pads. The custom mouthguard may be molded to a positive mold of an individual's upper teeth and gums.

TECHNICAL FIELD

The invention relates generally to custom mouthguards and methods of manufacturing custom mouthguards.

BACKGROUND

Conventional custom mouthguards are manufactured using a dental impression or replica of an individual's teeth, in particular the individual's upper teeth. The individual is provided with a tray filled with a modeling compound, which forms a negative impression when bitten. The negative impression may then be used to form a positive mold of the individual's teeth. Custom mouthguards have been created from the negative impression by vacuum forming or heat laminating generally thin polymer layers around the positive mold,

SUMMARY

A custom mouthguard may include a multiple layer assembly including a first thermoplastic layer, a second thermoplastic layer and an intervening and/or embedded impact shield and/or elastomeric framework. The elastomeric framework may include one or more posterior occlusal pads partially or completely embedded in or disposed between the thermoplastic layers, The custom mouthguard may be molded to a positive mold of an individual's upper teeth and gums.

A method of forming a custom mouthguard may include vacuum forming a first polymer layer onto a positive mold of a dental impression, positioning a molded impact shield adjacent the first layer, and vacuum forming a second layer onto the positive mold, thereby encapsulating at least a portion of the impact shield between the first and second layers. The impact shield may include an anterior portion having an opening. After forming the customer mouthguard, the first and/or second layers may be pierced to form a throughole for attaching a strap.

An illustrative example may be found in a method of manufacturing a custom mouthguard for an individual. A positive mold of the individual's upper teeth and gums may be obtained. A first layer that includes an ethylene vinyl acetate/thermoplastic polyurethane copolymer may be molded onto the positive mold. An impact shield and framework may be disposed on the first layer and a second layer including ethylene vinyl acetate may be molded onto the positive mold, thereby encapsulating a portion of the impact shield and framework.

Another illustrative example may be found in a custom mouthguard having a tray floor, an outer labial wall and an inner lingual wall. The custom mouthguard may include a first layer having an ethylene vinyl acetate/thermoplastic copolymer, a second layer including an ethylene vinyl acetate polymer, and a rubber impact shield disposed between the first layer and the second layer. The first layer may form a substantial portion of the tray floor and the outer labial wall while the second layer may form a substantial portion of the inner lingual wall.

DETAILED DESCRIPTION

Teeth marks28extend into the outer labial wall18, the inner lingual wall20and the tray floor22.FIG. 2is a top view of the mouthguard10and shows how the teeth marks28are disposed along the tray floor22. It will be appreciated that the teeth marks28illustrated herein are stylized and are intended to generically represent the imprints made to fit an individual's teeth.

In some embodiments, the impact shield24includes structure that extends from the impact shield24towards the posterior side14of the mouthguard10,FIG. 3is a bottom view of the mouthguard10, showing how the impact shield24includes a framework30that includes one or more posterior occlusal pads32. Like the anterior portion of the impact shield24, the framework is at least partially embedded in the U-shaped tray16. In some embodiments, the posterior occlusal pads32include one or more solid pads34and one or more open pads36, as illustrated. It will be appreciated that the configuration of the framework30and the posterior occlusal pads32may be altered to provide desired jaw protection and alignment.

FIG. 4is a schematic illustration of how the mouthguard10may be manufactured by vacuum forming or heat lamination methods. A positive mold38is positioned on a work surface of a vacuum forming apparatus (not shown). A first layer40is then evenly heated and vacuum formed or heat laminated around the positive mold. The first layer is then optionally trimmed before or after applying an optional layer of adhesive. The pre-formed molded impact brace42is then positioned adjacent to the first layer40on the optional adhesive, and a second layer44is then evenly heated and placed over the first layer40and impact shield42such that the application of a vacuum or heat lamination causes at least portions of the impact shield42to be encapsulated within the first and second layers. Any excess layer material from the second layer44is then optionally trimmed from the mouthguard, and a hole may be formed in the second layer44at the point where the retention strap is optionally attached. Although this process is described sequentially, in one embodiment the first layer40, impact shield42and second layer44are vacuum formed substantially simultaneously.

Each of the layers may be formed of distinct materials that provide the resulting mouthguard10with desired properties and performance. In some embodiments, the first layer40may form a substantial portion of the tray floor22as well as an inner surface of the outer labial wall18. As such, the first layer40may provide a substantial amount of impact protection to the wearer's teeth. The first layer40may be formed of any suitable material that provides a desired level of impact resistance, Illustrative but non-limiting examples of suitable materials include blends of EVA (ethylene vinyl acetate) and TPU (thermoplastic polyurethane), In some embodiments, the first layer40is formed from an EVA/TPU available commercially under the CORESHOCK® tradename.

In one embodiment, the impact shield42is a molded part formed from a polymer that provides a desired blend of strength and impact energy dissipation. In some embodiments, the shield42is formed of a composite of a copolymer of ethylene and vinyl acetate and an elastomeric material such as thermoplastic rubber or vulcanized rubber. An example of a suitable copolymer of ethylene and vinyl acetate is ELVAX® resin marketed by the OP Division of Ashland Chemical Co, such as ELVAX® 350 through ELVAX® 450. In one embodiment, ELVAX® 450 is used, which has 18% by weight vinyl acetate. In some embodiments, the impact shield42includes 50% to 80% by weight of the elastomeric material and 20% to 50% by weight of the copolymer of ethylene and vinyl acetate.

In some embodiments, the elastomeric material is a thermoplastic rubber available commercially under the KRATON® tradename, from GLS Plastics of 740B Industrial Drive, Cary, Ill. 60013. This thermoplastic rubber is unique in that it is injection moldable, FDA approved and readily adheres with copolymers of ethylene and vinyl acetate,

In some embodiments, the second layer44may form a substantial portion of the inner lingual wall20. The second layer44may be formed of any suitable material. In some cases, the second44may be formed of a clear material. In some embodiments, the second layer44may be formed of a copolymer of ethylene and vinyl acetate, such as EVA. In one embodiment, the second layer44may be formed from a material that softens when contacted with boiling water such that a user can further augment the dental impression formed in the mouthguard tray.

FIG. 5is a flow diagram showing an illustrative method for forming the custom mouthguard10. A positive mold of an individual's teeth, or at least their upper teeth, is obtained as generally shown at block50. At block52, a layer including a copolymer of ethylene vinyl acetate and thermoplastic polyurethane is molded onto the positive mold. A layer including a clear polymer such as EVA is disposed above the EVA/TPU layer with an impact shield disposed between the two layers, as generally shown at block54. At block56, the layer of EVA is molded onto the EVA/TPU layer, thereby encapsulating the impact shield. Optionally, as shown in block58, the layers may be trimmed and/or a hole may be formed in the EVA layer to connect the retention strap26.