Systems and methods for orthodontic devices

Embodiments presented herein provide apparatus and methods for forming and coupling an attachment device onto one or more teeth. A system comprises a template including a shell having a cavity defining a shape that is operable to receive one or more teeth. The template comprises an aperture at one or more predetermined locations. The aperture defines an aperture perimeter. The system further comprises one or more attachment molds. Each attachment mold comprises a mold bore therethrough. The attachment mold further includes a mold perimeter surface that defines a predetermined shape, wherein each of the aperture perimeters being operable to receive and cooperate with the mold perimeter surface of one of the attachment molds. Each mold bore being operable for providing a mold for forming an attachment device coupled to a tooth of a desired shape and orientation from curable material that may be disposed within the mold bore.

FIELD

The present invention is related generally to the field of orthodontics. More particularly, the present invention involves systems and methods that enable accurate formation and placement of composite attachments on a dental surface for a patient undergoing orthodontic treatment.

BACKGROUND

Orthodontic treatment involves the repositioning of misaligned teeth and improving bite configurations for improved dental function and cosmetic appearance. Repositioning teeth may be accomplished by applying controlled forces to the teeth over an extended period of time. A number of systems and techniques are known for applying the required forces to the teeth.

One known method for applying forces to the teeth is by the use of elastic positioning appliances as described by Chishti et al. in U.S. Pat. No. 5,975,893. Such positioning appliances comprise a thin shell of elastic material that generally conforms to a patient's teeth but is slightly out of alignment with the initial tooth position. Placement of the positioning appliance over the teeth applies controlled forces to the teeth to gradually move the teeth into a new position. Repetition of this process with successive positioning appliances comprising new teeth positions eventually moves the teeth through a series of intermediate positions to a final desired position.

When the positioning appliance is placed over a prescribed group of teeth, one or more of the teeth may provide an anchor for holding the appliance in place while the stiffness of the appliance imparts a positioning force against at least a portion of the target teeth.

The anchoring and repositioning abilities of positioning appliances are dependent at least in part on the physical features and positions of the patient's teeth, previous dental work, and the like. Among other things, these physical features may not be optimally suitable for providing an optimal force bearing surface for anchoring or applying positioning forces to the teeth by the positioning appliance. For example, but not limited thereto, positioning appliances may have difficulty applying certain forces to individual teeth, such as extrusive forces (e.g., pulling or raising a tooth relative to the jaw).

Attempts to augment the force transfer between the positioning appliance and the teeth have been attempted, such as those described by Phan et al. in U.S. Pat. No. 7,125,248. Phan et al. describes the use of attachment devices that are bonded to one or more teeth or other dental feature so as to provide an enhanced surface upon which the positioning appliance may bear. Phan et al. describes a method of forming and bonding the attachment device to the teeth with the use of a mold. The mold is substantially in the form of the positioning appliance, which substantially conforms to the teeth, but has one or more negative impressions having a shape that is complementary to the desired attachment device. Malleable polymerizing material is placed in the negative impression and the mold slidingly received over the teeth. The polymerizing material is cured such that when the mold is removed from the teeth, the now polymerized material forms the attachment device that, if successful, is bonded to the tooth. This method is referred herein as the mold-in-place approach.

In practice, the mold-in-place approach as provided by Phan et al. has a number of shortcomings. One shortcoming, among others, is that a precise amount of the polymerizing material must be disposed within the respective negative impression otherwise the negative impression may be underfilled or overfilled. An underfilled negative impression may lead to, among other things, an underdeveloped or malformed attachment device that is not suitable for the intended purpose. Further, an underfilled negative impression may lead to, among other things, the polymerizing material making only partial or insufficient contact with the tooth surface thereby resulting in an attachment device that is partially or insufficiently bonded to the tooth. Ensuring full contact between the polymerizing material and the tooth surface is further complicated by the necessity of using a very viscous polymerizing material. The polymerizing material must be very viscous so that, among other things, the polymerizing material stays substantially within the negative impression during handling of the mold and in placement on the teeth. Being very viscous or putty-like, the polymerizing material may not flow towards the tooth surface and make full contact therewith prior to curing resulting in a poorly or not bonded attachment device.

An overfilled negative impression may lead to, among other things, an ill-fitting, distorted mold. An overfilled mold may, among other things, not seat properly on the tooth surface so as to not position the polymerizing material at the intended location and/or may form a malformed attachment device after cure. The mold may have to be forcibly held in place on the teeth to ensure that it is properly seated thereon during the curing process.

An overfilled negative impression may lead to, among other things, flashing. Flashing is excess polymerizing material that may deposit on unintended tooth surfaces and/or beyond the prescribed footprint of the attachment device. The excess material may be unintentionally deposited on the tooth surface when the mold is slidingly received onto the teeth. The excess material may extrude away from the negative impression when pressure is exerted onto the mold during placement and cure of the polymerizing material. Flashing must be removed to allow for proper placement of the positioning appliance onto the teeth. Flashing has the potential to cause, among other things, the positioning appliance to not seat properly on the teeth and may cause unintentional forces on the teeth resulting in improper repositioning. Removing flashing is labor and time intensive and may lead to damage to the resulting attachment device and/or undesirable modification of the underlying tooth surface to which it is attached.

A precisely formed attachment device is crucial for optimal performance of the positioning appliance. The shape of the positioning appliance is designed taking into account the precise position and shape of any attachment devices that may be provided. A malformed or misplaced attachment device may lead to, among other things, a malfitting positioning appliance that may result in non-prescribed or inefficient expressions of intended forces acting on one or more teeth resulting in unpredictable and undesired repositioning of the teeth.

The consequences of improperly formed attachment devices may lead to an interruption in the proposed intended sequence of progressive positioning appliances. Positioning appliances are created and supplied by the manufacturer as a set with the expectation that the attachment devices are properly formed. In many cases, the imprecise placement and formation of the attachment devices results in, among other things, inappropriate repositioning of the teeth prolonging the treatment, and requiring the manufacture of additional positioning appliances to reposition or fine-tune the repositioning of the teeth which increases the cost of materials and patient and doctor time.

It would therefore be desirable to provide apparatus and methods for forming and positioning attachment devices that address one or more of these shortcomings.

SUMMARY

Embodiments of the present invention provide apparatus and methods for simultaneously forming and coupling an attachment device onto one or more teeth. In accordance with an embodiment, a system is provided that comprises a template including a shell having a cavity defining a shape that is operable to receive one or more teeth. The template includes a template inner surface and a template outer surface opposite the template inner surface. The template further comprises an aperture at one or more predetermined locations that extends from the template inner surface to the template outer surface therethrough. The aperture defines an aperture perimeter having a predetermined shape. The system further comprises one or more attachment molds. Each attachment mold comprises a mold first surface and a mold second surface opposite the mold first surface. The attachment mold includes a mold bore having a bore surface extending from the mold first surface to the mold second surface therethrough. The attachment mold further includes a mold perimeter surface that defines a predetermined shape, wherein each of the aperture perimeters being operable to receive and cooperate with the mold perimeter surface of one of the attachment molds. Each mold bore is operable for providing a mold for forming an attachment device of a desired shape and orientation from curable material that couples to the tooth that may be disposed within the mold bore.

In accordance with an embodiment, a method for simultaneously forming and coupling an attachment device on one or more teeth is provided. The method comprises providing a template including a prescribed number and placement of apertures; disposing the template over the teeth exposing tooth surface through each aperture; disposing an attachment mold through each respective aperture, wherein the attachment mold includes a mold bore suitable for providing a mold for forming an attachment device of the desired shape from curable material; removably coupling the mold first surface of the attachment mold to the exposed tooth surface with the mold bore defining target tooth surface; preparing the target tooth surface to receive curable material; disposing curable material within the mold bore and in contact with the target tooth surface; curing the curable material to a hardened state to form an attachment device that is coupled to the target tooth surface; removing the template; and removing the attachment mold from the attachment device.

DETAILED DESCRIPTION

In the following description, embodiments of apparatus and methods will be disclosed. For purposes of explanation, specific numbers, materials, and/or configurations are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to those skilled in the art that the embodiments may be practiced without one or more of the specific details, or with other approaches, materials, components, etc. In other instances, well-known structures, materials, and/or operations are not shown and/or described in detail to avoid obscuring the embodiments. Accordingly, in some instances, features are omitted and/or simplified in order to not obscure the disclosed embodiments. Furthermore, it is understood that the embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of claimed subject matter. Thus, the appearances of the phrase “in one embodiment” or “an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in one or more embodiments.

Reference will now be made to embodiments illustrated in the drawings and specific language which will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the illustrated embodiments and further applications of the principles of the invention, as would normally occur to one skilled in the art to which the invention relates, are also within the scope of the invention.

For the purposes of the subject matter disclosed herein, reference to a positioning appliance refers to an appliance, such as, but not limited to, a polymeric shell, having cavities with geometries shaped to receive and resiliently reposition from one position to a successive position of one or more teeth, such as, but not limited to, appliances provided in Chishti et al., U.S. Pat. No. 5,975,893.

For the purposes of the subject matter disclosed herein, reference to an attachment device refers to an element having predetermined dimensions which is coupled to a tooth or restored tooth surface and operable to be engaged by a positioning appliance to enhance the ability of the positioning appliance to exert a controlled orthodontic force on one or more teeth and/or to increase the retention of the positioning appliance on the teeth.

For the purposes of the subject matter disclosed herein, reference to flash and flashing refers to excess curable material, such as, but not limited to, polymerizing material, that may be deposited on the tooth surface during the molding of the attachment device.

FIG. 1is a perspective view of a system100for simultaneously forming and coupling attachment devices onto one or more teeth150, in accordance with an embodiment.FIG. 2is a perspective view of an attachment device160coupled to a tooth150, in accordance with an embodiment. InFIG. 1, the system100comprises a template200and one or more attachment molds300. The template200comprises a shell having a cavity202with a shape operable to receive one or more teeth150. The template200defines a template inner surface204and a template outer surface206opposite the template inner surface204. The template200is operable to removably engage the teeth150.

At one or more predetermined locations the template200comprises an aperture210that extends from the template inner surface204to the template outer surface206therethrough. The aperture210defines an aperture perimeter212that is operable to receive and cooperate with the mold perimeter surface320of one of the attachment molds300as will be described below.

The predetermined location of each of the apertures210is determined by the prescribed location of a desired attachment device on a tooth surface. The location of the desired attachment device is determined and prescribed, at least in part, by the dentist in accordance with a treatment plan. As will be discussed below, each aperture210is operable to receive and cooperate with an attachment mold300therein such that the attachment device may be formed and located at the prescribed location and orientation on a tooth surface. Discussion of the process for determining the prescribed location of the desired attachment device is provided below.

The template200may further comprise handling structures and surfaces to assist in the placement and removal of the template200from the teeth150, in accordance with another embodiment. The template200may incorporate frangible portions to allow for the tearing away or dividing of the template200into pieces to assist in removing the template from the teeth150, in accordance with another embodiment.

The template200may, but not necessarily, fit over all teeth150present in the upper or lower jaw. In accordance with an embodiment, the template200is operable to fit over one or more teeth150, one or more of which is to receive an attachment device160. In accordance with an embodiment, the template200is operable to fit over one tooth150which is to receive an attachment device160.

The teeth150adjacent to those to receive an attachment device160may be used to provide a base or anchor region for holding the template200in place as it locates respective apertures210in the desired locations of teeth150to receive an attachment device160. In accordance with an embodiment, the template inner surface204sufficiently conforms to the contours of the teeth150such that the template200snaps into place and is removably coupled to the teeth150. In another embodiment, the template200is manually held in place during placement onto the teeth150and cure of the curable material.

In accordance with an embodiment, the template200comprises a thin polymeric material. The template200may comprise any suitable material and be fabricated using any suitable process. In accordance with an embodiment, the template200ofFIG. 1may be formed from a thin sheet of a suitable elastomeric polymer, such as Tru-Tain thermal forming dental material, Tru-Tain Plastics, Rochester, Minn. 55902, which may be formed over a replica of the teeth. In other embodiments, the template200may be formed using additive manufacturing technology, also known as rapid prototyping, in which the template200is produced from a base material directly from computer aided design software. It is appreciated that many fabrication processes may be suitable for fabricating the template200and not limited to the examples presented herein.

FIG. 3is a perspective view of an attachment mold300, in accordance with an embodiment.FIG. 4is a cross-sectional view of the attachment mold300ofFIG. 3along cut-line4-4. The attachment mold300comprises a mold first surface304and a mold second surface306opposite the mold first surface304. The attachment mold300defines a mold bore310having a bore surface312extending from the mold first surface304to the mold second surface306therethrough. The attachment mold300further defines a mold perimeter surface320that defines a predetermined shape as will be explained below.

In accordance with an embodiment, the attachment mold300comprises an elastic material operable to be readily stretched and peeled from the tooth150and attachment device160, shown inFIG. 2, after the curing of the curable material therein. Being elastic means that the attachment mold300may be worked off from the attachment device160within it, and/or the attachment mold300may be cut or torn to be removed from the attachment device160.

The attachment mold300further comprises an adhesive layer324on the mold first surface304. The adhesive layer324is operable for removably coupling the attachment mold300to a tooth surface154.

FIG. 5is a cross-sectional view along cut-line5-5shown inFIG. 1of an embodiment of a system100as disposed onto a tooth150with the addition of curable material170and the cover plate180, in accordance with an embodiment. In accordance with an embodiment, the adhesive layer324provides a means to conform the mold first surface304to an irregular tooth surface154. The adhesive layer324may allow for conformance of the mold first surface304to the irregular tooth surface154by one or more of any suitable means, such as, but not limited, the elastic properties of the adhesive layer324, pressure-sensitivity of the adhesive layer324, a foam matrix within the adhesive layer324, and/or in combination with the resiliency and elasticity of the attachment mold300, among many others.

In accordance with an embodiment, the adhesive layer324provides a sealing engagement with the tooth surface154so as to resist the infiltration of saliva or other contaminants onto the tooth surface154exposed by the mold bore310. In accordance with an embodiment, the adhesive layer324resists the migration between the mold first surface304and the tooth surface154of curable material170that is disposed within the mold bore310prior to curing the curable material170forming the attachment device160that is coupled to the tooth surface154. Further, in accordance with an embodiment, the adhesive layer324resists the migration between the mold first surface304and the tooth surface154of tooth surface preparation materials and solutions, such as, but not limited to, etching and cleaning solutions.

In accordance with an embodiment, the adhesive layer324comprises a material which is opaque to those light frequencies associated with curing curable material which is curable by exposure to light-curing radiation. The opaque adhesive layer324is operable to shadow or block light-curing radiation from illuminating between the mold first surface304and the tooth surface154and therefore resists the curing of any curable material170that may unintentionally migrate between the mold first surface304and the tooth surface154resulting in flash. Any uncured curable material170left on the tooth surface154after removal of the attachment mold300may be removed relatively easily as compared with flash that is cured.

In accordance with an embodiment, the adhesive layer324comprises a material which is operable to removably couple to the tooth surface154to the extent that it restricts liquids and gels from penetrating between it and the tooth surface154. The adhesive layer324is operable to be peeled off or otherwise removed from the tooth surface154after use without altering or damaging the tooth surface154or contour thereof.

In accordance with an embodiment, the adhesive layer324is operable to resist decoupling of the attachment mold300from the tooth surface154which may be facilitated by any surface preparation of the exposed tooth surface154, such as, but not limited to, by cleaning, etching, and drying, that may occur prior to the deposition of the curable material170into the mold bore310. This provides, among other things, for a very limited area of exposure of the tooth surface154to chemical and mechanical surface preparation that may affect the tooth surface154to only that location associated with an attachment device.

In accordance with another embodiment, an opaque layer322comprising a material which is opaque to those light frequencies associated with curable material which is curable by exposure to light-curing radiation is disposed between the mold first surface304and the adhesive layer324, as shown inFIG. 4. The opaque layer322is operable to shadow or block light-curing radiation from illuminating between the mold first surface304and the tooth surface154and therefore resists the curing of any curable material170that may unintentionally migrate between the mold first surface304and the tooth surface154. Any uncured curable material left on the tooth surface154after removal of the attachment mold300may be removed relatively easily as compared with flash that is cured.

It is appreciated that the attachment mold300may itself comprise an opaque material operable to block the light-curing radiation from illuminating between the mold first surface304and the tooth surface154. But it is also appreciated that the illumination of light-curable material170may be assisted wherein the attachment mold300comprises a transparent material operable to allow light-curing radiation to illuminate the curable material170within the mold bore310from the top as well as from the sides of the attachment mold300.

FIG. 6is a perspective view of a cover plate180including a plate aperture182in accordance with an embodiment. The cover plate180comprises a plate inner surface184and a plate outer surface186opposite the plate inner surface184. The plate aperture182extends from the plate inner surface184to the plate outer surface186therethrough. In accordance with an embodiment, the cover plate180is substantially flat. The cover plate180is operable to cover the mold bore310and the mold second surface306. Wherein a light-curable curable material is used to form an attachment device, the cover plate180may comprise a material that is translucent to light-curing radiation.

The cover plate180is operable for allowing for the compression of curable material170within the mold bore310to affect intimate contact between the curable material170and the tooth surface154and minimize voids within the curable material170. The plate aperture182is operable for allowing excess curable material170to extrude from the mold bore310under pressure created as the cover plate180is pressed against the mold second surface306and curable material170, such as shown inFIG. 5.

It is appreciated that in another embodiment, the cover plate180may be provided without a plate aperture182, wherein any excess curable material170may extrude around the edges of the cover plate180under pressure created as the cover plate180is pressed against the mold second surface306and curable material170.

In accordance with an embodiment, each of the attachment molds300has one of a predetermined unique shape of the mold perimeter surface320that is complementary with a predetermined unique shape of a corresponding aperture perimeter212of the aperture210in the template200. The unique shape of the mold perimeter surface320, among other things, prevents the use of an attachment mold300that was not intended for the attempted location on the template200. An attachment mold300that is mismatched to an aperture210will not fit properly within the aperture210preventing advancement of the attachment mold300to the tooth surface154. The ill-fitting correspondence between the attachment mold300and the aperture210alerts the practitioner that an incorrect attachment mold300is being attempted at placement.

In accordance with an embodiment, a particular unique size and/or shape of the mold perimeter surface320may be associated with a particular unique size and/or shape of an attachment mold bore310suitable for forming an attachment device160of a unique size and/or shape.FIGS. 7A-7Care top views of embodiments of various attachment molds300a-cby way of example and not limited thereto. InFIG. 7a, a first attachment mold300acomprises a particular shape of a first mold perimeter surface320aand a first mold bore310ahaving a rectangular cross-section that is operable to produce an attachment device in the form of a post having a rectangular cross-section. InFIG. 7b, a second attachment mold300bcomprises a second mold perimeter surface320bhaving a triangular-shaped cross-section and a second mold bore310bhaving a square cross-section that is operable to produce an attachment device in the form of a post having a square cross-section. InFIG. 7c, a third attachment mold300ccomprises a third mold perimeter surface320chaving an octagonal-shaped cross-section and a third mold bore310chaving a triangular cross-section that is operable to produce an attachment device in the form of a post having a triangular cross-section. Again, the uniqueness of the size and/or shape of the mold parameter surface320having a particular size and/or shape of mold bore310, among other things, alerts the practitioner that a correct or incorrect attachment mold300is being attempted at placement at a particular template aperture210t.

FIG. 8is a partial side view of a system100showing teeth150, a template200, and attachment molds300coupled to the teeth150, in accordance with an embodiment. The template200has a first aperture210awith a first aperture perimeter212a, a second aperture210bhaving a second aperture perimeter212b, and a third aperture210chaving a first aperture perimeter212a. The first aperture210aand the third aperture210chave the same aperture perimeter212abut at different orientations to the respective tooth surface. The first aperture210aand the third aperture210care operable to receive a first attachment mold300dhaving a fourth mold perimeter surface320dand a fourth mold bore310dexposing a portion of the tooth surface154. The second aperture210bis operable to receive a fifth attachment mold300ehaving a fifth mold perimeter surface320eand a fifth mold bore310eexposing a portion of the tooth surface154.

By way of example, the unique aperture perimeter212aprovides, among other things, a keyway232dthat is operable to cooperate with the corresponding mold perimeter surface320including keys332d, ensuring, among other things, the use of the proper mold300dand/or the proper orientation of the mold300dwithin the aperture210a. Where the attachment mold300dmay be received within the aperture210ain only a predetermined orientation assures that the attachment mold300dis correctly orientated to the tooth surface154substantially where prescribed.

By way of example, but not limited thereto, a system100is described as suitable for a particular patient. Measurement data of a patient's teeth is collected. Measurement data may be collected by one of any suitable processes, such as, but not limited to, creating a physical impression of the patient's teeth150and creating a virtual impression of the patient's teeth150via a process such as, but not limited to, computer scanning. An impression, or a virtual, computer-generated “impression”, of the patient's teeth150is created. A computer model of the patient's teeth150is created based on the measurement data using processes known in the art, such as those described in Chishti et al., U.S. Pat. No. 5,975,893, incorporated herein by reference.

The design of the template200is facilitated by computer-aided design methodologies known in the art, such as those provided in Chishti et al. in U.S. Pat. No. 5,975,893. A computer model of the patient's teeth and the desired result of the positions of the teeth is analyzed to determine whether the use of attachment devices160would aid in the desired movement of the teeth150from a first position to a second position. The use of attachment devices160of particular geometries may provide movement of the teeth150that is more efficient or along a different path than achievable based on relying entirely on force bearing natural tooth surfaces or contours of the teeth150. The location and shape of attachment devices160at specific locations of the teeth150, as well as which specific shape of attachment device160that is appropriate for the intended purpose, are determined.

A template200is created that is operable to engage and removably couple onto one or more of the teeth150in substantially the same manner as a positioning appliance as described in Chishti et al. The template200is provided with apertures210corresponding to those locations that analysis had determined an attachment device160is to be provided on the teeth150. Each aperture210defines a unique shape of the aperture perimeter212, in accordance with an embodiment, or one of a finite set of shapes of aperture perimeters212in accordance with another embodiment.

Attachment molds300are provided, one of each having a unique shape of the mold perimeter surface320corresponding to one of each aperture210having a unique shape of the aperture perimeter212provided in the template200. Each of the attachment molds300defines a mold bore310suitable for providing a mold for forming an attachment device160of the desired shape from curable material170suitable for a particular purpose. Since each aperture210and corresponding attachment mold300has one of a unique shape of aperture perimeter212and mold perimeter surface320, respectively, that are complementary to each other such that a respective attachment mold300may be received within a corresponding aperture210, a practitioner cannot place an incorrect attachment mold300in a given aperture210.

It is understood that the modularity of the association of apertures210and attachment molds300allows for many combinations wherein unique and/or similar attachment molds300may be used in a given aperture210. By way of example but not limited there to, a plurality of attachment molds300having the same shape of mold perimeter surface320and same shape of the mold bore310may be used interchangeably within multiple apertures210to provide an attachment device160of a given same shape. The orientation of the attachment device160may be determined by the orientation of the aperture210relative to the tooth surface154that is exposed by the aperture210, such as shown inFIG. 8.

In accordance with embodiments of methods, the template200is placed over the teeth150. Each aperture210allows access to the tooth surface154at the locations wherein an attachment device160is to be formed and coupled to the tooth surface154. A plurality of attachments molds300are provided, each having one of a unique shape of mold perimeter surface320d,ecorresponding to each of the corresponding apertures210a-ceach having one of a corresponding shape of the aperture perimeter212a,b.An attachment mold300is coupled to the tooth surface154through the aperture210a-c. The tooth surface154that is exposed by the mold bore310d,eis prepared to receive an attachment device160.

In accordance with an embodiment, each of the attachment molds300has one of a predetermined unique cross-section of the mold bore310so as to produce an attachment device160having a unique cross-section. In accordance with other embodiments, multiple attachment molds300having one of a finite set of unique cross-sections of mold bores310is provided.

The bore310of the attachment mold300determines, in part, the resulting shape of the attachment device160. The shape of the bore310may be any suitable shape that is operable to be molded. By way of example, the bore310may have a square lateral cross-section that results in an attachment device160having a square lateral cross-section having a height substantially corresponding to the distance between the mold first surface304and the mold second surface306.

The shape of the attachment device160is predetermined based, in part, on the prescribed force desired for that specific location in order to transmit force generated by the dental positioning appliance to the teeth150.

In accordance with an embodiment, the attachment devices160may be relatively small, for example, but not limited to, 2 mm wide by 4 mm long by 2 mm high, as compared with conventional dental brackets. The prescribed size and shape of the attachment devices160may vary in order to provide ideal function as prescribed during treatment plan development.

The attachment devices160may be coupled at specific locations throughout the dentition where appropriate and this may only be required at one or a few locations. The attachment devices160may be coupled to any surface of the teeth150, including lingual surfaces.

In accordance with embodiments, the attachment devices160may provide the function of one or more of, but not limited to, an anchor for the removable coupling of the positioning appliance to the teeth, and as a point of leverage for the positioning appliance to exert a prescribed force onto the teeth.

Again,FIG. 5is a cross-sectional view of an embodiment of the template200and the attachment mold300operable for forming and coupling one or more attachment devices onto one or more teeth150. The template200is disposed onto and is in snug removable engagement with the teeth150. An aperture120exposes a portion of the tooth surface154onto which an attachment device is to be formed and coupled to the tooth surface154. An attachment mold300is disposed within the aperture120with the adhesive layer324coupling the attachment mold300to the tooth surface154. The mold bore310defines a portion of the tooth surface154as the target tooth surface154a. The target tooth surface154ais prepared to receive the curable material170. Curable material170is disposed within the mold bore310and in contact with the target tooth surface154a. A cover plate180is disposed over the mold second surface306with any excess curable material172allowed to extrude from the plate inner surface184to the plate outer surface186through the plate aperture182. Excess curable material172which has extruded from the plate aperture182and/or from around the edge of the cover plate180may be removed prior to curing the curable material170.

The curable material170is cured into a hardened state forming the attachment device160that is coupled to the tooth surface154.FIG. 9is a side view of the attachment device160as coupled to the tooth150, in accordance with an embodiment. The attachment mold300is removed from the attachment device160. The template200may be removed intact and reused for forming subsequent attachment devices160or may be divided into various pieces so as to be more easily removed from the teeth150. Any remaining flash of cured curable material172on the top surface of the attachment device160, such as that from within the plate aperture182, is relatively easily removed, such as, but not limited to, by mechanical grinding and the like. Any resulting flash of uncured curable material172that may be present around the base of the attachment device160from between the mold first surface304and the tooth surface154may be removed by wiping and/or washing.

It is appreciated that the attachment mold may comprise a mold bore having a shape suitable to a particular purpose.FIGS. 10A and 10Bare cross-sectional and top views, respectively, of an attachment mold1300in accordance with another embodiment. The attachment mold1300comprises a mold first surface304and a mold second surface306opposite the mold first surface304. The attachment mold1300defines a mold bore1310having a bore surface1312extending from the mold first surface304to the mold second surface306therethrough. The mold bore1310comprises a first portion1314having a first diameter and a second portion1316having a second diameter that is larger than the first portion1314. The mold bore1310has a compound circular cross-section that is operable to produce an attachment device in the form of a cylindrical post having two diameters. The attachment mold1300further comprises an opaque layer322and an adhesive layer324on the mold first surface304. The adhesive layer324is operable for removably coupling the attachment mold1300to a tooth surface154.

FIG. 11is a side view of a compound attachment device1160that may be formed by the attachment mold1300of FIGS.10A,B. The compound attachment device1160comprises a top1164that is coupled to the tooth150by a shaft1162having a reduced diameter than that of the top1164. The mold bore1310, as shown in FIGS.10A,B, is operable to accept curable material therein so as to simultaneously form the top1164and the shaft1162of the attachment device1160that is coupled to the tooth150when cured.

The compound attachment device1160may or may not be used in association with positioning appliances. The compound attachment device1160may be particularly suitable for providing an anchor or an engagement for other dental devices, such as, but not limited to, orthodontic wires and elastic bands.

FIG. 12is a flow chart of a method in accordance with an embodiment. A template comprising a prescribed number and placement of apertures is provided and placed over the teeth exposing tooth surface through each aperture1202. A predetermined attachment mold is provided and received within each respective aperture and removably coupled to the tooth surface, the mold bore defining target tooth surface1204. The target tooth surface is suitably prepared to receive curable material1206, such as, but not limited to, cleaned, etched, rinsed, dried, and treated with bonding agent. Curable material is disposed within the mold bore of the attachment mold and in contact with the target tooth surface1208. In an embodiment, the curable material is made level with the mold second surface of the attachment mold1209. In accordance with another embodiment, a cover plate with a plate aperture is disposed on the mold second surface and over the mold bore extruding any excess curable material through the plate aperture, with any excess curable material being removed from the cover plate1210. The curable material is cured to a hardened state to form an attachment device that is coupled to the target tooth surface1212. The attachment mold is removed from the attachment device and the template1214. Additional attachment devices are formed by repeating the process with the other predetermined attachment molds received within respective apertures1217. The template is removed from the teeth1216.

In accordance with another embodiment, the method ofFIG. 12further comprises preparing the surface of the teeth to couple with the adhesive on the mold first surface before placement of the template. The surface of the teeth is prepared to provide a suitable coupling surface for the adhesive by, such as, but not limited to, cleaning, removal of tarter and plaque, drying, and treating with a bonding agent. Substantially the same preparation activities may be suitable for preparing the target tooth surface for receiving curable material to affect a good coupling between the tooth surface and the resulting attachment device.

In accordance with embodiments, the template200may comprise means, such as, but not limited to, frangible portions265as shown inFIG. 8, to provide for easily breaking apart, particularly at the apertures, so as to facilitate removal of the template from the teeth and attachment devices.

In accordance with embodiments, the attachment mold300may comprise means, such as, but not limited to, frangible portions and elastic properties, to provide for easily breaking apart, peeling away, or elastically deforming, so as to facilitate removal of the attachment mold300from the attachment device160.

The curable material may be cured by any process suitable for the particular material. By way of example, but not limited thereto, light-curable composite resin used for dental applications may be suitable for the particular purpose. Many curable materials are known in the art and it is appreciated that the materials are cured in the manner that the particular material is formulated to be cured.

In accordance with another embodiment of a method, the attachment molds300are disposed within respective apertures210and removably coupled to the template200prior to the placement of the template200onto the teeth150. The attachment molds300are held within the respective aperture210and recessed from the template inner surface204, and therefore recessed from the tooth surface154upon placement of the template200onto the teeth150. Once the template200is seated onto the teeth150, the attachment molds300are released from the template200and pressed against the tooth surface154.

A single placement system for forming and coupling an attachment device onto a tooth is provided in accordance with another embodiment. The single placement system is substantially the same as the various embodiments of system100discussed above but without the template200. The single placement system may be particularly useful where precise placement of an attachment device is not critical to the use of the attachment device. By way of example, but not limited thereto, the attachment device1160ofFIG. 11may be particularly useful to provide a feature to hook an elastic band to, such may be used to erupt teeth or to grossly rotate them. Precise location and orientation of the attachment device may not be critical to these uses. In contrast to bonding a preformed attachment device to the tooth, an attachment device may be simultaneously formed and coupled to the tooth with the single placement system.

The single placement system comprises one or more attachment molds. The attachment molds are substantially the same as the embodiments of attachment mold300ofFIG. 4, the attachment molds300d,300eofFIG. 8, and the attachment mold1300ofFIG. 10A. The uniqueness of the mold perimeter, such as the key332dshown inFIG. 8, is not critical for the single placement system since a template is not used. The attachment mold further comprises an opaque layer322and an adhesive layer324on the mold first surface304such as provided inFIG. 4. The adhesive layer324is operable for removably coupling the attachment mold300to a tooth surface154.

A method for forming and coupling an attachment device onto a tooth using the single placement system is substantially the same as the method for using system100as provided inFIG. 12, but without the use of the template. In accordance with an embodiment, a predetermined attachment mold is removably coupled to the tooth surface, with the mold bore defining target tooth surface. The mold first surface of each attachment mold is removably coupled to the exposed tooth surface with the mold bore defining target tooth surface through each mold bore. The target tooth surface is suitably prepared to receive curable material, such as, but not limited to, cleaned, etched, rinsed, dried, and treated with bonding agent. Curable material is disposed within the mold bore of the attachment mold and in contact with the target tooth surface. In an embodiment, the curable material is made level with the mold second surface of the attachment mold. In accordance with another embodiment, a cover plate with a plate aperture is disposed on the mold second surface and over the mold bore extruding any excess curable material through the plate aperture, with any excess curable material being removed from the cover plate. The curable material is cured to a hardened state to form an attachment device. The attachment mold is removed from the attachment device. Additional attachment devices may be formed by repeating the process.

In accordance with another embodiment, the method further comprises preparing the surface of the tooth to couple with the adhesive on the mold first surface before placement of the mold onto the tooth. The surface of the tooth is prepared to provide a suitable coupling surface for the adhesive by, such as, but not limited to, cleaning, removal of tarter and plaque, drying, and treating with a bonding agent. Substantially the same preparation activities may be suitable for preparing the target tooth surface for receiving curable material to affect a good coupling between the tooth surface and the resulting attachment device.

The attachment devices160in combination with removable dental positioning appliances provide the patient with the benefits of removable appliances while enhancing the ability of those appliances to extrude, rotate, and otherwise manipulate teeth as is done with conventional braces. Embodiments provided herein provide a system that enables precise placement of an attachment device on a dental surface for a patient undergoing orthodontic repositioning.

Embodiments provided herein are directed to simultaneously forming and coupling attachment devices to dental surfaces suitable for cooperative engagement with positioning appliances. The cooperative engagement may be, but not limited to, assist in the retention of the positioning appliance on the teeth and for the more efficient transmission of force(s) from the positioning appliance to the teeth. Embodiments herein allow for, among other things, the accurate placement of the attachment devices, the prevention of flashing of the curable material, the precise dimensionality of the attachment devices, the use of curable material having desired viscosities or other material properties that are not dependent on the handling concerns of the template, and allowing the serial processing of forming multiple attachments, among other things.