FIELD OF THE INVENTION

[0001] The inventive subject matter relates to dental appliances or retainers and related methods employing a smart material including a memory shape polymer to protect soft tissue of the oral cavity, particularly the gingiva, from dental treatment agents such as whitening peroxides.

BACKGROUND

[0002] Dental agents applied to teeth may cause untoward side effects particularly irritation and sores in the soft tissue of the mouth and gingiva. Some oral care treatments and dental appliances use bleaching agents, including carbamide peroxide, for the purpose of whitening teeth, removal of plaque or bacteria, or conducting other oral hygiene procedures. For example, teeth whitening can be accomplished by applying a whitening gel, varnish, dentrifice, or other oral care product onto the teeth. Some teeth whitening and other oral care products are typically applied by filling a dental "tray" containing the treatment agent. Often, the whitening agent is activated or enhanced by simultaneous application of light of a specific wavelength and intensity. For the treatment to be effective, the light intensity needs to be sufficiently high. One such procedure is a whitening treatment such as, for example, available under the trade name Philips Zoom system, employing 22 - 24 % carbamide peroxide followed by four fifteen minute treatments with blue light. U.S. Patent No. 7,086,862 is drawn toward such a known procedure. Another known tooth whitening system, utilizing a dental varnish composition, is described in U.S. Patent No. 10,307,348. Unfortunately, however, certain treatment agents may irritate the soft tissue, especially gingiva surrounding the teeth that come into contact with, and may even be immersed in, a treatment agent applied by conventional dental appliances.

[0003] In order to avoid causing irritation and developing sores in the gingival tissue surrounding the dentition undergoing whitening, it is important to shield teeth from potential caustic and untoward side effects of whitening agents, particularly carbamide peroxide. Conventional attempts to allay irritants and soreness to soft tissue especially gingiva surrounding the teeth and treatment area have employed a protective layer such as a silicone gel applied upon gingival tissue surrounding the teeth. The protective layer may be applied prior to placement of a dental tray, lip retractor or tongue protector. However, multiple drawbacks limit the efficacy of conventional protective layer compositions and methods. For example, the force applied against the dental arch surfaces when positioning a dental tray may push back the silicone gel thereby exposing gingiva above teeth being treated. Moreover, conventional dental trays typically lack a seal with a protective layer such as silicone gel, and thus permit a whitening agent or other dental treatment including, for example, carbamide peroxide, to permeate or leak onto surrounding soft tissue, including gingiva, surrounding the teeth being treated.

[0004] Conventional dental techniques also employ bulky lip or cheek retractors to hold soft tissue away from the soft tissues surrounding the portion of the teeth and mouth being treated. As shown in FIGS. 1A, IB and 1C, insertion and stabilization of such conventional dental retractors typically entails the three steps Illustrated is labor intensive and time consuming. First, opposing edges of a lip retractor are inserted beneath the upper and lower lips. Second, a tongue retractor is inserted against the patient's tongue. Third, a silicon layer is applied along the gum line adjacent to the patient's teeth.

[0005] Unfortunately, however, significant drawbacks and disadvantages associated with such conventional techniques persist. Conventional devices and procedures properly positioned during a dental treatment entails procedures that are time consuming, labor intensive, cumbersome, non-ergonomic and cause discomfort detracting from the dental care practitioner and patient experience. The configuration and constituent materials of such existing lip and tongue retractors provide limited pliability and therefore lack ready adaptability to a patient's dentition and mouth. The pressure exerted against soft tissue of the mouth and gingiva, together with the discomfort of having an open jaw for an extended time, detracts from the patient experience and may be stressful and/or painful for the patient. In addition to being time consuming, the implementation of conventional procedures entails awkward positioning and/or requires significant space. Such prior art retractors are not conformable to an individual patient's dental/mouth architecture and thus delimited to the size and configuration of an individual patient's mouth and dentition. As a result, drawbacks and limitation of existing solutions for protecting the soft tissue surrounding the mouth and teeth undergoing whitening or other treatment persist.

[0006] Accordingly, there remains a need for an efficacious dental protective device and system that minimizes or prevents irritation and soreness to the mouth and gingiva of a patient undergoing dental treatment such as teeth whitening, is ergonomic, readily put and kept in place, is adaptable to a patient's mouth and teeth architecture, and minimizes bulk and discomfort detracting from the experience of the patient.

SUMMARY OF INVENTION

[0007] The present disclosure is directed to various embodiments of protective dental appliances and related methods having a smart material portion that include a shape memory polymer for impeding contact of a dental treatment agent with a portion of soft tissue of a user's mouth. The device and method employ a mouthpiece adaptable to at least a portion of the user's mouth and a smart material portion on at least an outer perimeter of the mouthpiece, wherein the smart material portion includes a shape memory polymer such that at least a portion of the shape memory polymer is activated by a tension stimulus whereby the smart material portion conformably sets a protective interface upon at least a portion of an adjacent soft tissue surface when the dental appliance is placed in the user's mouth. In exemplary embodiments the dental appliance retains a portion of the user's mouth to thereby facilitate access to at least a teeth portion.

[0008] In one representative embodiment, the adjacent soft tissue surface is at least a portion of the user's gingiva and the tension stimulus activating the smart material portion is a difference in temperature between the user's gingiva and a teeth portion whereby the protective interface is thermoset upon a corresponding surface of the user's gingiva.

[0009] The smart material portion may be applied in a suspension, suspended particulate composition, gel, solid or combinations thereof. In some embodiments, the smart material portion is provided in a dispersion of the shape memory polymer in a suspension or solvent. Suitable solvents for such dispersions may include biocompatible and nontoxic carrier media such as, for example, water or ethanol. Exemplary shape memory polymers employed in smart material compositions may contain various shape memory polymers such as a block co-polymer of polyethyleneoxide (PEO) and polyethylene terephthalate (PET) and block co-polymers containing polystyrene and poly(l, 4-butadiene).

[0010] A representative embodiment provides a dental appliance the smart material portion may be delivered in a suspension of particles in a solvent contained within a syringe. Exemplary embodiments may further provide in a separate syringe a dental treatment agent such as a whitening composition including carbamide peroxide.

[0011] In exemplary embodiments, the tension stimulus activating the shape memory polymer of the smart material portion of the oral care retainer is the user's gingival temperature whereby constrained correspondence upon contact of the shape memory polymer with the user's gingiva thermosets a protective interface.

[0012] In some embodiments, the smart material portion is over-molded on the mouthpiece such that at least a portion of the shape memory polymer is stimulated to tensionably conform to a portion of the user's soft tissue. The smart material portion may also be provided in a detachable preformed sleeve configured for mated correspondence about the perimeter of the mouthpiece such that at least a portion of the smart material portion is stimulated to tensionably conform to the portion of the user's soft tissue.

[0013] In several embodiments, the smart material portion may be integrated in a unitary oral care retainer configuration so as to form a bulk portion spaced a distance from the smart material portion and not subject to constrained correspondence upon contact with a portion of the user's gingiva to thereby set a protective interface, or barrier between a portion of the user's soft tissue, including but not limited to the gingiva, and the dental treatment agent to expose a treatment area, including but not limited to a teeth portion of the user's mouth.

[0014] Related methods for protecting at least a portion of soft tissue of a user's mouth during dental treatments comprising steps of positioning a dental appliance in the user's mouth to thereby facilitate access to a teeth portion, applying a tension stimulus to a smart material portion including a shape memory polymer wherein the smart material portion conforms to a portion of soft tissue upon contact to thereby configure a protective interface in the user's mouth, and treating the teeth portion for a predetermined time. The step of applying a tension stimulus may emanate from a difference in temperature between the user's gingiva and a teeth portion whereby the protective interface is thermoset upon a corresponding surface of the user's gingiva. The step of positioning a dental appliance in the user's mouth may further include orienting a bulk portion of the mouthpiece to retain and thereby facilitate access to a portion of the user's mouth for applying a dental treatment agent.

[0015] Particular efficacies are attained by methodologies of employing the smart material based oral care retainer for applying dental whitening compositions including peroxides such as carbamide peroxide.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the drawings, identical and similar reference numerals sharing a common single integer constituting the last number thereof generally refer to the same or counterpart components throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the inventive subject matter.

[0017] FIGS. 1A-1C are photographs showing steps in employing a conventional retainer system.

[0018] FIG. 2 depicts a perspective view of an exemplary embodiment of a protective oral care retainer depicting a smart material provided in a syringe for applying to the mouthpiece.

[0019] FIG. 3 is a perspective representation of an exemplary embodiment of a protective oral care retainer depicting conformable smart material and bulk portions the mouthpiece. [0020] FIG. 4 a perspective representation of an exemplary embodiment of a protective oral care retainer depicting smart material portion provided as a detachable sleeve for the mouthpiece.

[0021] FIG. 5. is a schematic illustration of the shape memory effect exerted by a tension stimulus.

[0022] FIG. 6 is a graphic depiction of the strain-memory of the shape memory polymer as a function of temperature. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The disclosed subject matter will become better understood through review of the following detailed description in conjunction with the figures. The detailed description and figures provide example embodiments of the invention described herein. Those skilled in the art will understand that the disclosed examples may be varied, modified, and altered without departing from the scope of the invention described herein.

[0024] Throughout the following detailed description, various examples of dental appliances, smart materials including shape memory polymers and related oral care methods are provided. Related features in the examples may be identical, similar, or dissimilar in different examples. For the sake of brevity, related features will not be redundantly explained in each example. Instead, the use of related feature names will cue the reader that the feature with a related feature name may be similar to the related feature in an example explained previously. Features specific to a given example will be described in that particular example. The reader should understand that a given feature need not be the same or similar to the specific portrayal of a related feature or example.

[0025] The present disclosure describes various embodiments of devices and methods to provide a smart material based dental appliance having a shape memory polymer activated by a tension stimulus to conform with and thereby provide a protective interface upon a specific area of the soft tissue in a mouth. By thus providing a smart material portion facilitated barrier preventing contact between dental or oral care treatment agent upon corresponding gingiva and other soft tissue of a user's mouth, the disclosed subject matter provides a convenient and efficacious safeguard to avoid associated contraindications including, for example, gingival irritation and soreness. In some embodiments, such as implementations used forteeth whitening procedures, a smart material protective layer impedes contact of a whitening or bleaching agent with surrounding gingiva. A particular dental treatment application includes carbamide peroxide and is particularly efficacious when applied in professional level concentrations of, for example, 22% - 24%. Oral care protective appliances and methods described herein can be consumer products for home use or commercial products used by a professional; in both cases the user, i.e., a home user or a patient, is the user of the disclosed subject matter.

[0026] As used herein, the term "smart material" should be understood to refer to any one or more of a variety of compositions including one or more shape memory polymers subject to tension stimulus to conform with an adjacent surface. One such tension stimulus activating the smart material portion is a difference in temperature between the user's teeth and the gingiva whereby constrained correspondence with the portion of the user's gingiva is thermoset. Another tension stimulus that could be employed to activate the smart material portion include light of a particular wavelength range, such as for example, in the infrared spectrum.

Alternative tension stimuli could include pharmaceutical or chemical compositions such as, for example, ionic, electro-chemical, pH or biologically induced. Yet further tension stimuli could include, without limitation, electromagnetics, electro-activated or light responsive.

[0027] As used herein, the term "shape memory polymer" should be understood to include any polymer subject to a tension stimulus in order to conform in constrained correspondence with at least a portion of the user's mouth. Exemplary shape memory polymers include, without limitation, polyurethane, polyester, polyhydroxyproline, polysilamine, block co polymer of polyethyleneoxide (PEO) and polyethylene terephthalate (PET), block co-polymers containing polystyrene and poly(l, 4-butadiene), polyvinyl alcohol (PVA), polyamides (Nylon) and _poly(tetramethyleneglycol (PTMG). The smart material portion may be a suspension, including a gel, paste or lotion, semi-solid or semi-rigid. In some representative embodiments the smart material portion by be a dispersion of the shape memory polymer in a solvent such as, for example, ethanol or water.

[0028] To further define terminology as used herein, "protective interface" refers to the area where the tensioned conformance of the smart material portion exerts sufficient tensioned pressure against a corresponding surface area of adjacent soft tissue, including without limitation, gingiva, of a user's mouth such that the coextensive surface of the smart material portion and the soft tissue provides a barrier impeding or preventing contact the a dental treatment agent from coming into contact with a portion of the user's mouth soft tissue. [0029] Now referring to FIGS. 2-4 illustrating representative embodiments, a dental appliance 10 for impeding contact of a dental treatment agent 22 with at least a portion of an adjacent soft tissue surface of a user's mouth. Dental appliance 10 includes a mouthpiece 12 adaptable to at least a portion of the user's mouth for placing in an area corresponding to the labial vestibule of the mouth of a user, thereby keeping lip tissue away from the tooth and gum surfaces. A smart material portion is deposited on a curved perimeter 16 of mouthpiece 12. Smart material portion 14 includes a shape memory polymer whereby a tension stimulus activates the smart material portion 14 to thereby conformably set a protective interface upon the adjacent soft tissue surface so as to impede or prevent contact with a dental treatment agent when the dental appliance 10 is placed in the user's mouth.

[0030] In representative embodiments, mouthpiece 10 is dimensioned to retract a soft tissue portion, such as, for example, the lips and proximal soft tissue inside the mouth such as shown in FIGS. 1A, IB and 1C, and the smart material portion is deposited such that a protective barrier formed by conformed correspondence is formed upon the gingiva surrounding teeth of the user's mouth, and wherein the tension stimulus activating the smart material portion is a difference in temperature between the user's teeth and the gingiva whereby constrained correspondence with the portion of the user's gingiva is thermoset.

[0031] FIG. 2 shows an exemplary embodiment wherein smart material portion 14 is provided in a gel or suspension applied to the perimeter or rim layer 16 of the dental appliance 10 and the dental treatment agent 22 is a whitening composition including carbamide peroxide enclosed within a syringe 20. Mouthpiece 12 has an inner curved front lip 16 shaped to complement a frontal surfaces of the upper and lower dental arches and an outer curved lip 18 for placement in the labial vestibule so as to retract corresponding portions of the upper and lower lips away from the teeth and thereby open access to the portion of the user's mouth being treated. Thus, dental appliance 10 fits both an upper dental arch and lower dental arch in a manner similar to the prior art device shown in FIGS. 1A - 1C to allow positioning of the mouthpiece 12 in the labial vestibule of the user. Hence, the upperand lowerfrontal teeth may be exposed while the gingival tissue that surround the teeth and the alveolar parts of the jaws can be covered with the protective smart material portion 14. As still further shown in FIGS. 1A - 1C, the bulk portion of conventional counterparts of mouthpiece 12 retains the soft tissue inside of a user's lips and mouth opposing the dental arches to facilitate access to a teeth portion of the user's dental arches. In this position, the mouthpiece 12 can expose a teeth portion including the upper and lower incisors, cuspids, and first bicuspids for facilitating administration of a whitening or other treatment while impeding contact with the gingiva of the user and resulting contraindications such as irritation and soreness of the occluded surfaces in a portion of the user's mouth.

[0032] FIG. 3 shows embodiments represented by dental appliance 100 providing mouthpiece 102 with a smart material portion in a rim layer 104 over-molded along an inner perimeter 106 of mouthpiece 100 such that placement of the dental appliance 100 orients rim layer 104 in a position where the rim layer 104 conformably thermosets a protective interface corresponding to an adjacent surface of a portion of the user's gingiva to thereby prevent contact of the dental treatment. Rim layer 104 may be composed of an elastomer containing a shape memory polymer such as, for example, polyurethane, polyester, and polyvinyl alcohol based block co-polymer.

[0033] Some representative embodiments are drawn toward a mouthpiece 102 having a smart material portion 104 enclosed within a cartridge disposed about rim 106 such that opening the cartridge after insertion in the user's mouth dispenses the mart material portion 22 provided in a dispersion, suspension or gel on adjacent soft tissue of the users mouth so as to conformably thermoset a protective interface corresponding to at least a portion of an adjacent soft tissue surface when dental appliance 100 is placed in the user's mouth. As in the representative embodiment illustrated in FIG. 1, the mouthpiece 102 provides a bulk portion spaced back a distance such that at least a portion of the shape memory polymer is not activated and thereby retains at least a portion of the user's mouth so as to facilitate access to a treatment area including but not limited to a teeth portion when the dental appliance 100 is placed in the user's mouth.

[0034] As with embodiments employing the suspension smart material portion represented in FIG. 2, dental appliance 100 having a layered rim (104) wherein the shape memory polymer is integrated within the semi-solid or solid sleeve material. Alternative embodiments may provide layered rim (104) as a capsule enclosing a suspension of a shape memory polymer dispersed in a solvent within a smart material potion (104) shown in FIG. 3. As in the counterpart embodiment shown in FIG. 2, he tension stimulus activating the smart material portion is a difference in temperature between the user's teeth and gingiva whereby constrained correspondence thermosets a conforming protective interface with the user's gingiva upon contact of the shape memory polymer.

[0035] FIG. 4 represents embodiments of dental appliance 200 wherein the smart material portion is provided in a detachable sleeve (206) is preformed in a configuration dimensioned for mated correspondence such that detachable sleeve 204 may be removeably mated about mouthpiece perimeter 206 such that the smart material portion of mouthpiece 202 tensionably conforms to an adjacent surface of the user's gingiva when placed in a user's mouth.

[0036] It is to be understood that the representative embodiments described herein demonstrate some but not every aspect and application of the smart material based dental appliance. Depending on the application, the desired shape memory polymer distribution, type and concentration in the smart material portion can be adjusted. For example, tooth whitening applications may require high concentrations of the shape memory polymer to be placed along the inner periphery of a dental appliance, such as shown in FIGS. 2 - 4. However, differing concentrations of shape memory polymer or distributions of the smart material portion within the mouthpiece may be employed to facilitate access to other areas of a user's mouth. For example, to access posterior or embedded sections of the oral cavity such as, for example, the root pulp or cementum or other deep-set sections of the labial vestibule of the mouth.

[0037] FIG. 5 is a schematic depiction of physical property imparting tensionable conformability exhibited by the shape memory polymer of the smart material portion of the described and claimed dental appliance. In particular, a shape memory polymer provides a platform whereby an external tension stimulus deforms the shape memory polymer molecules into constrained twisted configurations that have no particular alignment. When subjected to a tension stimulus in context of the dental appliance described and claimed herein such as, for example, a user's gingival temperature, the tensioned molecules randomly twist and intertwine and thereby to conform with an adjacent surface, triggered in the representative embodiments by the thermal energy of the soft tissue of the mouth. The bulk portion of the dental appliance not subject to the tension stimulus maintains its molecular alignment and shape. Removing the tension conversely straightens and aligns the shape memory polymer molecules in its original uniform orientation and dimension and realigns with the bulk portion and thus the mouthpiece 12 returns to its non-tensioned configuration.

[0038] FIG. 6 is a graphic depiction of the tension stimulus applied in representative embodiments as described and claimed herein employing thermal loading wherein shape memory polymer (SMP) stress measured in MPa is shown as a function of temperature. Heating (H) stimulates the SMP stress loading (L) the tension to a deformable state adapting to an adjacent surface. Cooling (C) returns the SMP to 0 stress and the permanent, unstrained or untensioned state and/or shape as shown in FIG. 5. Representative embodiments described herein employ such thermal stimulus based on the difference between teeth and soft tissue temperature of a user's mouth.

[0039] It is contemplated that the inventive subject matter may include embodiment wherein mouthpiece configured such as shown in FIGS. 2 -4 have a shape memory polconformably thermosets a protective interface corresponding to at least a portion of an adjacent soft tissue surface when the dental appliance is placed in the user's mouth and wherein the mouthpiece includes a bulk portion spaced back a distance such that at least a portion of the shape memory polymer is not activated and thereby retains at least a portion of the user's mouth so as to facilitate access to a treatment area when the dental appliance is placed in the user's mouth. [0040] The inventive subject matter further contemplates methods of preventing contact of a dental treatment agent with soft tissue of a user's oral cavity including the steps of positioning a dental appliance in the mouth of the user to thereby facilitate access to a teeth portion of a user's mouth, thermosetting a smart material portion including a shape memory polymer upon a portion of soft tissue proximate to the teeth portion such that the smart material portion conforms to the soft tissue to thereby configure a protective interface in the user's mouth; and applying the dental treatment agent for a predetermined time.

[0041] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. [0042] The indefinite articles "a" and "an," as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

[0043] The phrase "and/or," as used herein in the specification and in the claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with "and/or" should be construed in the same fashion, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the "and/or" clause, whether related or unrelated to those elements specifically identified.

[0044] As used in the specification and in the claims, "or" should be understood to have the same meaning as "and/or" as defined above. For example, when separating items in a list, "or" or "and/or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or, when used in the claims, "consisting of," will refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "exactly one of."

[0045] As used in the specification and in the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified.

[0046] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0047] In the claims, as well as in the specification above, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "composed of," and the like are to be understood to be open-ended, i.e., to mean including but not limited to.

[0048] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.