CA2661498A1 - Thermoformed dental appliance from multiple ply sheet - Google Patents

Thermoformed dental appliance from multiple ply sheet Download PDF

Info

Publication number
CA2661498A1
CA2661498A1 CA002661498A CA2661498A CA2661498A1 CA 2661498 A1 CA2661498 A1 CA 2661498A1 CA 002661498 A CA002661498 A CA 002661498A CA 2661498 A CA2661498 A CA 2661498A CA 2661498 A1 CA2661498 A1 CA 2661498A1
Authority
CA
Canada
Prior art keywords
ply
dental appliance
sheet
appliance
dental
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA002661498A
Other languages
French (fr)
Other versions
CA2661498C (en
Inventor
Dann Schwartz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dentsply Sirona Inc
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2661498A1 publication Critical patent/CA2661498A1/en
Application granted granted Critical
Publication of CA2661498C publication Critical patent/CA2661498C/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61CDENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C7/00Orthodontics, i.e. obtaining or maintaining the desired position of teeth, e.g. by straightening, evening, regulating, separating, or by correcting malocclusions
    • A61C7/08Mouthpiece-type retainers or positioners, e.g. for both the lower and upper arch

Abstract

A dental appliance comprising at least two plies of thermoformable material, wherein a first ply of a first material, having a first set of characteristic properties, provides a first primary surface of the dental appliance and wherein a second ply of a material different from the first ply, having a second set of characteristic properties, provides an opposing second primary surface of the dental appliance. Method of making such a dental appliance.

Description

THERMOFORMED DENTAL APPLIANCE
FROM MULTIPLE PLY SHEET

[00011 The present invention is generally directed to dental appliances and more particularly to thermoforrned dentai appliances.

Backpround [0002] Orthodontic and other dental laboratories provide services for the custom-fabrication of dental appliances for an individual patient according to a treatment plan and a prescription provided by an attending orthodontist or dentist. A poured and cured stone replica of a patient's mouth structure, such as an initial malocclusion for example, is typically provided by the doctor for the laboratory's use.
[0003] The dental technicians at the lab first modify the stone model by cutting the mal-positioned teeth free of the model and the adjacent teeth. Next, a technician repositions the teeth on the model semi-rigidly into desired, ideal positions as specified by the doctor and as determined by the doctor's diagnosis and subsequent treatment plan. After the stone model has been modified or "corrected" in this manner, the model will be positioned within an appliance-forming machine where a sheet of thermo-formable elastomeric material is typically "sucked-down" or pressed over the stone model(s).
[0004] The use of thin sheets of various thermo-formable plastics including vinyl and olefin-type materials has been adopted for many current appliances. This, along with an efficient forming process involving the rapid use of pressure, vacuum and heat, has replaced prior molding and casting processes. The use of these materials, including polypropylene in sheet form and in thicknesses of about 1 mm (before thermofonming), eliminates the time-consuming steps of mixing, catalyzing and curing and optionally heat-curing in a pressure flask, as was required by natural rubber, medical-grade urethane, silicone and vinyl silicone series materials.
[0005] Polypropylene (PP), for example, is often used in making dental appliances because it is non-reactive chemically and thoroughly biocompatible.
However, PP alone may exhibit plastic creep over time, resulting in minor, but undesirable changes in the appliance's shape and it may also lack the level of clarity desired by some patients. Likewise, PP's characteristics for making a dental appliance by thermoforming is adequate, but not ideal for consistent, accurate products.
This may prevent cost effective pro'duction of consistent, high-quality appliances demanded by dentists and their patients.

[00061 Better thermoforming characteristics are found in medical grade copolyester sheets, which are also used to make dental appliances. However, dental appliances made from copolyester sheets alone have a tendency to become brittle over time. As a result, a patient wearing such an appliance who has a tendency to grind his teeth may grind into or through the appliance, reducing or eliminating the appliance's effectiveness.

Summarv of the Invention [0007] It has been discovered that a multiple ply sheet of different materials can be used to manufacture a dental appliance that has the desired mechanical properties for a dental appliance while also exhibiting the type ofthermo-f.orming characteristics that permit dental appliances to be consistently produced with high quality.

[00081 According to an exemplary embodiment of the invention, a dental appliance comprises a thermoformable material having at least two plies, in which each of the two plies are of different materials. The material of the fust ply has a first set of characteristic properties and forms a first surface of the appliance and the material of the second ply has a second set of characteristic properties and forms an opposing second surface of the appliance. Each ply has two major surfaces; the first and second plies have a common interface, with one ply having a major surface facing away from the teeth and the other ply having a major surface facing toward the teeth.
[0009] According to another exernplary embodiment of the invention, a method of making a dental appliance is also provided. The method includes providing a sheet of thermoplastic material having at least two plies as described above, preferably by co-extruding, and thereafter thermoforming the sheet to form a dental appliance, 10010J One advantage of exemplary embodiments of the invention include providing a thermoformed dental appliance made from a multi-ply sheet of different materials that has better combined mechanical and thermoforming properties than a sheet of a single material.

[00111 Another advantage of certain exemplary embodiments of the invention is that the thicIatess of the multi-ply sheet used in the dental appliance is comparable with that of single ply materials used in thermoformed dental appliances.

Brief Description of the Drawino 100121 Figure 1 illustrates a dental appliance =according to one exemplary embodiment of the invention.

100131 Figure la is a cross-sectional view of the dental appliance of Figure 1.
[00141 Figure 2 illustrates a coextruded sheet for use in forming a dental appliance according to an exemplary embodiment of the invention.

Detailed Description of Exemplary Embodiments [0015] As used herein, "dental appliance" means any device capable of being formed for use in dental applications with or without additional components such as wires and includes, by way of example only, aligners, positioners, night guards, retainers, splints, bleaching trays, and anterior bridges. Figure I
illustrates an exemplary dental appliance 5. according to one embodiment of the= invention.
The appliance 5 has a first, or outer, surface 15 that, when worn, is exposed to the patient's mouth tissue, as well as any food or drink entering the patient's mouth. A
second, inner surface 25 of the dental appliance 5 that is arranged to face the surface of one or more of the patient's teeth.

[00161 The appliance 5 is formed from a multi-ply sheet 10 as shown in Figure 2.
The sheet 10 includes a first ply 100 of a first material and a second ply 200 of a second material different from the first material. The sheet 10 has a first surface I I
that is formed by a first surface 110 of the first ply 100 and an opposing second surface 12 that is formed by a first surface 210 of the second ply 200. The first surface 11 of the sheet 10 may be positioned during the dental appliance manufacturing process to form either one of the outer surface 15 or the inner surface 25 of the dental appliance 5, such;;that the sheet's opposing second surface 12 forms the opposite surface 25 of the dental appliance 5.
.l 10017) The first ply 100 in the multi-ply sheet 10 can be any thermoplastic or elastomeric material that is permanently deformable under heat or pressure and that has properties suitable for use in a dental appliance. Thermosetting materials may also be used, which, for example, may be cured during the thermoforming process.
By "permanently deformable" is meant that the materials can be formed =to a desired shape under conditions of elevated pressure and/or temperature and which will substantially retain that shape under normal conditions experienced in the mouth, but does not necessarily mean that subjecting the materials to elevated pressures and temperatures would not cause permanent deformation to a new, different shape.
Properties which are desirable for use in a dental appliance include transparency, toughness, and biocompatibility by way of example only. Copolyesters have the characteristic of providing consistently accura.te thermoformed dental appliances and may be particularly suitable materials for use as the first ply 100. Other exemplary materials for use as the first ply 100 include ethyl vinyl acetate (EVA), polypropylene (PP), polyvinylchloride (PVC), low density polyethylene (LDPE), and high density polyethylene (HDPE).

[0018] The second ply 200 in the multi-ply sheet 10 can be any thermoplastic or elastomeric material permanently deformable under heat or pressure that is a different composition from the first ply material. The second ply material should also have suitable properties for use in a dental appliance and should have a coefficient of thermal expansion comparable or equal to that of the first ply material.
Otherwise, the subsequent thermoforming process to make the dental appliance 5 may cause one ply to shrink disproportionately with respect to the other, which may result in undesirable crimping or puckering that could lead to a poor quality or unusable dental appliance.
One suitable material for the second ply 200 include copolyester ethers, although copolyesters of a composition different from the first ply material may also be used.

Other exemplary materials for use as the second ply 200 include ethyl vinyl acetate (EVA), polypropylene (PP), polyvinylchioride (PVC), low density polyethylene (LDPE), and high density polyethylene (HDPE), and may also include blends of polymeric materials, with or without a rubberizing additive.

[0019] Because certain copofyesters may have excellent thermoforming properties but less desirable mechanical characteristics, the material selected for the second ply 200 may be selected for mechanical properties to provide a multi-ply sheet 10 having a combination of desirable properties. Conversely, if the material selected for the second ply 200 has good mechanical properties, it may, but does not necessarily need to have comparably good thermoforming properties if the material for the first ply 100 is selected for that characteristic.

[00201 In the preferred embodiments in which the multiple ply sheet 10 is manufactured by coextrusion, the materials of the two plies 100, 200 should also be compatible with one another for the coextrusion operation or be capable of being made compatible through'the addition of a compatibility agent as are Irnown to those of ordinary slcill in the art.

[0021] Because the sheet 10 is multi-layered and because the plies 100, 200 may have different characteristic properties, the materials selected for each ply 100, 200 may be selected depending on whether the particular ply will primarily be in contact with the tooth surface, i.e. the ply providing the inner surface 25 of the dental appliance 5, versus the ply primarily in contact the soft tissue of mouth, i_e..the ply providing the outer surface 15 of the dental appliance 5. It will be appreciated that the different materials may be of different polymeric classes (e.g., copolyesters versus copolyester ethers) or may be of the same class, but have different compositions (e.g., copolyester A versus copolyester B).

100221 According to a presently preferred embodiment, the sheet 10 is a copolyester/copolyester ether coextruded sheet and more specifically is a coexti'uded sheet having plies of Medstar and Ecdel. "Medstar" is a trade designation for a copolyester commercially available from Eastman Chemical Co. of Kingsport, Tenn.
"Ecdel" is a trade designation for a copolymer of cyclohexane dicarboxylic acid, ethylene glycol, and cyclohexane-1,4-dimethanol that is also commercially available from Eastman Chemical.

[00231 In accordance with the presently preferred embodiment, the multi-ply sheet 10 is produced by coextrdsion, although chemical and/or mechanical bonding techniques may also be used to form the multi-ply sheet 10, such as using adhesive, surface tension, a joining element, or by imparting a surface finish, such as a dovetail, that permits one ply to capture another, by way of example only.

[0024] Techniques for coextruding sheets of two or more plies of different material is well known to those of ordinary slall in the art. In accordance with exemplary embodiments of the invention, the die(s) for use in the coextrusion process is sized and dimensioned to produce a multi-ply sheet 10 having a total thickness (before thermoforming) of about 0.25 mm to about 5 mm, more preferably less than about 1 mm and still more preferably less than about 0.875 mm. Each ply within the multi-ply sheet is typically equal in thickness, although the relative thicknesses can be varied, and may be as high as about 70% to about 90% of one and about 10% to about 30% of the other.

[0025] Referring to Figure 2, an opposing second surface 120 of the first ply is positioned to face toward an opposing second surface'220 of the second ply 200. It will be appreciated that the sheet 10 may be extruded such that the plies 100, 200 are in direct contact with one another at an interfa.ce 150. Alternatively, a binder or adhesive may be intermediate the two plies 100, 200 to chemically or mechanically enhance the plies' adherence to one another to produce a single sheet 10.

[0026] It will further be appreciated that more than two plies can be employed, although the overall sheet thickness should remain as described above. The material selected for any subsequent ply can be the same or different than the material used in any other ply, although at least one ply of a different material is typically intermediate any two plies of the same material. In some embodiments, it may even be possible to use an intermediate ply of a rnaterial, as for example, a bonding layer, that is not biocompatible but which has particularly desirable other characteristics that is sandwiched between two outer plies of materials which are biocompatible, thereby negating the bio-incompatibility of the intermediate material.

[0027] Once the multiple ply sheet 10 has been produced, it may be used in dental appliance 5 manufacture such a.s by thermoforrning it to a final shape in a manner known to those of ordinary slcill in the art. Generally, thermoforming is accomplished by subjecting the multiple ply sheet 10 to a combination of pressure, heat and/or vacuum while positioned over a stone model which results in the sheet 10 generally conforming to the shape of the model to form the dental appliance 5. Custom appliances are created by providing a model of a particular patient's mouth in which the dental appliance will be used; the stone model may be a model of the patient's actual mouth or, in the case of an aligner, for example, the stone model may be a slightly modified version of the patient's mouth created by a laboratory technician to which the actual mouth is expected to conform over time.

[0028] Because the multi-ply sheet 10 will typically have two surfaces 11, 12 with different characteristics from one another, when the sheet 10 is aligned with the stone in preparation for thermoforming, the ply to be primarily in contact with the teeth should be arranged to face the stone so that it forms the inner surface 25 of the dental appliance 5. That is, whether the first surface 11 of the multi-ply sheet 10 (i.e., the outer surface 110 of the first ply 100) corresponds to the outer surface 15 or the inner surface 25 of the dental appliance 5 depends on whether the material selected for the -first ply 100 is better suited for facing toward or away from the surface of the patient's tooth. For example, in accordance with the preferred embodiment illustrated in Figure la in which the multiple ply sheet 10 has a first ply 100 of Medstar and a second ply 200 of Ecdel, the sheet 10 is positioned and the manufacturing process is conducted so that the Medstar material (i.e., the first ply 100) forms the inner surface 25 of the dental appliance 5, while the Ecdel material (i.e., the second ply 200) fonms the outer surface 15 of the dental appliance 5.

[0029] In some cases, it may be economical to produce the multi-ply sheet 10 in dimensions larger than would ordinarily be used for making any single dental appliance 5. Thus, the multi-ply sheet 10 may be provided in large rolls or sheet form which can be cut into smaller pieces by a laboratory technician.
Alternatively, the multi-ply sheet 10 may be cut down into individual sized pieces as part of the manufacturing and packaging process for use in one or more specific models of thennoforming devices. To keep the smaller multi-ply sheets 10 from sticking together and prevent damage during handling, a protective film may be removably adhered to each surface 11, 12 of the sheet 10_ [0030] While the foregoing specification illustrates and describes exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many mddifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that. the invention will include all embodiments falling within the scope of the appended claims.

Claims (2)

1. A dental appliance comprising at least two plies of thermoformable material, wherein a first ply of a first material, having a first set of characteristic properties, provides a first primary surface of the dental appliance and wherein a second ply of a material different from the first ply, having a second set of characteristic properties, provides an opposing second primary surface of the dental appliance.
2. A method for making a dental appliance comprising the steps of providing a thermoformable multi-ply sheet, wherein a first ply of a first material in the multi-layer sheet, having a first set of characteristic properties, provides a first primary surface of the multi-ply sheet and wherein a second ply of a material different from the first material, having a second set of characteristic properties, provides an opposing second primary surface of the multi-ply sheet; and thereafter thermoforming the sheet to form a dental appliance.
CA2661498A 2006-08-23 2007-08-23 Thermoformed dental appliance from multiple ply sheet Active CA2661498C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US82327806P 2006-08-23 2006-08-23
US60/823,278 2006-08-23
PCT/US2007/018765 WO2008024482A1 (en) 2006-08-23 2007-08-23 Thermoformed dental appliance from multiple ply sheet

Publications (2)

Publication Number Publication Date
CA2661498A1 true CA2661498A1 (en) 2008-02-28
CA2661498C CA2661498C (en) 2014-07-08

Family

ID=38790691

Family Applications (1)

Application Number Title Priority Date Filing Date
CA2661498A Active CA2661498C (en) 2006-08-23 2007-08-23 Thermoformed dental appliance from multiple ply sheet

Country Status (5)

Country Link
US (1) US8905756B2 (en)
EP (1) EP2073746B1 (en)
JP (1) JP5694663B2 (en)
CA (1) CA2661498C (en)
WO (1) WO2008024482A1 (en)

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5431985B2 (en) * 2010-01-25 2014-03-05 パナソニック株式会社 Mouthpiece molding base material for dental treatment and its preforming method
WO2011156806A1 (en) 2010-06-11 2011-12-15 Karl Edison Hegyi Stents and method for dental restoration using same
US20120202171A1 (en) * 2011-02-07 2012-08-09 D Anjou Lissa T Dental appliance
US9655691B2 (en) 2012-05-14 2017-05-23 Align Technology, Inc. Multilayer dental appliances and related methods and systems
CN105431107A (en) * 2013-06-04 2016-03-23 唐纳德·弗朗茨 Dental appliance system and method of manufacture
US10555792B2 (en) 2014-01-31 2020-02-11 Align Technology, Inc. Direct fabrication of orthodontic appliances with elastics
WO2015114450A1 (en) 2014-01-31 2015-08-06 Align Technology, Inc. Orthodontic appliances with elastics
CN106413623B (en) * 2014-03-21 2020-07-03 阿莱恩技术有限公司 Segmented orthodontic appliances with elastics
WO2015193709A1 (en) 2014-06-20 2015-12-23 Align Technology, Inc. Aligners with elastic layer
WO2015193710A1 (en) 2014-06-20 2015-12-23 Align Technology, Inc. Elastic-coated orthodontic appliance
US20160120619A1 (en) * 2014-10-29 2016-05-05 Brian K. Bons Orthotic Device
JP6438787B2 (en) * 2015-02-05 2018-12-19 三井化学株式会社 Mouthpiece laminate and mouthpiece
US10874483B2 (en) * 2015-07-07 2020-12-29 Align Technology, Inc. Direct fabrication of attachment templates with adhesive
US10743964B2 (en) 2015-07-07 2020-08-18 Align Technology, Inc. Dual aligner assembly
EP3804667A1 (en) 2016-03-08 2021-04-14 Mitsui Chemicals, Inc. Mouthpiece, sheet for production of mouthpiece unit, and production method of mouthpiece
US11096764B2 (en) * 2016-10-24 2021-08-24 Gilbert ACKEL Dental tray molding kit and method for dental molding
WO2018160875A1 (en) 2017-03-02 2018-09-07 Bay Materials Llc Dental appliance with differential properties
WO2018160870A1 (en) 2017-03-02 2018-09-07 Bay Materials Llc Composite removable veneer
US10870263B2 (en) 2017-05-31 2020-12-22 Bay Materials, Llc Dual shell dental appliance and material constructions
WO2019071063A1 (en) * 2017-10-06 2019-04-11 Airway Technologies, Llc Methods for manufacturing an oral appliance
US10717208B1 (en) 2019-12-04 2020-07-21 Oxilio Ltd Methods and systems for thermoforming orthodontic aligners
US20220387151A1 (en) * 2020-10-08 2022-12-08 Waqas Wahab Orthodontic Appliances, Orthodontic Appliance Preforms And Methods Of Forming Orthodontic Appliances
WO2023081903A1 (en) * 2021-11-05 2023-05-11 Smylio Inc. Method for forming an oral appliance

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0428359A (en) * 1990-05-24 1992-01-30 Mitsubishi Petrochem Co Ltd Manufacture of mouthpiece for teeth set correction
JPH0492659A (en) * 1990-08-08 1992-03-25 Sogo Shika Iryo Kenkyusho:Kk Splint
JPH0742647U (en) * 1993-12-29 1995-08-11 竹内 正敏 Mouth guard
US5989569A (en) * 1997-06-06 1999-11-23 The Procter & Gamble Company Delivery system for a tooth whitener using a permanently deformable strip of material
US6183248B1 (en) * 1998-11-30 2001-02-06 Muhammad Chishti System and method for releasing tooth positioning appliances
US6454565B2 (en) * 2000-04-25 2002-09-24 Align Technology, Inc. Systems and methods for varying elastic modulus appliances
US6524101B1 (en) * 2000-04-25 2003-02-25 Align Technology, Inc. System and methods for varying elastic modulus appliances
US6626180B1 (en) * 2000-09-08 2003-09-30 Bite Tech, Inc. Quadruple composite performance enhancing dental appliance
US6607382B1 (en) * 2000-09-21 2003-08-19 Align Technology, Inc. Methods and systems for concurrent tooth repositioning and substance delivery
JP4601860B2 (en) * 2001-06-01 2010-12-22 株式会社クラレ Mouth guard and laminated sheet for mouth guard
GB0213584D0 (en) * 2002-06-13 2002-07-24 Mohindra N K Appliance for reducing facial aging
JPWO2004049967A1 (en) * 2002-12-02 2006-05-18 正人 植野 Dental molded body and molding method thereof
US7040897B2 (en) * 2003-05-23 2006-05-09 Ultradent Products, Inc. Thin, flexible membrane dental trays and systems and methods utilizing such trays
US7210926B2 (en) * 2003-11-10 2007-05-01 General Electric Company Formable sheets for medical applications and methods of manufacture thereof
JP4489503B2 (en) * 2004-06-02 2010-06-23 有限会社アドバンスカンパニー Mouth guard
JP4942066B2 (en) * 2004-09-16 2012-05-30 国立大学法人大阪大学 Byte splint manufacturing method
US7357637B2 (en) * 2005-03-25 2008-04-15 Snap On Smile Llc Dental appliance
US20070087300A1 (en) * 2005-07-20 2007-04-19 Willison Brian D Invisible spring aligner

Also Published As

Publication number Publication date
EP2073746B1 (en) 2016-05-04
EP2073746A1 (en) 2009-07-01
US8905756B2 (en) 2014-12-09
US20090298006A1 (en) 2009-12-03
JP5694663B2 (en) 2015-04-01
WO2008024482A1 (en) 2008-02-28
CA2661498C (en) 2014-07-08
JP2010501261A (en) 2010-01-21

Similar Documents

Publication Publication Date Title
US8905756B2 (en) Thermoformed dental appliance from multiple ply sheet
EP0900056B1 (en) Custom dental tray
US5582517A (en) Multi-laminar dental impression tray assembly
US5562449A (en) Custom dental tray
US20120135369A1 (en) Method and Impression Tray for Producing a Dental Mold
US11096764B2 (en) Dental tray molding kit and method for dental molding
US20200197133A1 (en) Lingual retainer
JP2010279708A (en) Hardenable dental article and method for manufacturing the same
US20210307877A1 (en) Lingual retainer
CN111469514A (en) Three-layer co-pressing composite membrane special for invisible correction and preparation method thereof
JP2022516378A (en) Elastic orthodontic appliances, systems, and usage
CN110811875A (en) Film for manufacturing tooth socket, tooth socket and method for manufacturing tooth socket
EP3206624B1 (en) Method of curing a dental article
CN212382754U (en) Diaphragm for manufacturing tooth socket and tooth socket
US20200197132A1 (en) Lingual retainer
JP2013188253A (en) Tray for gum protection, method for producing the same, and mouthpiece combination body
JP2004065814A (en) Orthodontic appliance and its fabricating method
US20220387151A1 (en) Orthodontic Appliances, Orthodontic Appliance Preforms And Methods Of Forming Orthodontic Appliances
EP3273901B1 (en) Methods of using hardenable dental articles
JP2012061193A (en) Thermoplastic sheet for mouth guard
US20240138957A1 (en) Beveled dental models and orthodontic appliances made therefrom
JP2005000385A (en) Mouthpiece molding material, and mouthpiece made thereof
KR20170132627A (en) Method of producing plastic dental positioning appliance
Ibrahim et al. Rapid fabrication of functional mouthguard via rapid tooling approach
WO2023277987A1 (en) Dental restoration devices and methods

Legal Events

Date Code Title Description
EEER Examination request