Methods of Using Hardenable Dental Articles

Abstract

A method of using a hardenable dental article is provided. [Solution] The method may include positioning a film (30) on a dental structure (40) to cover at least a portion of the dental structure (40), preparing a hardenable dental article (10), and applying the hardenable dental article (10) to the dental structure (40) covered with the film (30).

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to methods of using hardenable dental articles. [Background technology]

[0002] Hardenable dental articles, including those with malleable and therefore customizable hardenable dental compositions, are widely used in restorative dentistry. For example, tooth restoration using temporary and permanent dental articles, such as preformed crowns or bridges, is a common procedure, where the restoration process is facilitated by using dental articles preformed to the approximate shape of the tooth or teeth to be restored. When customized dental articles are desired, conventional techniques, such as preformed temporary crowns made of metal or polymer, and preformed permanent crowns made of ceramic or porcelain / metal, often require multiple dental visits.

[0003] Hardening of hardenable dental articles can result in shrinkage in the range of 1% to 2% or more, which can lead to problems such as microleakage or fracture of the hardened hardenable dental article, or an overly tight fit of the hardened hardenable dental article to the prepared tooth. Summary of the Invention

[0004] Some aspects of the present disclosure provide a method that can include positioning a film having a modulus of elasticity less than 900 MPa on a dental structure to cover at least a portion of the dental structure, providing a hardenable dental article comprising a hardenable dental composition and including a base and an inner surface extending from the base, and applying the hardenable dental article to the film-covered dental structure.

[0005] Some aspects of the present disclosure provide methods that can include providing a hardenable dental article comprising a hardenable dental composition, the hardenable dental article including a base and an inner surface extending from the base, disposing a film having a modulus of elasticity less than 900 MPa between the hardenable dental article and a dental structure, and applying the hardenable dental article to the dental structure, wherein the film contacts at least a portion of the inner surface of the hardenable dental article.

[0006] Some embodiments of the present disclosure provide a kit-of-parts that can include an undeformed film having a modulus of elasticity of less than 900 MPa and a hardenable dental article comprising a hardenable dental composition, wherein the undeformed film is separate from the hardenable dental article.

[0007] Other features and aspects of the present disclosure will become apparent by consideration of the detailed description.

[0008] Definition of Terms The term "dental article" includes, for example, temporary, intermediate, and permanent crowns, bridges, implants, artificial teeth, inlays, onlays, veneers, temporary restorations, implant healing caps, dental splints, implant abutments, copings, posts, bridge frameworks and other bridge structures, and abutments.

[0009] The term "dental structure" includes, but is not limited to, teeth, including formed teeth, artificial teeth, typodonts or other models (e.g., dental casts, stone or wax models, and 3D printed models), implants, implant healing caps, and implant abutments.

[0010] The term "malleable" refers to an article, such as a hardenable dental article, that can be custom shaped and fitted with moderate hand force (i.e., forces ranging from light finger pressure to that applied by manual manipulation of a small hand tool such as a dental composite appliance) at a temperature of 15°C to 40°C. Shaping, fitting, forming, etc. can be performed by adjusting the exterior shape and / or interior cavity shape of the hardenable dental article without adding or removing material other than at or adjacent the margins. In one example, the hardenable dental article can be fitted over a prepared tooth.

[0011] The term "curable" refers to polymerizable and / or crosslinkable.

[0012] The term "free-standing," as used herein, refers to an article, e.g., a hardenable dental article, that is dimensionally stable (will maintain its shape without significant deformation) when freestanding (i.e., without the support of a package or container) for at least about two weeks at room temperature (i.e., about 20°C to about 25°C). This definition applies in the absence of any initiator system activation conditions and in the absence of external forces other than gravity.

[0013] The term "preformed" refers to an article, e.g., a hardenable dental article, that has been formed into a shape suitable for use with or without customization, for example, for any one particular application.

[0014] The term "substantially the same" refers to a difference of no more than 20%, preferably no more than 10%, and more preferably no more than 5%, in typical embodiments of the present disclosure.

[0015] The terms "comprising" and variations thereof (e.g., comprise, include, etc.) do not have a limiting meaning where these terms appear in the description and claims.

[0016] Modulus of elasticity is a number that measures the resistance of an object or substance to being elastically deformed (i.e., non-permanent) when a force is applied to the object or substance. The modulus of elasticity of an object is defined as the slope of its stress-strain curve in the region of elastic deformation, i.e., the harder the material, the higher the modulus of elasticity. Modulus of elasticity is:

number

[0017] The yield (yield force) of a material is defined as the stress at which the material begins to deform plastically. Prior to yielding, the material will deform elastically and will recover to its original shape when the applied stress is removed. Once yielding is passed, some of the deformation becomes permanent and irreversible.

[0018] As used herein, "a," "an," "the," "at least one," and "one or more" are used interchangeably unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally utilized in its sense including "and / or" unless the content clearly dictates otherwise.

[0019] Unless otherwise specified, all numbers expressing characteristic sizes, quantities, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and appended claims are approximations that may vary depending upon the desired properties targeted by one of ordinary skill in the art using the teachings disclosed herein.

[0020] Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 2 is a cross-sectional view along the buccal-lingual direction of an embodiment of a dental article of the present disclosure. [Figure 2] FIG. 1 is a cross-sectional view of a film-covered dental structure along the buccal-lingual direction, according to one embodiment. [Figure 3] FIG. 2 is a cross-sectional view of a dental article after positioning on a film-covered dental structure along the buccal-lingual direction, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Before any embodiment of the present disclosure is described in detail, it is understood that the invention is not limited in its application to the details of use, structure, and arrangement of components set forth in the following description. The invention is capable of other embodiments and of being practiced or carried out in various ways that will become apparent to those skilled in the art upon reading this disclosure. It is also understood that the terminology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the words "including," "comprising," or "having," and variations thereof, are meant to encompass the elements listed thereafter and equivalents thereof, as well as additional elements. It is understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure.

[0023] Shrinkage is a common problem with hardened dental composites used in hardenable dental articles. For example, shrinkage can cause microfractures in the hardened dental article, which can lead to microleakage of the hardened dental article. When the hardenable dental article is a crown, shrinkage can also cause the hardened crown to fit too tightly on the prepared tooth, or the hardened crown may not seat down completely on the prepared tooth. This can lead to, for example, a poor marginal fit on the prepared tooth, as well as larger marginal gaps and / or an excessively high occlusal surface. Any undercuts that may be present on the prepared tooth can be particularly problematic. For example, lockage from the undercuts can cause potential fractures of the hardened crown and / or tooth. Both of these consequences can require additional time and effort from the dentist, either in terms of additional adjustments to the restoration when it is positioned, or potentially repairing or replacing it at a later appointment.

[0024] The present disclosure generally relates to methods of using hardenable dental articles. Generally, the hardenable dental article may include a base and at least one inner surface extending from the base. In certain embodiments, a film may be provided to cover at least a portion of a dental structure. Specifically, the film may accommodate shrinkage of the hardenable dental article. In addition, the film may have a lubricating effect, facilitating removal of the unhardened / hardened hardenable dental article and positioning (and repositioning) the unhardened / hardened hardenable dental article on a dental structure. Furthermore, the films used in the present disclosure may be removed without substantial delamination from the inner surface of the hardenable dental article or from a substantial portion of the film remaining on the dental structure, thereby providing a better fit to the dental structure. When the hardenable dental article is a crown, the film may provide a uniform gap / space between the hardened crown and the prepared tooth after removal of the film from the prepared tooth. As a result, the crown may be perfectly adapted to the prepared tooth, thereby providing a better marginal fit and correct occlusal height. Additionally, the film can provide a barrier against, for example, saliva, blood, and other fluids that may be present and / or occur during the restorative procedure, thereby protecting the tooth to be restored, or similarly multiple teeth, to the surrounding tissues of the oral cavity, i.e., gum tissue and adjacent teeth, preventing, for example, blood or saliva from reaching the tooth to be restored and keeping the area to be restored clean.

[0025] In certain embodiments, the hardenable dental articles described herein may be crowns, inlays, onlays, bridges, veneers, maxillofacial prostheses, artificial teeth, and dental splints. In certain of these embodiments, the hardenable dental article may be a crown. In some embodiments, the hardenable dental article may be a preformed hardenable dental article.

[0026] 1, one embodiment of a hardenable dental article 10 for use in the methods described herein is illustrated in cross-section. The hardenable dental article 10, which is in the shape of a crown and includes a hardenable dental composition 11, typically has an internal cavity 50 with a base 14, an outer surface 12, and an inner surface 52 extending from the base 14. The shape of the internal cavity may be a cylindrical cavity.

[0027] hardenable dental composition The hardenable dental articles described herein include a hardenable dental composition. In certain embodiments, the composition can be malleable at temperatures between 15° C. and 40° C. In certain of these embodiments, the hardenable dental composition can be malleable at temperatures ranging from room temperature to 38° C.

[0028] Examples of some potentially suitable hardenable dental compositions that have sufficient malleability and that may be used to construct the hardenable dental articles described herein include, for example, hardenable organic compositions (filled or unfilled), polymerizable dental waxes, hardenable dental compositions that have a wax-like or clay-like consistency in the unhardened state, etc. In some embodiments, the hardenable dental article is comprised of a hardenable composition that consists essentially of a non-metallic composition.

[0029] Suitable hardenable dental compositions that can be used to prepare the hardenable dental articles described herein include, for example, those described in U.S. Patent Application Publication No. 2003 / 0114553, entitled "HARDENABLE SELF-SUPPORTING STRUCTURES AND METHODS" (Karim et al.). Other suitable hardenable compositions include those described in WO 2010 / 057144 (Jones et al.), U.S. Patent Nos. 5,403,188 (Oxman et al.), 6,057,383 (Volkel et al.), 6,799,969 (Sun et al.), 7,816,423 (Karim et al.), and 8,906,981 (Yang et al.).

[0030] The organogelators described in International Publication No. 2008 / 033911, entitled "DENTAL COMPOSITIONS INCLUDING ORGANOGELATORS, PRODUCTS, AND METHODS," can be included in the hardenable dental compositions in the dental articles described herein. These organogelator compositions may be packageable or self-supporting.

[0031] In certain embodiments, the hardenable dental composition of any one of the embodiments described herein can be a photopolymerizable composite including a resin system, a filler system, and an initiator system, where the photopolymerizable composite is self-supporting and malleable. The resin system can include one or more hardenable organic resins suitable for use in the oral environment that can form a hardened composition having sufficient strength.

[0032] In some such embodiments, at least some of the resin components can contain ethylenic unsaturation and can undergo additional polymerization. In some embodiments, suitable resins can contain at least one ethylenically unsaturated monomer (i.e., contain at least one carbon-carbon double bond). Suitable resin systems include those described in U.S. Patent Nos. 7,816,423 (Karim et al.) and 8,906,981 (Yang et al.).

[0033] In some such embodiments, the resin system can include a crystalline component to impart a three-dimensional structure (e.g., non-covalent bonds) to maintain an initial preformed shape, as described in WO 2010 / 057144 (Jones et al.), U.S. Pat. Nos. 7,674,850 (Karim et al.), 7,816,423 (Karim et al.), and 8,906,981 (Yang et al.), which are incorporated herein by reference. The crystalline component may or may not have reactive groups capable of polymerization (including crosslinking). In some embodiments, the crystalline component may be polymerizable. In some embodiments, the crystalline component may be a polymer (including an oligomer). In some embodiments, the crystalline component may be a polymerizable polymeric material.

[0034] Fillers for use in the filler system may be selected from a wide range of conventional fillers for incorporation into resin systems. In some embodiments, the filler system includes one or more conventional materials suitable for incorporation into compositions used in medical applications, such as fillers currently used in dental restorative compositions. Fillers may be either particulate or fibrous in nature. Fillers may also be inorganic materials. Fillers may also be crosslinked organic materials that are insoluble in resin and optionally filled with inorganic fillers. Suitable fillers include those described in U.S. Patent Nos. 7,816,423 (Karim et al.) and 8,906,981 (Yang et al.).

[0035] The initiators for use in the initiator system, i.e., a single initiator or a mixture of two or more initiators suitable for curing (e.g., polymerizing and / or crosslinking) the resin system, may be free-radical initiators that can be activated by various methods, such as heat and / or radiation. Thus, for example, the initiator system may be a thermal initiator system (e.g., azo compounds and peroxides) or a photoinitiator system. In some embodiments, the initiator system includes one or more photoinitiators. In some such embodiments, the initiator system includes at least one photoinitiator that is active in the spectral region of about 300 nanometers (nm) to about 1200 nm and is capable of promoting free-radical polymerization and / or crosslinking of ethylenically unsaturated moieties upon exposure to light of a suitable wavelength and intensity. A wide variety of such photoinitiators may be used. Suitable initiator systems include those described in U.S. Pat. Nos. 7,816,423 (Karim et al.) and 8,906,981 (Yang et al.).

[0036] film The film used in the present disclosure may be a hydrocarbon film, such as a paraffin film. The film used in the present disclosure may be a fluoropolymer film, such as a polytetrafluoroethylene (PTFE) film. In certain embodiments, the film may be a monolayer film. In certain embodiments, the film may be a monolayer polymer film. Suitable polymers include polyurethane, polytetrafluoroethylene (PTFE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polyethylene-vinyl acetate (EVA) copolymer, and the like.

[0037] In some embodiments, the film may be a multilayer polymer film. Suitable multilayer polymer films include those described in WO 2010 / 057144 (Jones et al.). In some embodiments, the multilayer polymer film may comprise at least two different polymers in separate layers. For example, the outer layer may comprise at least one polymer, and the inner core layer may comprise at least one polymer that is different from the at least one polymer comprising the outer layer. In certain embodiments, including any one of the method embodiments described herein, the different polymers differ from each other in a property selected from the group consisting of composition, crystallinity, modulus, maximum elongation, strain recovery, recovery load, surface energy, optical properties, and combinations thereof. Examples of polymers with different compositions include, but are not limited to, elastic and plastic polymers, homopolymers and copolymers, polymers of different molecular weights, polymers of different densities, one type of polymer and another type of polymer, e.g., polyethylene and styrene-isoprene-styrene block copolymer, different molecular architectures (e.g., linear vs. branched), different amounts of polymer, different phase morphologies, etc. Differences in crystallinity can result from differences in comonomer content, differences in branching, differences in molecular weight, etc. Differences in crystallinity may translate to different elongation, modulus, density, and / or recovery properties in the separate layers. Differences in surface energy can result in good release from the hardenable dental article. Optical properties include transparency, opacity, percent haze, surface gloss, color, etc.

[0038] In some embodiments, the multilayer polymeric films used in the present disclosure can include at least two layers, including a first outer layer and a second core layer. Each of these layers can consist of one, two, or more layers. In other embodiments, the multilayer polymeric films can include at least three layers, including a first outer layer, a second core layer, and a third outer layer. Each of these layers can consist of one, two, or more layers. In certain of these embodiments, the first outer layer and the third outer layer can be subjected to substantially the same recovery load. Having substantially the same recovery load on each major surface of the multilayer film reduces or eliminates any bowing or other defects in the film caused by unequal recovery loads after strain, such as linear, biaxial, or radial extension. The outer layers, also known as skin layers, can be balanced even if the skin layers are made of different materials, different combinations of materials, and / or different thicknesses.

[0039] In some embodiments, including any one of the above embodiments, including at least one outer layer, suitable outer layers can include thermoplastic polymers described in WO 2010 / 057144, including, but not limited to, high-density polyethylene, low-density polyethylene, very-low-density polyethylene, polypropylene, poly(ethylene-co-propylene), poly(ethylene-co-hexene), poly(ethylene-co-octene), poly(ethylene-co-butene), poly(ethylene-co-vinyl acetate), poly(ethylene-co-vinyl alcohol), polyurethane, and combinations thereof. In certain of these embodiments, the thermoplastic polymer can be selected from the group consisting of isotactic polypropylene, poly(ethylene-co-propylene) impact copolymer, high-density polyethylene, and combinations thereof. These combinations include copolymers and / or blends. In certain of these embodiments, the thermoplastic polymer can be high-density polyethylene.

[0040] In some embodiments including a second core layer within a multilayer polymer film, the second core layer can comprise, but is not limited to, an elastic material, a plastic material, or a combination thereof. In certain of these embodiments, the second core layer can comprise, but is not limited to, a polymer selected from the group consisting of linear low-density polyethylene, very low-density polyethylene, styrene-isoprene-styrene block copolymer, styrene-ethylene-co-butylene-styrene block copolymer, elastomeric polyurethane, poly(ethylene-co-vinyl acetate), ethylene-propylene elastomeric copolymer, ethylene-propylene-diene elastomeric terpolymer, poly(ethylene-co-hexane), poly(ethylene-co-octene), poly(ethylene-co-butane), and combinations thereof. In certain of these embodiments, the second core layer can comprise, but is not limited to, a polymer selected from the group consisting of very low-density polyethylene, very low-density polyethylene, styrene-isoprene-styrene block copolymer, styrene-ethylene-co-butylene-styrene block copolymer, and combinations thereof. These combinations include copolymers and / or blends. In certain of these embodiments, the second core layer may include very low density polyethylene.

[0041] In some embodiments, the film may have a modulus of elasticity of less than about 900 MPa. In certain of these embodiments, the film may have a modulus of elasticity of less than 600 MPa. In certain of these embodiments, the film may have a modulus of elasticity of less than 300 MPa. The modulus of elasticity of a film generally relates to the film's ability to conform to a dental structure. If the film's modulus is greater than 900 MPa, the film will be too hard / rigid and will not conform to the dental structure, thereby preventing the hardenable dental article from conforming to the margins of the dental structure upon positioning. As a result, the finished dental article will fit poorly on the dental structure.

[0042] In some embodiments, the film may have a breaking elongation of less than 900%. In certain of these embodiments, the film may have a breaking elongation of less than 350%. If the breaking elongation of the film is greater than 900%, the film will recover from the stretched state when released after being stretched. As a result, the film will not deform when placed on a dental structure and will have poor adhesion to the dental structure.

[0043] In some embodiments, the film may have an elastic recovery after 100% strain of less than 95%. In certain of these embodiments, the film may have an elastic recovery after 100% strain of less than 60%. In certain of these embodiments, the film may have an elastic recovery after 100% strain of less than 20%. If the film has an elastic recovery after 100% strain of greater than 95%, the film will recover from the stretched state when released after being stretched. As a result, the film will not deform when placed on a dental structure and will adhere poorly to the dental structure.

[0044] In some embodiments, the film may have an Index E100 of less than 9. Index E100 is determined by multiplying the elongation at break by the elastic recovery after 100% strain. In certain of these embodiments, the film may have an Index E100 of less than 6. In certain of these embodiments, the film may have an Index E100 of less than 3. Generally, films with relatively low % elongation at break and low % elastic recovery perform better for the purposes of this disclosure. Therefore, an Index E100 of less than 3 is preferred.

[0045] In some embodiments, the film may have a thickness of 10 μm, 15 μm, 25 μm, 75 μm, 100 μm, 200 μm, or a range between any two of these values (inclusive). After removal of the film, the thickness of the film may provide a dimensional gap / space between the cured crown and the prepared tooth for bonding.

[0046] In some embodiments, the film can have a yield force of less than 30 N. In some embodiments, the film can have a non-zero yield strain.

[0047] The chemical composition of the film is not particularly limited, provided that the mechanical properties of the film are suitable for use in the method of the present disclosure.

[0048] Manufacturing method Hardenable dental articles may be prepared essentially as described in International Publication No. 2010 / 057144, U.S. Patent Nos. 7,811,486, 8,136,657, and 8,906,981, each of which is incorporated herein by reference in its entirety. The hardenable dental compositions of the present disclosure can be formed (e.g., molded) into various shapes, including, for example, three-dimensional shapes. The hardenable dental compositions can be formed by various methods, including, for example, extrusion, injection molding, compression molding, thermoforming, vacuum forming, pressing, calendaring, and web processing using rollers.

[0049] The hardenable dental article can be sold individually or in a kit of parts. The kit can include a film and a hardenable dental article of the present disclosure. In some embodiments, the film can be an undeformed film, meaning that the shape of the film remains unchanged. In certain of these embodiments, the undeformed film can be separate from the hardenable dental article.

[0050] How to use In some embodiments, the shape of the hardenable dental article used in the present methods may be in the shape of a crown, inlay, onlay, bridge, veneer, tooth facsimile, temporary crown or restoration, implant healing cap, or dental splint. In some embodiments, the shape of the hardenable dental article may be in the shape of a crown. In certain embodiments, the hardenable dental article may be a free-standing malleable hardenable crown. In the context of a free-standing malleable hardenable crown, such a crown typically has a base and an inner surface extending from the base.

[0051] In certain such embodiments, the appropriate shape and size of the self-supporting malleable crown is selected. The crown is placed on the prepared tooth, and the extent of trimming and shaping required is determined, optionally with markings on the crown (e.g., marking near the base of the crown to provide reference points along the periphery of the margins where the crown should be trimmed to better fit the prepared tooth). In some such embodiments, the crown may be optionally removed from the prepared tooth, and the required shape and size adjustments may be made (as desired) by cutting, trimming, shaping, etc. In some such embodiments, before or after trimming, a film may be stretched and positioned over the prepared tooth to cover at least a portion of the prepared tooth. In some such embodiments, the film may be centered over the prepared tooth with the long axis of the film extending in a generally buccal-lingual direction. In some such embodiments, the film may be stretched over the prepared tooth by any suitable means, such as by hand, so that the film can deform and the prepared tooth can be at least partially covered with the film. In some such embodiments, the prepared tooth can be completely covered with the film. In some such specific embodiments, the deformed film can loosely adhere to the prepared tooth. In some such specific embodiments, the deformed film, 30 in FIG. 2, can tightly conform to the prepared tooth 40. The size and shape of the film can and will vary. For example, when it is desired to restore a single tooth with a crown, a rectangular-shaped film measuring greater than about 6 cm in length by about 1.0-2.5 cm in width is typically sufficient to cover the prepared tooth. In some other specific embodiments, the size and shape of the film are large enough to cover multiple teeth to be restored. Generally, the size and shape of the film are large enough that when positioned on the dental structure, the film completely covers the dental structure and / or extends to the base of the hardenable dental article.Alternatively, in some such specific embodiments, a film may be placed between the crown and the prepared tooth before or after trimming. In some of these embodiments, the film may be in contact with at least a portion of the interior surface of the crown when the crown is positioned over the prepared tooth.

[0052] The trimmed crown, with the film placed between the preparation and the crown to be positioned, is then repositioned on the prepared tooth, where further shape customization is performed by various methods, including application of pressure with fingers or selected instruments (e.g., manual manipulation of a composite tool), trimming, cutting, carving, grinding, etc., to provide an optimal custom fit, including gingival, lateral, and occlusal fit. Figure 3 is an exemplary cross-sectional view of the crown 10 of Figure 1 after it has been positioned on a prepared tooth 40 covered with film 30. Crown shape customization can be performed inside or outside the subject's oral cavity.

[0053] Once the desired custom shape is achieved, the crown is at least partially hardened (e.g., cured) by exposing it to heat / radiation, resulting in activation of the initiator system. This can be done either in a single step or in multiple steps, with successive steps of custom shaping performed in between. In some embodiments, the reshaped crown can then be hardened, typically by exposing it to a dental curing light for a few seconds while in the oral cavity, if necessary, and then carefully removing it from the oral cavity and exposing it to a curing light, optionally in combination with heat, in a curing chamber for final curing. Alternatively, in other embodiments, the reshaped crown can be at least partially cured outside the oral cavity. In some other embodiments, the crown can also be fully cured in the oral cavity by irradiating it with a dental curing light.

[0054] In some embodiments, the film may remain in contact with at least a portion of the inner surface of the crown during the customization or curing process. In other embodiments, the film may be in contact with at least a portion of the surface of the formed tooth during the customization and / or curing process. If the film maintains contact with the inner surface of the crown during curing, this can protect the inner surface of the crown from exposure to, for example, oxygen, before and during the curing process. Additionally, the film remaining in place during curing can prevent the hardenable dental composition of the crown from undesirably adhering to the formed tooth.

[0055] After the final molding and curing process, the film can be removed from the cured crown. In some embodiments, the film can be removed as a single piece. Removing the film can provide a small, uniform gap between the cured crown and the prepared tooth to avoid, for example, an overly tight fit due to crown shrinkage or lockage due to undercutting of the prepared tooth. Furthermore, removing the film can provide the appropriate gap / gap for bonding the cured crown.

[0056] After the curing step, if desired, the cured crown may be further modified / finished by contouring, grinding, trimming, etc. Once the final custom shape of the crown is obtained, the finished crown may be polished, cleaned, painted, or surface treated if necessary for the intended application. The intended application may require mounting, bonding, or attaching the custom-shaped, cured crown to a second object adhesively, mechanically, or a combination of both. The finished crown may then be cemented in place or lined with a suitable resin composite before being positioned in the mouth.

[0057] As will be appreciated by those skilled in the art, the present methods may be applied to hardenable dental articles other than crowns, based on the teachings disclosed herein.

[0058] The following embodiments are intended to illustrate, but not limit, the present disclosure.

[0059] Embodiment Embodiment 1 is positioning a film having an elastic modulus of less than 900 MPa over the dental structure to cover at least a portion of the dental structure; providing a hardenable dental article comprising a hardenable dental composition, the hardenable dental article including a base and an interior surface extending from the base; applying the hardenable dental article to the film-covered dental structure.

[0060] Embodiment 2 is providing a hardenable dental article comprising a hardenable dental composition, the hardenable dental article including a base and an interior surface extending from the base; placing a film having a modulus of elasticity of less than 900 MPa between the hardenable dental article and the dental structure; applying the hardenable dental article to a dental structure, wherein the film contacts at least a portion of the interior surface of the hardenable dental article.

[0061] Embodiment 3 is the method of embodiment 1 or 2, further comprising customizing the shape of the hardenable dental article.

[0062] Embodiment 4 is the method of any one of embodiments 1-3, further comprising at least partially curing the hardenable dental article after the applying step.

[0063] Embodiment 5 is the method of embodiment 4, wherein the film contacts at least a portion of the interior surface during the curing step.

[0064] Embodiment 6 is the method of embodiment 4, further comprising trimming the hardenable dental article before the hardening step, after the hardening step, or both before and after the hardening step.

[0065] Embodiment 7 is the method of embodiment 4, further comprising removing the film after the curing step.

[0066] Embodiment 8 is the method of embodiment 7, wherein the inner film is removed in a single piece.

[0067] Embodiment 9 is the method of any one of embodiments 4-8, wherein the film contacts at least a portion of the surface of the dental structure during the customizing step or the curing step.

[0068] Embodiment 10 is the method of any one of embodiments 1-9, further comprising contouring and shaping the hardened dental article.

[0069] Embodiment 11 is the method of any one of embodiments 1-10, further comprising bonding the hardened dental article to a dental structure.

[0070] Embodiment 12 is the method of any one of embodiments 1-11, wherein the film has a modulus of elasticity less than 600 MPa.

[0071] Embodiment 13 is the method of any one of embodiments 1-12, wherein the film has an elongation at break of less than 900%.

[0072] Embodiment 14 is the method of embodiments 1-13, wherein the film has an elongation at break of less than 350%.

[0073] Embodiment 15 is the method of any one of embodiments 1-14, wherein the film has an elastic recovery after 100% strain of less than 95%.

[0074] Embodiment 16 is the method of any one of embodiments 1 to 15, wherein the film has an Index E100 of less than 9, Index E100 being calculated as breaking elongation×elastic recovery after 100% strain.

[0075] Embodiment 17 is the method of any one of embodiments 1-16, wherein the film has a yield strength of less than 30 N.

[0076] Embodiment 18 is the method of any one of embodiments 1 to 17, wherein the film has a non-zero yield strain.

[0077] Embodiment 19 is the method of any one of embodiments 1-18, wherein the hardenable dental composition is in the form of a self-supporting malleable structure.

[0078] Embodiment 20 is the method of any one of embodiments 1-19, wherein the hardenable dental article is a preformed hardenable dental article.

[0079] Embodiment 21 is the method of any one of embodiments 1 to 20, wherein the shape of the hardenable dental article is in the shape of a crown, inlay, onlay, bridge, veneer, tooth replica, temporary crown or restoration, implant healing cap, or dental splint.

[0080] Embodiment 22 is the method of any one of embodiments 1-21, wherein the shape of the hardenable dental article is the shape of a crown.

[0081] Embodiment 23 is an undeformed film having an elastic modulus of less than 900 MPa; and a hardenable dental article comprising the hardenable dental composition, wherein the undeformed film is separate from the hardenable dental article.

[0082] The following examples are intended to illustrate, but not limit, the present disclosure. [Example]

[0083] The objects and advantages of this invention are further illustrated by the following examples, but the particular materials and amounts recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. All parts and percentages are by weight unless otherwise specified. [Table 1]

[0084] Film 8 was a multilayer film prepared according to a coextrusion procedure similar to that described for Sample A in Example 1 of U.S. Patent No. 6,869,666, except that the core layer was made from ENGAGE 8200G (rather than KRATON D1107) and the skin layers (i.e., the outer layers on either side of the core layer) were made from PP 3155 (rather than HDPE A). Further details about Film 8, including the materials used in the core and skin layers, are provided in Table 2. Film 8 was therefore a three-layer elastomeric laminate having a skin-core-skin structure, with both skin layers being of the same composition and thickness. [Table 2]

[0085] Mechanical testing of films 1-10 Films 1-10 were tested on an Instron tensile testing machine Model #1122 (Norwood, MA) equipped with BLUEHILL2 software using a 200 lb (889 N) load cell, a 2.00 in (50.8 mm) jaw gap, and a ramp rate of 2 in / min (50.8 mm / min). The test procedure was a modification of test method ASTM D882 ("Standard Test Method for Tensile Properties of Thin Plastic Sheeting"). All film samples were tested at room temperature. Films 2 and 4-10 were cut into rectangular specimens >3.00 in (76.2 mm) long by 1.00 in (25.4 mm) wide. Films 1 and 3 had a pre-cut width of 0.50 in (12.7 mm) and were cut to lengths >3.00 in (76.2 mm). The film samples were loaded longitudinally into a tensile tester, and the ends of each sample were clamped into the test fixture. During testing, the film samples were stretched until failure (except for the 50% and 100% strain tests described below). Properties measured included modulus, elongation at break, yield, and yield strain.

[0086] Elastic recovery test after 50% and 100% strain Markings were made on a rectangular film sample spaced L0 = 1.00 inches (25.4 mm) apart. The test fixture was set 2.00 inches (50.8 mm) apart and the film sample was mounted longitudinally into the test fixture. The film sample was stretched to 50% tensile engineering strain, at which point the test was stopped and the length between the markings was calculated and recorded as L1. The film sample was removed from the apparatus and the length between the markings was measured and recorded as L2. The change between the markings was then used to calculate the percent elastic recovery after 50% strain. The percent elastic recovery after 50% strain was determined by the following equation: Elastic recovery after 50% strain = (L1-L2) / (L1-L0) Similar tests were performed (on virgin film samples) to a tensile engineering strain of 100% to also determine the percentage elastic recovery after 100% strain. The mechanical properties of Films 1-10 are summarized in Table 3. [Table 3]

[0087] Crown positioning and film evaluation Each of films 1-10 was evaluated for use in a crown placement and fitting procedure utilizing a self-supporting, malleable, light-cured composite crown. A typodont (Model R862, available from Columbia Dentoform, Long Island City, NY) was modified with a shoulder preparation at the #31 position (lower right second molar). A rectangular piece of a given film large enough (approximately 1.0-2.5 cm wide x >6 cm long) to cover the tooth preparation after placement was held at each end with a finger. The film was pulled tight (but not so tight as to permanently deform the film) and centered over the tooth preparation with the long axis of the rectangular film extending in a generally buccal-lingual direction. The instructed film was manually pulled down over the tooth preparation, deforming the film to completely cover the tooth casting. In most cases, the deformed film conformed tightly to the tooth preparation. Next, a malleable composite crown (DIRECTLY PLACED CROWN, mandibular molar, size large (11-12 mm), available from 3M ESPE, St. Paul, MN) was removed from its packaging (including the associated outer film packaging), and the crown was sized correctly to fit the tooth preparation by trimming the crown margins with scissors. The trimmed crown was then positioned onto the film-covered tooth preparation, with the film placed between the preparation and the positioned crown. The positioned crown was then customized and shaped to ensure a good marginal fit. The positioned crown was then blue-light cured using an EPILAR 2500 halogen curing light (available from 3M ESPE), with the buccal surface cured for 20 seconds, followed by the occlusal and lingual surfaces cured for 20 seconds each. The partially cured crown was removed from the film-covered tooth preparation, and the inner surface was blue-light cured for 20 seconds. The exterior surfaces of the fully cured crowns were finished and polished using standard techniques (utilizing a fine carbide dental cutting bur and a SOF-LEX finishing and polishing wheel (3M ESPE)).After removing the film, the finished and polished crown was placed back onto the prepared tooth of the typodont. Optionally, the cured crown may be further finished and / or adjusted and subsequently cemented into place.

[0088] The films were then qualitatively ranked from 1 (worst) to 5 (best) based on their performance in the crown positioning procedure before bonding. The best-performing films tended to (i) provide a cured crown that was easy to place back onto the film-free tooth preparation, (ii) provide a crown that fit well when the typodont arch was closed (i.e., no occlusal adjustments were required on the cured crown), and (iii) impart a minimal and relatively uniform margin gap between the cured crown and the tooth preparation (by visual inspection). The film performance rankings in the crown positioning procedure are summarized in Table 4. [Table 4]

[0089] Based on the mechanical properties of Films 1-10 in Table 3 and their associated performance ranking for crown positioning in Table 4, several observations can be made. Film 10, which had a high modulus, performed poorly. This film was stiff and did not conform to the dental preparation (resulting in a finished crown with a poor fit to the uncovered dental preparation). On the other hand, films with a low modulus, specifically films with a modulus of less than about 900 MPa (i.e., Films 1-9), were all tolerated in the procedure. Films with a modulus of less than about 300 MPa (e.g., Films 1-2 and 4) performed particularly well. Furthermore, Films 1-9 also exhibited relatively low yield forces (approximately 33 N or less), allowing dental professionals to more easily stretch and position the films over the dental preparation with less effort (i.e., finger / hand force). Finally, films with a relatively low % elongation at break and a low % recovery performed well, preferably with E50 and E100 Indexes of <3. For example, films with an elongation at break <300% and recovery <50% are easily stretched and can be partially deformed to adhere to tooth structure; these films have E50 and E100 numbers less than 3.

[0090] All references and publications cited herein are expressly incorporated herein by reference in their entirety into this disclosure. Exemplary embodiments of the present invention have been discussed, and reference has been made to possible variations within the scope of the present invention. For example, features described in connection with one exemplary embodiment may be used in connection with other embodiments of the present invention. These and other variations and modifications of the present invention will become apparent to those skilled in the art without departing from the scope of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Accordingly, the present invention should be limited only by the following embodiments and their equivalents. Some embodiments of the present disclosure are described in [Item 1] to [Item 15] below. [Item 1] positioning a film having an elastic modulus of less than 900 MPa over a dental structure to cover at least a portion of the dental structure; providing a hardenable dental article comprising a hardenable dental composition, the hardenable dental article including a base and an interior surface extending from the base; applying the hardenable dental article to the film-covered dental structure; A method comprising: [Item 2] providing a hardenable dental article comprising a hardenable dental composition, the hardenable dental article including a base and an interior surface extending from the base; placing a film having a modulus of elasticity of less than 900 MPa between the hardenable dental article and a dental structure; applying the hardenable dental article to the dental structure, wherein the film contacts at least a portion of the interior surface of the hardenable dental article. [Item 3] 3. The method of claim 1 or 2, further comprising customizing the shape of the hardenable dental article. [Item 4] 4. The method of any one of items 1 to 3, further comprising at least partially curing the hardenable dental article after the applying step. [Item 5] 5. The method of claim 4, wherein the film contacts at least a portion of the interior surface during the curing step. [Item 6] 5. The method of claim 4, further comprising trimming the hardenable dental article before the hardening step, after the hardening step, or both before and after the hardening step. [Item 7] 5. The method of claim 4, further comprising removing the film after the curing step. [Item 8] 8. The method of claim 7, wherein the inner film is removed in a single piece. [Item 9] 9. The method of any one of items 4 to 8, wherein the film is in contact with at least a portion of the surface of the dental structure during the customizing step or the curing step. [Item 10] 10. The method of any one of items 1 to 9, further comprising contouring and shaping the hardened dental article. [Item 11] 11. The method of any one of items 1 to 10, further comprising bonding the hardened dental article to the dental structure. [Item 12] 12. The method according to any one of items 1 to 11, wherein the film has an elastic modulus of less than 600 MPa. [Item 13] 13. The method according to any one of items 1 to 12, wherein the film has an elongation at break of less than 900%. [Item 14] 14. The method of any one of items 1 to 13, wherein the hardenable dental article is a preformed hardenable dental article. [Item 15] an undeformed film having an elastic modulus of less than 900 MPa; a hardenable dental article comprising a hardenable dental composition, wherein the undeformed film is separate from the hardenable dental article.

Claims

Claim 1: A method of using a hardenable dental article, comprising: positioning a film having a modulus of elasticity of 99 MPa or greater and less than 900 MPa over a dental structure to cover at least a portion of the dental structure; providing the hardenable dental article comprising a base and an interior surface extending from the base, the hardenable dental article comprising a hardenable dental composition; applying the hardenable dental article to the film-covered dental structure; hardening the hardenable dental composition to provide a hardened dental article; and removing the film from the dental structure after hardening; Including, the hardenable dental article is selected from a crown, a bridge, an implant, an artificial tooth, an inlay, an onlay, a veneer, a temporary restoration, an implant healing cap, a dental splint, an implant abutment, a coping, a post, a bridge structure, an abutment, and a maxillofacial prosthesis; The hardenable dental article is temporary, intermediate, or permanent; method.

2. The method of claim 1 , further comprising customizing the shape of the hardenable dental article.

3. The method of claim 1 , wherein the film contacts at least a portion of the interior surface during the curing.

4. The method of claim 1 , further comprising trimming the hardenable dental article before, after, or both before and after hardening.

5. The method of claim 1 , wherein the film is removed in a single piece.

6. The method of claim 2 , wherein the film contacts at least a portion of the surface of the dental structure during the customization.

7. The method of any one of claims 1 to 6, further comprising contouring and shaping the hardened dental article.

8. The method of any one of claims 1 to 7, further comprising bonding the hardened dental article to the dental structure.

9. The method of any one of claims 1 to 8, wherein the film has a modulus of elasticity of less than 600 MPa.

10. The method of any one of claims 1 to 9, wherein the hardenable dental article is a preformed hardenable dental article.

11. An undeformed film having an elastic modulus of 99 MPa or more and less than 900 MPa; a hardenable dental article comprising a hardenable dental composition; and a set of instructions for use instructing a user to carry out the method according to any one of claims 1 to 10, the undeformed film is separate from the hardenable dental article; the hardenable dental article is selected from a crown, a bridge, an implant, an artificial tooth, an inlay, an onlay, a veneer, a temporary restoration, an implant healing cap, a dental splint, an implant abutment, a coping, a post, a bridge structure, an abutment, and a maxillofacial prosthesis; Parts kit.

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