WO2021191773A1 - Dental appliance with graphic image - Google Patents

Abstract

A method for making a dental appliance includes depositing an image layer on a major surface of a water-soluble polymeric image carrier substrate; placing the water-soluble image carrier substrate in an aqueous liquid to at least partially dissolve the image carrier substrate; immersing into the aqueous liquid a substantially flat polymeric transfer substrate through the image layer such that the image layer transfers to a surface of the transfer substrate; and removing the transfer substrate from the aqueous liquid with the image layer bonded to the surface thereof. The transfer substrate may be formed into a dental appliance with a graphic image thereon.

Description

DENTAL APPLIANCE WITH GRAPHIC IMAGE

BACKGROUND

Orthodontic treatments reposition misaligned teeth and improve bite configurations for improved cosmetic appearance and dental function. Teeth are repositioned by applying controlled forces to the teeth over an extended time period. In one example, teeth may be repositioned by placing a dental appliance, generally referred to as an orthodontic aligner or an orthodontic aligner tray, over the teeth of the patient for each treatment stage of an orthodontic treatment. The orthodontic alignment tray includes a polymeric shell defining a plurality of cavities for receiving one or more teeth. The individual cavities in the polymeric shell are shaped to exert force on one or more teeth to resiliently and incrementally reposition selected teeth or groups of teeth in the upper or lower jaw.

A series of orthodontic aligner trays are provided to a patient to be worn sequentially and altematingly during each stage of the orthodontic treatment to gradually reposition teeth from one tooth arrangement to a successive tooth arrangement to achieve a desired tooth alignment condition Once the desired alignment condition is achieved, an aligner tray, or a series of aligner trays, may be used periodically or continuously in the mouth of the patient to maintain tooth alignment. In addition, orthodontic retainer trays may be used for an extended time period to maintain tooth alignment following the initial orthodontic treatment.

In some examples, a stage of orthodontic treatment may require that an aligner tray remain in the mouth of the patient for several hours a day, over an extended time period of days, weeks or even months. While the orthodontic aligner tray is in use in the mouth of the patient, microorganisms can contaminate the surface of the appliance, which in some cases can also cause biofilms to form on the surface. The biofdms can be difficult to remove, even if the appliance is periodically cleaned. Microorganisms or biofilm buildup on the surface of the aligner tray can stain or otherwise discolor the aligner tray, can cause undesirable tastes and odors, and even potentially lead to various periodontal diseases.

Coatings and patterns of therapeutic compounds, which have a beneficial effect in the mouth of a patient, have been applied to surfaces of dental or orthodontic appliances such as aligner trays to, for example, prevent the buildup of biofilms, reduce cavities, re-mineralize the teeth adjacent to the appliance, freshen breath, and the like. SUMMARY

Traditional printing is inexpensive, capable of wide formats at high speeds, and can reproducibly provide high quality images on a relatively flat substrate without complex curves and small crevasses. However, printing a graphic image on a three-dimensional surface like an orthodontic appliance can be difficult, and in some cases the printed ink does not reach small cavities and complex curves on the appliance, which detracts from the appearance and quality of the imaged surface.

The hydrographic or water transfer printing process has been used to form highly detailed images on two and three-dimensional objects made from a wide variety of materials such as, for example, plastic, fiberglass, wood, ceramics, and metal. In the water transfer printing process, a substrate undergoes the same steps as in conventional painting: 1) optional surface preparation, 2) optional priming, 3) optional painting, and 4) optional clear coating. However, in the water transfer printing process, the substrate is water transfer printed after the optional painting step but before the clear coating step.

In the water transfer printing step, an image carrier substrate including a water-soluble polymeric hydrographic film (for example, a clear polyvinyl alcohol (PVA) hydrographic film) that has been printed with an ink to form a desired graphic image is carefully placed in an aqueous solution in a dipping tank. The water-soluble transfer film underlying the image is water-soluble, and at least partially dissolves to leave an image layer of ink in the aqueous solution. An optional activator solution can then be applied to the image layer, which at least partially softens the components of the ink and forms an activated image layer without altering the structure and appearance of the overall image.

A transfer substrate is then immersed in the aqueous solution through the image layer, and the surface tension of the water causes the image layer to smooth itself around and conform to substantially all the surfaces of the transfer substrate. Any undeposited ink, excess image material, or residue of the water-soluble transfer film can optionally be rinsed away, following the transfer, and the image layer adhered to transfer substrate is then dried. The printed object having the image thereon can optionally be clear-coated to protect the transferred image from wear and provide the object with a desired shiny or matte surface appearance.

In one embodiment, the present disclosure is directed to method for applying a graphic image to a surface of a dental appliance that includes a plurality of cavities configured to retain one or more teeth. At least a portion of the image is applied to the dental appliance with a water transfer printing process. In some embodiments, the ink composition used to form the image includes at least one therapeutic compound that has a beneficial effect when the dental appliance is utilized in the mouth of the patient.

In another embodiment, the present disclosure is directed to a method for making a dental appliance. The method includes applying a graphic image to a substantially flat polymeric film substrate with a water transfer printing process. In some embodiments, the ink composition forming the image includes at least one therapeutic compound that has a beneficial effect when the dental appliance is utilized in the mouth of the patient. The imaged polymeric film substrate may then be formed into a dental appliance including a plurality of cavities configured to retain one or more teeth.

In one aspect, the present disclosure is directed to a method for making a dental appliance configured to position at least one tooth of a patient. The method includes depositing an image layer on a major surface of a water-soluble polymeric image carrier substrate; placing the water-soluble image carrier substrate on a surface of an aqueous liquid to at least partially dissolve the image carrier substrate; immersing into the aqueous liquid a substantially flat polymeric transfer substrate through the image layer such that the image layer transfers to a surface of the transfer substrate; removing the transfer substrate from the aqueous liquid with the image layer bonded to the surface thereof; and forming a plurality of cavities in the substantially flat transfer substrate to form a dental appliance including an arrangement of cavities configured to receive one or more teeth. The image layer adheres to a surface of the dental appliance and forms a graphic image thereon.

In another aspect, the present disclosure is directed to a method for applying a graphic image to a dental appliance. The method includes: printing a hardenable ink composition on a major surface of a water-soluble polymeric image carrier substrate to form on the major surface of the image carrier substrate an image layer; placing the water-soluble polymeric image carrier substrate on a surface of an aqueous liquid to at least partially dissolve the image carrier substrate; immersing into the aqueous liquid a dental appliance through the image layer such that the image layer transfers to a surface of a dental appliance, wherein the dental appliance includes a plurality of cavities configured to retain one or more teeth; removing the dental appliance transfer substrate from the aqueous liquid with the image layer bonded to the surface thereof such that the image layer adheres to a surface of the dental appliance and forms a graphic image thereon.

In another aspect, the present disclosure is directed to a method of forming a graphic image on a dental appliance. The method includes: selecting a water-soluble polymeric transfer film article with an image layer on a major surface of a water-soluble polymeric transfer film; placing the water- soluble polymeric transfer film substrate in an aqueous liquid; dipping a substantially flat polymeric film transfer substrate through the image layer and into the aqueous liquid such that the image layer transfers to a surface of the flat polymeric film transfer substrate; removing the substantially flat polymeric film transfer substrate from the aqueous liquid with the image layer bonded to the surface thereof; and forming a plurality of cavities in the substantially flat polymeric film substrate to form a dental appliance with an arrangement of cavities configured to receive one or more teeth, wherein the image layer adheres to a surface of the dental appliance and forms the graphic image thereon.

In another aspect, the present disclosure is directed to a method of forming a graphic image on a dental appliance. The method includes: selecting a water-soluble polymeric transfer film article with an image layer on a major surface of the transfer fdm; placing the water-soluble polymeric transfer film substrate in an aqueous liquid; inserting through the image layer and into the aqueous liquid a dental appliance with a plurality of cavities configured to receive one or more teeth such that the image layer transfers to a surface of the dental appliance; and removing the dental appliance from the aqueous liquid such that the image layer adheres to the surface of the dental appliance and forms the graphic image thereon.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A-1G are schematic cross-sectional views of an embodiment of a hydrographic printing process for making a dental appliance.

FIG. 2 is a schematic exploded view of a dental appliance as applied to teeth of a patient.

FIG. 3 includes photographs of PETg sheets and disks made with the water transfer process described in Example 1.

FIG. 4 is a photograph of a PETg disk with a water transfer printed image made according to Example 1, and the aligner tray produced from the PETg disk with a thermoforming process.

FIG. 5 includes photographs of prefabricated aligner trays (thermoformed or 3D printed) with a water transfer printed graphic image made according to Example 2.

Like symbols in the drawings indicate like elements.

DETAILED DESCRIPTION

FIGS. 1 A-1G are directed to a schematic depiction of a hydrographic transfer printing process that may be used to form a complex graphic image on a surface of a dental appliance, or on a surface of a polymeric film that is subsequently formed into a dental appliance. In some embodiments, which are not intended to be limiting, the dental appliance includes a wide variety of complex curves and depressions such as, for example, an orthodontic aligner tray or retainer tray. In FIG. 1 A an image carrier 10 includes an image layer 12 applied on a first major surface 15 of a water-soluble image carrier substrate 14. The image layer 12 includes a first exposed surface 19 and a second surface 21 contacting the first major surface of the water-soluble image carrier substrate 14. The water-soluble substrate also includes a second major surface 17 opposite the first major surface 15. In some embodiments, the image carrier substrate 14 and the water-soluble substrate each may be a single layer or a multilayer substrate.

The water-soluble image carrier substrate 14 may be selected from any material that is at least partially soluble in an aqueous solution or water over a commercially useful period of time. In various embodiments, which are not intended to be limiting, the water-soluble image carrier substrate 14 includes a water-soluble polymeric film including polyvinyl alcohol (PVA), ethylene vinyl acetate, carboxymethyl cellulose, polyanionic cellulose, hydroxypropyl methylcellulose, N-(2- Hydroxypropyljmethacrylamide (HPMA), polyethylene oxide (PEO), polyethylene glycol (PEG), polyacrylic acid (PAA), polyacrylamides, and polyvinylpyrrolidone (PVP). In some embodiments, the water-soluble image carrier substrate 14 itself (not including the graphic pattern) may be selected to be clear, transparent, translucent, or opaque.

The image layer 12 may be applied to the surface 15 using any suitable technique such as printing, coating, vapor deposition, or direct or indirect transfer of a material from a release surface at ambient temperature or with heat. Suitable printing techniques include, but are not limited to, screen printing, flexographic printing, inkjet printing, gravure printing, pad printing, intaglio printing, printing with a stencil, digital printing, and combinations thereof. In some embodiments, the surface 15 may include an optional adhesive layer (not shown in FIG. 1A) to bond the image layer 12.

The image layer 12 may be selected from a wide variety of complex graphics, pictures, or textures, and in some cases may include multiple colors. Suitable graphic images include, but are not limited to, an aesthetic pattern, a photographic image, a logo, a bar code, a QR code, arrays of geometric structure such as dots and spheres, grid patterns, and the like.

The image layer 12 may be a single layer as shown in FIG. 1 A, or may include multiple layers. The image layer 12 can cover all or a portion of the surface 15.

In one embodiment, the image layer 12 is formed from a metal, a metal oxide, a metal sulfide, and the like. Suitable processes for applying the metal image layer 12 include, but are not limited to, physical vapor deposition, chemical vapor deposition, sputtering, and the like. In some embodiments, the metal image layer may be applied to the surface 15 in an amount sufficient to substantially reduce or prevent microbial or biofilm formation on a dental appliance. In another embodiment, the image layer 12 is formed from a liquid ink composition including a hardenable liquid resin, at least one therapeutic agent, and optional components such as a liquid carrier, a pigment, and the like. In this application the term therapeutic agent refers to compounds that that can have a beneficial effect in the mouth of the patient. Examples of suitable therapeutic agents for the ink composition include, but are not limited to, fluoride sources, whitening agents, anticavity agents (e.g., xylitol), re-mineralizing agents (e.g., calcium phosphate compounds), enzymes, breath fresheners, anesthetics, clotting agents, acid neutralizers and pH control agents, ion-recharging agents, chemotherapeutic agents, immune response modifiers, thixotropes, polyols, anti-inflammatory agents, antimicrobial agents, antifungal agents, agents for treating xerostomia, desensitizers, and the like, of the type often used in dental compositions. Combinations of any of the above therapeutic agents may be used.

In some embodiments, suitable therapeutic agents for the liquid ink composition include remineralizing agents such as calcium, phosphorous, and fluoride compounds.

For example, in some embodiments, suitable calcium compounds in the hardenable liquid resin composition include, but are not limited to, calcium chloride, calcium carbonate, calcium caseinate, calcium chloride, calcium citrate, calcium glubionate, calcium gluceptate, calcium glycerophosphate, calcium gluconate, calcium hydroxide, calcium hydroxyapatite, calcium lactate, calcium oxalate, calcium oxide, calcium pantothenate, calcium phosphate, calcium polycarbophil, calcium propionate, calcium pyrophosphate, calcium sulfate, and mixtures and combinations thereof. These compounds have been found to minimize demineralization of calcium hydroxyapatite at the surface of the tooth of a patient.

In some embodiments, the tooth re-mineralizing compounds in the liquid ink composition include phosphate compounds. Suitable phosphate compounds include, but are not limited to, aluminum phosphate, bone phosphate, calcium phosphate, calcium orthophosphate, calcium phosphate dibasic anhydrous, calcium phosphate-bone ash, calcium phosphate dibasic dihydrate, calcium phosphate dibasic anhydrous, calcium phosphate dibasic dihydrate, calcium phosphate tribasic, dibasic calcium phosphate dihydrate, dicalcium phosphate, neutral calcium phosphate, precipitated calcium phosphate, tertiary calcium phosphate, tricalcium phosphate, whitlockite, magnesium phosphate, potassium phosphate, dibasic potassium phosphate, dipotassium hydrogen orthophosphate, dipotassium monophosphate, dipotassium phosphate, monobasic potassium phosphate, potassium acid phosphate, potassium biphosphate, potassium dihydrogen orthophosphate, potassium hydrogen phosphate, sodium phosphate, anhydrous sodium phosphate, dibasic sodium phosphate, disodium hydrogen orthophosphate, disodium hydrogen orthophosphate dodecahydrate, disodium hydrogen phosphate, disodium phosphate, and sodium orthophosphate. Fluoride compounds incorporated into the mineral surface of a tooth help inhibit the demineralization of enamel and protect the tooth. Fluoride compounds absorbed into mineral surfaces of a tooth attract calcium and phosphate ions from saliva, or other sources, which results in the formation of fluorapatite and protects the tooth against demineralization. While not wishing to be bound by any theory, currently available evidence indicates that fluorapatite exhibits lower solubility than naturally occurring hydroxyapatite, which can help resist the inevitable acid challenge that teeth face daily.

Orthodontic patients are considered high risk for cavities over the course of their treatment. Commercial fluoride varnishes are very sticky by design and typically last a few hours on the enamel once applied. For an orthodontic patient wearing a dental appliance such as an aligner tray, this is undesirable since the varnish can interfere with the fit of the aligners on the arches of the patient, as well as adhere to the plastic that the aligners are made from and permanently warp or deform them. In some embodiments, the calcium compounds, phosphate compounds, fluoride compounds or combinations thereof, are present in the liquid ink composition in an amount sufficient such at least one of calcium, phosphate or fluoride can substantially reduce cavities or demineralization on the surface of the teeth of the patient during or exceeding a predetermined wear time.

In another embodiment, the therapeutic agents in the liquid ink composition include compounds selected to reduce the bacteria or bio film on at least one of the surfaces of a dental appliance. Suitable antibacterial or biofilm-reducing compounds include, but are not limited to, biocompatible metals and metal oxides MO_x such as copper, silver, zinc, silver oxide, copper oxide, gold oxide, stannous oxide, zinc oxide, magnesium oxide, titanium oxide, chromium oxide, and mixtures, alloys and combinations thereof.

The liquid ink composition forming the image layer 12 can include any antimicrobially effective amount of the metal or the metal oxide MO_x. In various embodiments, which are not intended to be limiting, the liquid regions 14 can include less than 100 mg, less than 40 mg, less than 20 mg, or less than 5 mg MO_x per 100 cm². The metal oxide can include, but is not limited to, silver oxide, copper oxide, gold oxide, stannous oxide, zinc oxide, magnesium oxide, titanium oxide, chromium oxide, and mixtures, alloys and combinations thereof. In some embodiments, which are not intended to be limiting, the metal oxide can be chosen from AgCuZnOx, Ag doped ZnOx, Ag doped AZO, Ag doped Ti02, A1 doped ZnO, and TiOx.

In some embodiments, the liquid ink composition can include one or more antibacterial agents. Examples of suitable antibacterial agents can include, but are not limited to, aldehydes (glutaraldehyde, phthalaldehyde), salts of phenolics or acids, chlorhexidine or its derivatives (including acid adducts such as acetates, gluconates, chlorides, nitrates, sulfates or carbonates), and combinations thereof.

Non-limiting examples of suitable antibacterial agents for the liquid ink composition include: zinc salts, zinc oxide, tin salts, tin oxide (stannous oxide),, benzalkonium chloride, hexitidine, long chain alkyl ammonium or pyridinium salts (e.g., cetypyridinium chloride, tetradecylpyridinium chloride), essential oils (e.g., thymol), furanones, chlorhexidine and salt forms thereof (e g., chlorhexidine gluconate), sanguinarine, triclosan, stannous chloride, stannous fluoride, octenidine, non-ionic or ionic surfactants (e.g., quaternary ammonium compounds), alcohols (monomeric, polymeric, monoalcohols, poly -alcohols), aromatic alcohols (e.g., phenol)), antimicrobial peptides (e.g., histatins), bactericins (e.g., nisin), antibiotics (e.g., tetracycline), aldehydes (e.g., glutaraldehyde) inorganic and organic acids (e.g., benzoic acid, salicylic acid, fatty acids, etc.) or their salts, derivatives of such acids such as esters (e.g., p-hydroxybenzoates or other parabens, glycerol esters of fatty acids such as lauricidin (monolaurin)), silver compounds, silver salts, silver nanoparticles, peroxides (e.g., hydrogen peroxide), and combinations thereof.

In another embodiment, the liquid ink composition can include an elastomeric polymeric material selected to, for example, ease placement and removal of a dental appliance in the mouth of the patient when the image layer 12 is transferred to a surface of a dental appliance. In some embodiments, the ink composition forming the image layer 12 can be formulated to improve comfort against the teeth or the tissues in the mouth of the patient, or enhance tray-to-dentition contact area leading to lower stress and/or effective force transfer from the dental article for repositioning teeth. In some examples, suitable elastomers can include polyisoprenes, polybutadienes, chloroprene rubbers, butyl rubbers, halogenated butyl rubbers, fluoropolymers, nitriles, ethylene propylene rubbers, ethylene propylene diene rubbers, silicone rubbers, polyacrylic rubbers, fluorosilicones, fluoroelastomers, polyether block amides, cholorsulfinated polyethylenes, and ethylene vinyl acetates.

The liquid ink composition forming the image layer 12 includes a hardenable liquid resin. In some embodiments, the hardenable liquid resin has a glass transition temperature (T_g) higher than the T_g of the polymeric transfer substrate to which the image layer 12 is subsequently transferred to form the dental appliance. In some cases, utilizing a hardenable liquid resin having a higher T_g can reduce or substantially eliminate distortion when the transfer substrate is thermoformed into a dental appliance. In some embodiments, resins with a higher T_g can provide an image layer 12 with a greater height above the surface 15, a greater particle loading, and combinations thereof.

Suitable resins for the liquid ink composition include, but are not limited to, epoxy resins (which contain cationically active epoxy groups), vinyl ether resins (which contain cationically active vinyl ether groups), ethylenically unsaturated compounds (which contain free radically active unsaturated groups, e g., acrylates and methacrylates), and combinations thereof. Also suitable are polymerizable materials that contain both a cationically active functional group and a free radically active functional group in a single compound. Examples include epoxy -functional (meth)acrylates.

As used herein, ethylenically unsaturated compounds with acid functionality includes monomers, oligomers, and polymers having ethylenic unsaturation and acid and/or acid-precursor functionality. Acid-precursor functionalities include, for example, anhydrides, acid halides, and pyrophosphates. Ethylenically unsaturated compounds with acid functionality include, for example, a,b-unsaturated acidic compounds such as glycerol phosphate mono(meth)aciylates, glycerol phosphate di(meth)acrylates, hydroxyethyl (meth)acrylate (e.g., HEMA) phosphates, bis((meth)acryloxyethyl) phosphate, ((meth)acryloxypropyl) phosphate, bis((meth)acryloxypropyl) phosphate, bis((meth)acryloxy)propyloxy phosphate, (meth)acryloxyhexyl phosphate, bis((meth)acryloxyhexyl) phosphate, (meth)acryloxyoctyl phosphate, bis((meth)acryloxyoctyl) phosphate, (meth)acryloxydecyl phosphate, bis((meth)acryloxydecyl) phosphate, 10-methacryloyloxydecyl dihydrogen phosphate (MDP monomer), caprolactone methacrylate phosphate, citric acid di- or tri-methacrylates, poly(meth)acrylated oligomaleic acid, poly(meth)acrylated polymaleic acid, poly(meth)acrylated poly(meth)acrylic acid, poly(meth)aciylated polycaiboxyl-polyphosphonic acid, poly(meth)acrylated polychlorophosphoric acid, poly(meth)acrylated poly sulfonate, poly(meth)acrylated polyboric acid, and the like, may be used as components in the hardenable resin system. Also, monomers, oligomers, and polymers of unsaturated carbonic acids such as (meth)aciylic acids, aromatic (meth)aciylated acids (e.g., methacrylated trimellitic acids), and anhydrides thereof can be used. Some compositions can include an ethylenically unsaturated compound with acid functionality having at least one P — OH moiety.

In some embodiments, the hardenable liquid ink composition may be photopolymeiizable. Photopolymerizable compositions may include compounds having free radically active functional groups that may include monomers, oligomers, and polymers having one or more ethylenically unsaturated group. Suitable compounds contain at least one ethylenically unsaturated bond and are capable of undergoing addition polymerization. Such free radically polymerizable compounds include mono-, di- or poly-(meth)acrylates (i.e., acrylates and methacrylates) such as, methyl (meth)acrylate, ethyl acrylate, isopropyl methacrylate, n-hexyl acrylate, stearyl acrylate, allyl acrylate, glycerol triacrylate, ethyleneglycol diacrylate, diethyleneglycol diacrylate, triethyleneglycol dimethacrylate,

1.3-propanediol di(meth)acrylate, trimethylolpropane triacrylate, 1,2,4-butanetriol trimethacrylate,

1.4-cyclohexanediol diacrylate, pentaerythritol tetra(meth)acrylate, sorbitol hexacrylate, tetrahydrofurfuryl (meth)acrylate, bis[l-(2-acryloxy)]-p-ethoxyphenyldimethylmethane, bis[l-(3- acryloxy-2-hydroxy)]-p-propoxyphenyldimethylmethane, ethoxylated bisphenolA di(meth)acrylate, and trishy droxyethyl-isocyanurate trimethacrylate; (meth)acrylamides (i.e., acrylamides and methacrylamides) such as (meth)acrylamide, methylene bis-(meth)acrylamide, and diacetone (meth)acrylamide; urethane (meth)acrylates; the bis-(meth)acrylates of polyethylene glycols (e.g., molecular weight 200-500), copolymerizable mixtures of acrylated monomers such as those in U S. Pat. No. 4,652, 274 (Boettcher et al.), acrylated oligomers such as those of U.S. Pat. No. 4,642,126 (Zador et al ), and poly(ethylenically unsaturated) carbamoyl isocyanurates such as those disclosed in U.S. Pat. No. 4,648,843 (Mitra); and vinyl compounds such as styrene, diallyl phthalate, divinyl succinate, divinyl adipate and divinyl phthalate. Other suitable free radically polymerizable compounds include siloxane-functional (meth)acrylates as disclosed, for example, in WO-OO/38619 (Guggenberger et al.), WO-Ol/92271 (Weinmann et al.), WO-01/07444 (Guggenberger et al.), WO- 00/42092 (Guggenberger et al.) and fluoropolymer-functional (meth)acrylates as disclosed, for example, in U.S. Pat. No. 5,076,844 (Fock et al.), U.S. Pat. No. 4,356,296 (Griffith et al.), EP-0373 384 (Wagenknecht et al.), EP-0201 031 (Reiners et al.), and EP-0201 778 (Reiners et al). Mixtures of two or more free radically polymerizable compounds can be used if desired.

The polymerizable component in the hardenable liquid ink composition may also contain hydroxyl groups and free radically active functional groups in a single molecule. Examples of such materials include hydroxyalkyl (meth)acrylates, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; glycerol mono- or di-(meth)acrylate; trimethylolpropane mono- or di-(meth)acrylate; pentaerythritol mono-, di-, and tri-(meth)acrylate; sorbitol mono-, di-, tri-, tetra-, or penta- (meth)acrylate; and 2,2-bis[4-(2-hydroxy-3-methaciyloxypropoxy)phenyl]propane (bisGMA). Suitable ethylenically unsaturated compounds are also available from a wide variety of commercial sources, such as Sigma-Aldrich, St. Louis. Mixtures of ethylenically unsaturated compounds can be used if desired.

Particularly useful photopolymerizable components for use in the hardenable liquid ink composition include PEGDMA (polyethyleneglycol dimethaciylate having a molecular weight of approximately 400), bisGMA, UDMA (urethane dimethacrylate), GDMA (glycerol dimethacrylate), TEGDMA (triethyleneglycol dimethacrylate), bisEMA6 as described in U.S. Pat. No. 6,030,606 (Holmes), and NPGDMA (neopentylglycol dimethacrylate). Various combinations of the polymerizable components can be used if desired.

For example, some embodiments of the hardenable liquid ink composition can include approximately at least 10, 20, 30, 40, 50, 60, 70, 80, 85, 90, 92, 95, 96, 98 or 99% by weight of photopolymerizable components, based on the total weight of the composition. In some embodiments, the hardenable liquid ink composition can include approximately less than 10, 20, 30, 40, 50, 60, 70, 80, 85, 90, 92, 95, 96, 98 or 99% by weight of photopolymerizable components, based on the total weight of the composition. In some embodiments, the hardenable liquid ink composition can include a range, e.g., between approximately 10% by weight to approximately 99% by weight, between approximately 10% by weight to approximately 50% by weight, between approximately 50% by weight to approximately 99% by weight, or between approximately 40% by weight to approximately 70% by weight of photopolymerizable components, based on the total weight of the composition.

In one embodiment, the hardenable liquid ink composition includes as photopolymerizable components approximately at least 10, 15, 20, 25, 30, or 40% by weight of one or more ethylenically unsaturated compounds, based on the total weight of the composition. In some embodiments, the hardenable liquid ink composition, includes as photopolymerizable components approximately less than 60, 70, 75, 80, 85, or 90% by weight of one or more ethylenically unsaturated compounds, based on the total weight of the composition. In other embodiments, the hardenable liquid ink composition includes as photopolymerizable components between approximately 10% by weight to approximately 90% by weight, between approximately 10% by weight to approximately 40% by weight, between approximately 60% by weight to approximately 90% by weight, or between approximately 40% by weight to approximately 70% by weight of one or more ethylenically unsaturated compounds, based on the total weight of the composition.

In one embodiment, the hardenable liquid ink composition includes approximately at least 10, 15, 20, 25, 30, or 40% by weight of photopolymerizable components of one or more ethylenically unsaturated compounds with acid functionality and an initiator system, based on the total weight of the resin composition. In some embodiments, the hardenable liquid ink composition includes approximately less than 60, 70, 75, 80, 85, or 90% by weight of photopolymerizable components of one or more ethylenically unsaturated compounds with acid functionality and an initiator system, based on the total weight of the composition. In other embodiments, the hardenable liquid ink composition includes between approximately 10% by weight to approximately 90% by weight, between approximately 10% by weight to approximately 40% by weight, between approximately 60% by weight to approximately 90% by weight, or between approximately 40% by weight to approximately 70% by weight of photopolymerizable components of one or more ethylenically unsaturated compounds with acid functionality and an initiator system, based on the total weight of the resin composition.

Suitable photoinitiators (i.e., photoinitiator systems that include one or more compounds) for polymerizing free radically photopolymerizable resin compositions include binary and tertiary systems. Typical tertiary photoinitiators include an iodonium salt, a photo sensitizer, and an electron donor compound as described in U.S. Pat. No. 5,545,676 (Palazzotto et ah). Iodonium salts can include the diaryl iodonium salts, e.g., diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, diphenyliodonium tetrafluoroborate, and tolylcumyliodonium tetrakis(pentafluorophenyl)borate. Photo sensitizers can include monoketones and diketones that absorb some light within a range of 400 nm to 520 nm, or 450 nm to 500 nm. Compounds can include alpha diketones that have some light absorption within a range of 400 nm to 520 nm or of 450 nm to 500 nm. Compounds can include camphorquinone, benzil, furil, 3, 3,6,6- tetramethylcyclohexanedione, phenanthraquinone, l-phenyl-l,2-propanedione and other l-aryl-2- alkyl-l,2-ethanediones, and cyclic alpha diketones. Electron donor compounds can include substituted amines, e.g., ethyl dimethylaminobenzoate. Other suitable tertiary photoinitiator systems useful for photopolymerizing cationically polymerizable resins are described, for example, in U.S.

Pat. Publication No. 2003/0166737 (Dede et ah).

Other suitable photoinitiators for polymerizing free radically photopolymerizable compositions include the class of phosphine oxides that typically have a functional wavelength range of 380 nm to 1200 nm. Phosphine oxide free radical initiators with a functional wavelength range of 380 nm to 450 nm can include acyl and bisacyl phosphine oxides such as those described in U.S. Pat. No. 4,298,738 (Lechtken et ah), U.S. Pat. No. 4,324,744 (Lechtken et ah), U.S. Pat. No. 4,385,109 (Lechtken et ah), U.S. Pat. No. 4,710,523 (Lechtken et ah), and U.S. Pat. No. 4,737,593 (Ellrich et ah), U.S. Pat. No. 6,251,963 (Kohler et ah); and EP Application No. 0 173 567 A2 (Ying).

In one embodiment, the hardenable liquid ink composition includes an effective amount from approximately 0.1 wt% to approximately 5.0 wt% of one or more photoinitiators, based on the total weight of the composition.

The hardenable liquid ink composition can also contain fdlers such as those suitable for incorporation in compositions used for dental applications, such as fillers currently used in dental restorative compositions, pigments, and the like.

The filler can be finely divided. The filler can have a unimodial or polymodial (e.g., bimodal) particle size distribution. In some examples, the maximum particle size (the largest dimension of a particle, typically, the diameter) of the filler can be less than 20 micrometers, less than 10 micrometers, or less than 5 micrometers. In some examples, the average particle size of the filler can be less than 0.1 micrometers or less than 0.075 micrometer.

The filler can be an inorganic material. It can also be a crosslinked organic material that is insoluble in the resin system and is optionally filled with inorganic filler. The filler should in any event be nontoxic and suitable for use in the mouth. The filler can be radiopaque or radiolucent, and in some embodiments is substantially insoluble in water. Examples of suitable inorganic fillers are naturally occurring or synthetic materials including, but not limited to: quartz; nitrides (e.g., silicon nitride); glasses derived from, for example, Zr, Sr, Ce, Sb, Sn, Ba, Zn, and Al; feldspar; borosilicate glass; kaolin; talc; titania; pigments; low Mohs hardness fillers such as those described in U.S. Pat. No. 4,695,251 (Randklev); and submicron silica particles (e.g., pyrogenic silicas such as those available under the trade designations AEROSIL, including “OX 50,” “130,” “150” and “200” silicas from Degussa Corp., Akron, Ohio and CAB-O-SIL M5 silica from Cabot Corp , Tuscola, Ill.). Examples of suitable organic filler particles include filled or unfilled pulverized polycarbonates, polyepoxides, and the like.

Non-acid-reactive filler particles can include quartz, submicron silica, and non-vitreous microparticles of the type described in U.S. Pat. No. 4,503,169 (Randklev). Mixtures of these non-acid-reactive fillers are also contemplated, as well as combination fillers made from organic and inorganic materials. In some embodiments, the filler can be silane-treated zirconia-silica (Zr — Si).

For some embodiments that include filler, the hardenable liquid ink composition can include at least 1% by weight, at least 2% by weight, and at least 5% by weight filler, based on the total weight of the composition.

The hardenable liquid ink composition also includes an optional solvent or a liquid carrier, which can vary widely. In some embodiments, the solvents and liquid carriers are aqueous, or consist of, water.

In some embodiments, the hardenable liquid ink composition includes less than about 1% by weight of optional additives such as, for example, preservatives (for example BHT), flavoring agents, indicators, dyes, pigments, inhibitors, accelerators, viscosity modifiers, wetting agents, buffering agents, radical and cationic stabilizers (for example BHT), and the like, based on the total weight of the composition.

Referring now to FIG. IB, a transfer construction 22 includes a transfer substrate 24 with a surface 25 configured to accept the transfer of the image layer 12. In one embodiment, the transfer substrate 24 is a polymeric material that, following the transfer of the image layer 12, may be formed into a dental appliance including a plurality of cavities configured to retain one or more teeth. In another embodiment, the transfer substrate 24 is a polymeric material that has been previously formed into a dental appliance including a plurality of cavities configured to retain one or more teeth by thermoforming a polymeric film, three-dimensional (3D) printing, and the like. While the surface 25 that accepts the transfer of the image layer 12 is shown as a substantially flat surface in FIG. IB, in some embodiments the surface 25 includes complex curves, depressions, and the like. The transfer substrate 24 may be selected from any suitable elastic polymeric material that is moldable to form a dental appliance, and once molded is generally conformable to a patient's teeth. The transfer substrate 24 may be transparent, translucent, or opaque. In some embodiments, the transfer substrate 24 is a clear or substantially transparent polymeric material that may include, for example, one or more of amorphous thermoplastic polymers, semi-crystalline thermoplastic polymers and transparent thermoplastic polymers chosen from polycarbonate, thermoplastic polyurethane, acrylic, polysulfone, polyprolylene, polypropylene/ethylene copolymer, cyclic olefin polymer/copolymer, poly-4-methyl-l-pentene or polyester/polycarbonate copolymer, styrenic polymeric materials, polyamide, polymethylpentene, polyetheretherketone and combinations thereof. In another embodiment, the transfer substrate 24 may be chosen from clear or substantially transparent semi-crystalline thermoplastic, crystalline thermoplastics and composites, such as polyamide, polyethylene terephthalate. polybutylene terephthalate, polyester/polycarbonate copolymer, polyolefin, cyclic olefin polymer, styrenic copolymer, polyetherimide, polyetheretherketone, polyethersulfone, polytrimethylene terephthalate, and mixtures and combinations thereof. In some embodiments, the transfer substrate 24 is a polymeric material chosen from polyethylene terephthalate, polyethylene terephthalate glycol, polycyclohexylenedimethylene terephthalate glycol, and mixtures and combinations thereof. One example of a commercially available material suitable as the elastic polymeric material for the transfer substrate 24, which is not intended to be limiting, is polyethylene terephthalate (polyester with glycol additive (PETg)).

Suitable PETg resins can be obtained from various commercial suppliers such as, for example, Eastman Chemical, Kingsport, TN; SK Chemicals, Irvine, CA; DowDuPont, Midland, MI; Pacur, Oshkosh, WI; and Scheu Dental Tech, Iserlohn, Germany.

The transfer substrate 24 may be made of a single polymeric material or may include multiple layers of the same or different polymeric materials.

In various embodiments, the transfer substrate 24 has a thickness of less than 1 mm, but varying thicknesses may be used depending on the application of the orthodontic appliance 100. In various embodiments, the transfer substrate 24 has a thickness of about 50 pm to about 3,000 pm, or about 300 pm to about 2,000 pm, or about 500 pm to about 1,000 pm, or about 600 pm to about 700 pm.

In one embodiment, the transfer substrate 24 is a substantially transparent polymeric material, which in this application refers to materials that pass light in the wavelength region sensitive to the human eye (about 0.4 micrometers (pm) to about 0.75 pm) while rejecting light in other regions of the electromagnetic spectrum. In some embodiments, the transfer substrate 24 is substantially transparent to visible light of about 400 nm to about 750 nm at a thickness of about 50 pm to about 1000 pm. In various embodiments, the visible light transmission through the combined thickness of the substrate is at least about 75%, or about 85%, or about 90%, or about 95%, or about 99%. In various embodiments, the transfer substrate 24 has a haze of about 0% to about 20%, or about 1% to about 10%, or about 3% to about 8%. In various embodiments, the transfer substrate 24 has a clarity of about 75% to about 100%, or about 85% to about 99%, or about 90% to about 95%. The optical properties of the transfer substrate 24 can be measured using standards such as ASTM D 1003 by a wide variety of optical instruments such as, for example, those available under the trade designation Haze Guard from BYK Gardner, Columbia, MD

In some embodiments, the surface 25 to which the image layer 12 is to be transferred may optionally be chemically or mechanically treated to improve adhesion to the image layer 12. In some embodiments, the surface 25 may be treated with corona treatments, ozonation, and the like. In some embodiments, the surface 25 may include a layer 26 of a chemical composition selected to improve adhesion of the image layer 12. Suitable layer 26 include silane coupling agents, primers, adhesives, and mixtures and combinations thereof. The primer or coupling layer 26 includes an exposed surface 27 configured to adhesively bond with a transferred image layer. Examples of primer layer materials, which are not intended to be limiting, include commercially available products such as those available under the trade designations All-purpose primer from Hydro-dip, Baker City, OR, Automotive Enamel Gloss from Rust-oleum, Vernon Hills, IL, and Crystal Clear Enamel from Rust-oleum.

In some embodiments, the surface 25 of the transfer substrate 24 may optionally include a colorized layer (not shown in FIG. IB) to provide a desired background color or texture for a transferred image. In some embodiments, the transfer substrate 24 may also include a colorant.

Referring now to FIG. 1C, the image carrier 10 is placed in a bath 30 including an aqueous solution 32 such that the second major surface 17 of the water-soluble image carrier substrate 14 opposite the image layer 12. In some embodiments, at least a portion of the image carrier 10 floats on a surface 33 of the aqueous solution 32. In various embodiments, when the liquid ink composition forming the image layer 12 includes a hardenable liquid resin, the image layer 12 can optionally be hardened prior to or after the image carrier is placed in the bath 30. The hardening step can be conducted by appropriate means, for example by drying, thermal curing, photocuring and mixtures and combinations thereof.

The aqueous solution 32 includes water, and in some embodiments consists of water. In some embodiments, the aqueous solution 32 may optionally include solvents to assist in the dissolution of the water-soluble image carrier substrate 14 such as, for example, xylene, ethyl benzene, isobutanol, dioctyl phthalate, and methyl isobutyl ketone, and the like. In various embodiments, the aqueous solution 32 is generally at room temperature (about 20-30 °C), but the temperature of the aqueous solution 32 may be adjusted as needed to assist in the dissolution of the water-soluble image carrier substrate 14.

In some embodiments, an optional activator composition may be applied to the image layer 12, or included in the aqueous solution 32, or both. The activator composition may be formulated to speed the dissolution of the water-soluble image carrier 14, to soften the image layer 12, or both. In some embodiments, the activator composition includes plasticizers or softening agents such as, for example, those available from Hydro-Dip, Baker City, OR, under the trade designation HYDRO-SHIZZ. In some embodiments, the activator may be configured to activate a binding agent in the hardenable ink composition forming the image layer 12.

Referring now to FIG. ID, after a commercially useful period of time elapses, for example, about less than 10 seconds, less than 30 seconds, less than 1 minute, less than 5 minutes, the water-soluble image carrier substrate 14 at least partially dissolves in the aqueous solution 32, leaving the image layer 12 floating on the surface 33.

As shown in FIG. IE, the transfer construction 22 is then inserted along the direction of the arrow A into the aqueous solution 32 through the floating image layer 12. During the insertion step the exposed surface 27 of the primer or coupling layer 26 (or the exposed layer 25 of the transfer substrate 24 if the primer or coupling layer 26 is not present) contacts the exposed surface 19 of the image layer 12. The surface 19 of the image layer 12 adheres, wraps about and conforms to the surface 27 of the transfer substrate 25 as the image layer transfers to the transfer construction 22.

In an alternative embodiment the transfer construction 22 is then inserted in a direction in which arrow A is substantially perpendicular to the aqueous solution 32 through the floating image layer 12. In still another embodiment, the transfer construction 22 is already present submerged below the surface of the aqueous solution 32 before the image carrier 10 is placed in a bath 30 including an aqueous solution 32 (as described above referring to FIG. 1C); the transfer construction 22 is then raised out of the aqueous solution 32, through the floating image layer 12, as image layer 12 adheres, wraps about and conforms to the surface 27 of the transfer substrate 25 as the image layer transfers to the transfer construction 22.

Referring now to FIG. IF, after the transfer is complete, the surface 19 of the image layer 12 is bonded to the surface 27 of the primer or coupling layer 26 on the transfer substrate 24 to form a graphic article 40. Following the transfer, in some embodiments when the liquid ink composition forming the image layer 12 includes a hardenable liquid resin, the image layer 12 can optionally be hardened prior to or after the transfer step by appropriate means, for example by drying, thermal curing, photocuring, or mixtures and combinations thereof.

Following the transfer, in some embodiments water or other optional rinsing or finishing solutions may be applied to the image layer 12 to remove any residual aqueous solution 32 or further dissolve any remaining portions of the image carrier substrate 14 remaining on the surface 27.

In some embodiments, the transferred image layer 12 can optionally be dried following the transfer step.

In some embodiments, an optional protective topcoat layer 42 may be applied over the image layer 12 to protect the exposed surface 21 of layer 12. For example, the protective layer 42 may be a clear coat layer selected to provide a glossy or matte finish, a colored layer, or combinations thereof.

As shown schematically in FIG. 1G, the transfer substrate 24 may then be further processed to form an orthodontic appliance 50 with a final image 12A. The orthodontic appliance 50 includes a plurality of cavities configured to retain one or more teeth of a patient (not shown in schematic diagram of FIG. 1G). The cavities may be formed by any suitable technique, including thermoforming, laser processing, chemical or physical etching, and combinations thereof.

In various embodiments, the final image 12 A may occupy all or a selected portion of the surface 27 (or the surface 25 if the primer or coupling layer 26 is not present) of the orthodontic appliance 50.

In addition, in some embodiments various areas of the image 12 A can be configured to release the same or different therapeutic agents. For example, fluoride can be released from the image 12A in a first area of the surface 27, and phosphate can be released from the image 12A in a second area different from the first area. In other examples, the therapeutic agents released from the image 12A can vary within a given area of the surface 27. In another embodiment, the therapeutic agents within the image 12 A can be released at different concentrations between regions and within a selected region of the surface 27.

In another embodiment, the therapeutic agents released from the image 12 A can be releasable over a predetermined patient wear time of the dental appliance 50. In some examples, the therapeutic agents may be released over a period of seconds, minutes, hours, days, weeks, or months. In addition, different regions of the orthodontic appliance can have therapeutic agents with varying predetermined release periods. For example, one region may have a release period on the order of seconds, and another different region may have a release period on the order of months. In one example embodiment, the image 12 A can be configured to deliver, beneficial fluoride over a typical wear time for a dental appliance such as an alignment tray set (for example, 7 days), without compromising the fit of the alignment tray for the patient or mining the polymeric material from which the alignment tray is made.

In another embodiment, the image 12 A can provide an antimicrobial or antibiofilm effect on the surface 27 of the dental appliance 50. For example, the image 12A can provide at least a 2-log microbial reduction against S. aureus and S. mutans following 24 hour contact, or at least a 3 -log microbial reduction against S. aureus and S. mutans following 24 hour contact, or at least a 4-log microbial reduction against S. aureus and S. mutans following 24 hour contact.

In another embodiment, the image 12A can be configured to not only release therapeutic agents, but to also temporarily absorb therapeutic agents, such that the image 12A can be recharged with one or more therapeutic agents after previously releasing one or more therapeutic agents. An initial charging or periodic recharging of the image 12 A with one or more therapeutic agents may be accomplished, for example, by removing and soaking the orthodontic appliance 400 or 50 in a solution of the one or more therapeutic agents for a period of time sufficient to increase the amount of one or more therapeutic agents contained in the image 12A, prior to the next usage by the patient. Alternatively, a patient could gargle with a solution of the one or more therapeutic agents, while the orthodontic appliance 400 or 50 was still installed in the mouth. For example, calcium and/or phosphorus can be absorbed from saliva and released over time. In another example, fluoiide, calcium, tin, and/or phosphorus can be absorbed from oral care products (e.g., toothpaste and rinse) and released over time.

In some embodiments, the image 12A can be configured to facilitate unhindered flow of salivary fluids and other fluids to enhance and/or maintain hard tissue health on a surface of the dental appliance 50. For example, when a tooth surface undergoes demineralization instigated by oral bacteria, dietary choices, xerostomia, etc., the image 12A can provide open channels for the saliva to re-mineralize and hydrate the tooth surface.

In some embodiments, the tooth-retaining cavities are formed in the transfer substrate 24 under processing conditions such that the image layer 12 is not substantially distorted when forming the image 12A on the formed dental appliance 50. For example, in some embodiments, the transfer substrate 24 may be thermoformed at a temperature and pressure that distorts the image layer 12 by less than about 100%, or less than about 50%, in any dimension (for example, diameter, height, and the like) in forming the image 12A. In some embodiments, the transfer substrate 24 may be thermoformed at a temperature and a pressure such that the image layer 12 is not substantially distorted in creating the image 12A, which means that the image 12 A is still recognizable at a normal viewing distance. In some embodiments, the conditions in the thermoforming step may be utilized to change an initial image in the image layer 12 into a second pattern or image 12 A on the dental appliance 50, wherein the first and second images are different.

To more precisely control the change in the image layer 12 on the transfer substrate 24 into the graphic image 12A on the dental appliance 50, to more precisely align the image 12A on the surface 27, or to more precisely place the image 12A in a selected region of the surface 27, in some embodiments advanced image alignment techniques such as computational hydrographic printing may be used. For example, some basic aspects of computational hydrographic printing are described in Zhang et al., Computational Hydrographic Printing, ACM TOG 34(4), which is incorporated by reference herein. Computational hydrographic printing can enable more precise alignment of graphic patterns or images to complex 3D surfaces. Briefly, in computational hydrographic printing a computational model of the image is produced, which can be used to precisely register points on the image layer 12 to selected regions of the surface 27 to form the image 12A on the dental appliance 50.

In some embodiments, for example, to align the image layer 12 to specific areas on the surface 27, the transfer construction 22 and the image carrier 10 can be manipulated by a mechanical system as the transfer construction 22 is dipped into the aqueous carrier 32 and inserted through the image layer 12 (FIG. IE). In some cases, multiple immersions can be used with to apply multiple image layers to the surface 27 of the transfer construction 22. In other cases, specific image layers, or even image layers with specific colors, can be applied to different orientations of the image carrier substrate 22, so the combined colors of the individual immersions form a desired texture or final image 12A on the surface 27.

Referring now to FIG. 2, a shell 402 of a dental appliance 400 is an elastic polymeric material that generally conforms to a patient's teeth 500, but that is slightly out of alignment with the patient's initial tooth configuration. In some embodiments, the shell 402 may be one of a group or a series of shells having substantially the same shape or mold, but which are formed from different materials to provide a different stiffness or resilience as need to move the teeth of the patient. In this manner, in one embodiment, a patient or a user may alternately use one of the orthodontic appliances during each treatment stage depending upon the patient's desired usage time or treatment time period for each treatment stage.

No wires or other means may be provided for holding the shell 402 over the teeth 500, but in some embodiments, it may be desirable or necessary to provide individual anchors on teeth with corresponding receptacles or apertures in the shell 402 so that the shell 402 can apply a retentive or other directional orthodontic force on the tooth which would not be possible in the absence of such an anchor.

The shells 402 may be customized, for example, for day time use and night time use, during function or non-function (chewing vs. non-chewing), during social settings (where appearance may be more important) and nonsocial settings (where the aesthetic appearance may not be a significant factor), or based on the patient's desire to accelerate the teeth movement (by optionally using the more stiff appliance for a longer period of time as opposed to the less stiff appliance for each treatment stage).

For example, in one aspect, the patient may be provided with a clear dental appliance 400 that may be primarily used to retain the position of the teeth, and an opaque orthodontic appliance that may be primarily used to move the teeth for each treatment stage. Accordingly, during the daytime, in social settings, or otherwise in an environment where the patient is more acutely aware of the physical appearance, the patient may use the clear appliance. Moreover, during the evening or nighttime, in non-social settings, or otherwise when in an environment where physical appearance is less important, the patient may use the opaque appliance that is configured to apply a different amount of force or otherwise has a stiffer configuration to accelerate the teeth movement during each treatment stage. This approach may be repeated so that each of the pair of appliances are alternately used during each treatment stage.

Referring again to FIG. 2, systems and method in accordance with the various embodiments include a plurality of incremental position adjustment appliances, each formed from the same or a different material, for each treatment stage of dental or orthodontic treatment. The dental appliances may be configured to incrementally reposition individual teeth in an upper or lower jaw 502 of a patient. In some embodiments, the cavities in the dental appliance are configured such that selected teeth will be repositioned, while others of the teeth will be designated as a base or anchor region for holding the repositioning appliance in place as it applies the resilient repositioning force against the tooth or teeth intended to be repositioned.

Placement of the elastic positioner shell 402 over the teeth 500 applies controlled forces in specific locations to gradually move the teeth into the new configuration. Repetition of this process with successive appliances having different configurations eventually moves a patient's teeth through a series of intermediate configurations to a final desired configuration.

In one example embodiment, the orthodontic alignment appliances may include a shell 402 made from a clear elastomeric polymeric material and are referred to as a clear tray aligner (CTA). In use, CTAs at stage one (N) of treatment are inserted over a dental arch with misaligned or malocclusion dentition at stage zero (N-l). The polymeric tray can be stretched to force the dentition to reposition into the next stage one (N). In other words, each aligner tray starts out “ill-fitting” on purpose. The polymeric tray may have a contoured surface to be able to engage and transfer forces to the dentition to effectively reposition the right tooth or set of teeth at a designated location, vector and time. Because of the ability of the polymeric tray to engage and/or transfer forces to the dentition while starting out “ill-fitting,” the CTA can be effective and or efficient appliance for, e.g., correcting Class II malocclusions, more comfortable to patient, easy to place/remove, and providing predictable treatment outcome. Therefore, a polymeric aligner tray with some flexibility at least in part because of its flat surface may be able to engage and/or transfer forces to the dentition to effectively reposition the right tooth or set of teeth at a designated location, vector and time. Because of the fit between the tooth or set of teeth, the CTA can be effective and/or efficient appliance for correcting Class II malocclusions and be comfortable to the patient, easy to place/remove, predictable treatment outcome, etc.

Embodiments will now be illustrated with reference to the following non-limiting examples.

EXAMPLES

Materials

Water transfer print coatings were deposited on 1) PETg films (Scheu Dental Tech, Great Lakes, Tonawanda, NY, and Pacur, Oshkosh, WI, each 0.75 mm thick) and on 2) pre-formed PETg aligner trays.

In the first case, a color graphic image was deposited on single side of PETg sheet before thermoforming the sheet into a dental aligner tray.

In the second case, the outside/inside surface of already prepared aligner tray (thermoformed or 3D printed) was water transfer coated with a graphic image.

PVA hydrographic film, activator solution, all-purpose primers and clear coat were used for generating graphics.

The PVA hydrographic film (Oil Slick, Tabletop Wood Grain, Blue Camo, Purple Orchid, etc.) was purchased from Hydro-Dip Inc., Baker City, OR, and blank hydrographic film was purchased from Tsautop Hydrographies, Hangzhou City, China.

The activator solution was obtained from Hydro-Dip under the trade designation Hydro-Shizz.

An all-purpose primer was obtained from Hydro-dip, while Automotive Enamel Gloss and Crystal Clear Enamel were obtained from Rust-oleum, Vernon Hills, IL.

Clearcoat gloss was obtained from Hydro-dip and Crystal Clear enamel was obtained from Rust- oleum.

Methods

A water transfer printing process was used as schematically described above in FIGS. 1 A-1F.

(1) Either on a thermoplastic sheet or an aligner tray was selected as a substrate for water transfer printing; 2) the substrate was cleaned, primed and basecoated to receive the durable graphic; 3) the PVA hydrographic film with the graphic thereon was placed on standing water in a water bath; 4) activator was applied to dissolve the PVA film to release the graphic image on water; 5) the substrate was submerged in the water bath to transfer the graphic image to the prepared surface; and 6) the substrate with printed image was removed from the water bath, followed by air drying and clear coating. Example 1

FIG. 3 shows the graphic images on PETg sheets used in the water transfer printing process discussed above. A PETg disk with a graphic image was used to create an aligner tray as shown in FIG. 4. Example 2

FIG. 5 shows a water transfer graphic image on a prefabricated aligner tray produced via thermoforming.

Example 3 A blank P VA film was used to create hydrographic film where the graphic image can provide therapeutic benefits. An image layer including 2% by weight of the anti m i c rob i al/a ntibiofil m agent monolaurin (lauricidin) was applied to the PVA film. The image layer was hydrographically transferred to a PETg film and then transported through a Fusion UV conveyor belt equipped with a H-Bulb UV curing lamp (Haraeus Group, Hanau, DE) to sufficiently cure and solidify the printed ink (i.e. such that it felt hard to the touch, and could not be rubbed from the PETg surface).

The graphic image including 2% monolaurin (lauricidin) exhibited a 4-log reduction in s. mutans bacteria after 24 hr. The imaged PETg substrate was then thermoformed with a Biostar VI pressure molding/thermoforming machine (Scheu Dental) to shape a thermoplastic disc with 125 mm diameter into an orthodontic aligner tray per UTK-RDTP-11-300071.

Various embodiments of the invention have been described. These and other embodiments are within the scope of the following claims.

Claims

CLAIMS:

1. A method for making a dental appliance configured to position at least one tooth of a patient, the method comprising: depositing an image layer on a major surface of a water-soluble polymeric image carrier substrate; placing the water-soluble image carrier substrate in an aqueous liquid to at least partially dissolve the image carrier substrate; immersing into the aqueous liquid a substantially flat polymeric transfer substrate through the image layer such that the image layer transfers to a surface of the transfer substrate; removing the transfer substrate from the aqueous liquid with the image layer bonded to the surface thereof; and forming a plurality of cavities in the substantially flat transfer substrate to form a dental appliance comprising an arrangement of cavities configured to receive one or more teeth, wherein the image layer adheres to a surface of the dental appliance and forms a graphic image thereon.

2. The method of claim 1, wherein the water-soluble polymeric image carrier substrate comprises material chosen from polyvinyl alcohol (PVA), ethylene vinyl acetate, carboxymethyl cellulose, polyanionic cellulose, hydroxypropyl methylcellulose, N-(2-Hydroxypropyl)methacrylamide (HPMA), polyethylene oxide (PEO), polyethylene glycol (PEG), polyacrylic acid (PAA), polyacrylamides, polyvinylpyrrolidone (PVP), and mixtures and combinations thereof.

3. The method of claim 1 or 2, further comprising applying an activator composition to the image layer to form an activated image layer prior to transfer of the activated image layer to the surface of the polymeric film substrate.

4. The method of claims 1-3, wherein the surface of the transfer substrate comprises a surface treatment, and the image layer adheres to the primer layer.

5. The method of claims 1-4, further comprising at least partially drying or curing the image layer prior to placing the water-soluble image carrier substrate on the aqueous liquid.

6. The method of claims 1-5, further comprising at least partially drying the image layer on the surface of the transfer film substrate prior to the forming step.

7. The method of claims 1-6, further comprising applying a topcoat over at least a portion of the graphic image.

8. The method of claims 1-7, wherein the image layer comprises a biocompatible metal or metal oxide selected from the group consisting of copper, silver, zinc, silver oxide, copper oxide, gold oxide, stannous oxide, zinc oxide, magnesium oxide, titanium oxide, chromium oxide, and mixtures, alloys and combinations thereof.

9. The method of claim 8, wherein the image layer is deposited by physical deposition or sputtering.

10. The method of claims 1-7, wherein the image layer is transferred to the image carrier substrate from a release surface.

11. The method of claims 1-7, wherein the image layer is coated or printed on the image carrier substrate.

12. The method of claim 13, wherein the image layer comprises a hardenable ink composition, the hardenable ink composition comprising a therapeutic agent chosen from antimicrobial agents, antibiofilm agents, friction-reducing agents, anti-cavity agents, and mixtures and combinations thereof.

13. The method of claim 14, wherein the graphic image comprises a therapeutic agent chosen from anti-cavity agents and re-mineralizing agents, the anti-cavity agents and re-mineralizing agents chosen from calcium compounds, phosphorous compounds, fluoride compounds, and mixtures and combinations thereof.

14. The method of claims 1-13, wherein the image layer adhered to the transfer substrate is distorted relative to the graphic image on the dental appliance.

15. The method of claims 1-14, further comprising mapping the surface of the dental appliance such that selected locations on the image layer adhere to selected locations on the surface of the transfer substrate to form the graphic image on the dental appliance.

16. A method for applying a graphic image to a dental appliance, the method comprising: printing a hardenable ink composition on a major surface of a water-soluble polymeric image carrier substrate to form on the major surface of the image carrier substrate an image layer; placing the water-soluble polymeric image carrier substrate on a surface of an aqueous liquid to at least partially dissolve the image carrier substrate; immersing into the aqueous liquid a dental appliance through the image layer such that the image layer transfers to a surface of a dental appliance, wherein the dental appliance comprises a plurality of cavities configured to retain one or more teeth; removing the dental appliance transfer substrate from the aqueous liquid with the image layer bonded to the surface thereof such that the image layer adheres to a surface of the dental appliance and forms a graphic image thereon.

17. The method of claim 16, wherein the water-soluble polymeric image carrier substrate comprises material chosen from polyvinyl alcohol (PVA), ethylene vinyl acetate, carboxymethyl cellulose, polyanionic cellulose, hydroxypropyl methylcellulose, N-(2-Hydroxypropyl)methacrylamide (HPMA), polyethylene oxide (PEO), polyethylene glycol (PEG), polyacrylic acid (PAA), polyacrylamides, polyvinylpyrrolidone (PVP), and mixtures and combinations thereof.

18. The method of claim 16 or 17, wherein the image layer comprises a hardenable ink composition, the hardenable ink composition comprising a therapeutic agent chosen from antimicrobial agents, anti-biofilm agents, friction-reducing agents, anti-cavity agents, and mixtures and combinations thereof.

19. A method of forming a graphic image on a dental appliance, the method comprising: selecting a water-soluble polymeric transfer film article comprising an image layer on a major surface of a water-soluble polymeric transfer film; placing the water-soluble polymeric transfer film substrate in an aqueous liquid; dipping a substantially flat polymeric film transfer substrate through the image layer and into the aqueous liquid such that the image layer transfers to a surface of the flat polymeric film transfer substrate; removing the substantially flat polymeric film transfer substrate from the aqueous liquid with the image layer bonded to the surface thereof; and forming a plurality of cavities in the substantially flat polymeric film substrate to form a dental appliance comprising an arrangement of cavities configured to receive one or more teeth, wherein the image layer adheres to a surface of the dental appliance and forms the graphic image thereon.

20. The method of claim 19, wherein the water-soluble polymeric image carrier substrate comprises material chosen from polyvinyl alcohol (PVA), ethylene vinyl acetate, carboxymethyl cellulose, polyanionic cellulose, hydroxypropyl methylcellulose, N-(2-Hydroxypropyl)methacrylamide (HPMA), polyethylene oxide (PEO), polyethylene glycol (PEG), polyacrylic acid (PAA), polyacrylamides, polyvinylpyrrolidone (PVP), and mixtures and combinations thereof, and wherein the image layer comprises a hardenable ink composition, the hardenable ink composition comprising a therapeutic agent chosen from antimicrobial agents, anti-biofilm agents, friction-reducing agents, anti-cavity agents, and mixtures and combinations thereof.