Appliance, and dental instrument and use thereof
By using a temperature-sensitive adsorption layer and a temperature-sensitive adhesive layer in the aligner, the adsorption and adhesion forces are controlled by temperature changes, solving the problems of loosening and falling off of invisible aligners and the complexity of accessory operation. This achieves a balance between easy removal and secure wearing, improving the efficiency and safety of dental treatment.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- WUXI EA MEDICAL INSTR TECH
- Filing Date
- 2025-12-31
- Publication Date
- 2026-07-09
AI Technical Summary
Existing invisible aligners have problems such as loosening and falling out during wear, complicated accessory operation, high risk of falling out, and risk of demineralization and tooth decay. Furthermore, it is difficult to achieve a balance between easy removal and secure wearing.
It employs a temperature-sensitive adsorption layer and a temperature-sensitive adhesive layer, utilizing temperature-sensitive polymers such as PNIPAM and crystalline polymers to regulate the adsorption and adhesion forces through temperature changes, thereby achieving adjustable adsorption and adhesion between the orthodontic appliance and the teeth, allowing for easy peeling at low temperatures and secure wearing at high temperatures.
It improves the stability of the orthodontic appliance and the ease of removal, reduces the complexity of accessory operations and the risk of demineralization and caries, and enhances the efficiency of dentists and the convenience of treatment for patients.
Smart Images
Figure CN2025148093_09072026_PF_FP_ABST
Abstract
Description
Orthodontic appliances, dental instruments and their applications
[0001] This application claims priority to Chinese patent applications 2024119950438 and 2024119950423, both filed on December 31, 2024. The full text of the aforementioned Chinese patent applications is incorporated herein by reference. Technical Field
[0002] This invention relates to an orthodontic appliance, dental instruments, and their applications. Background Technology
[0003] The shape of the alveolar bone in invisible dental appliances and aligners differs slightly from the shape of natural teeth. Furthermore, issues such as short crowns, insufficient undercuts, missing teeth, and excessive saliva and food debris in the mouth can often lead to loosening and detachment of the aligners. Therefore, during dental treatment, orthodontists will bond attachments to the patient's teeth to firmly secure the aligners and ensure that the teeth move in the intended direction.
[0004] However, there are currently several problems with attachments: 1. Bonding attachments to the patient's teeth reduces the dentist's work efficiency; 2. There is a risk of attachments falling off during treatment; 3. It is difficult to remove attachments at the end of treatment; 4. Demineralization caries are more likely to occur around the attachments.
[0005] To address the aforementioned issues, patent application CN116942338A provides a method for preparing a suction cup structure during the hot-pressing process of an invisible aligner. This method reduces the need for attachments by generating an adhesive force between the suction cup structure and the teeth. Patent application CN219439483U describes a method for installing hollow suction components inside the aligner. The suction components are positioned inside the aligner corresponding to one of the user's teeth, and the suction components create negative pressure after degassing, generating an adhesive force with the teeth. However, these patents only focus on the fixation of the invisible aligner during wear; the adhesive force cannot be changed when it is removed, and the generation of negative pressure in each suction cup structure requires manual degassing, making the operation neither simple nor convenient. Summary of the Invention
[0006] To address the shortcomings of existing orthodontic appliances and dental instruments in simultaneously achieving both secure fit and easy removal, this invention provides an orthodontic appliance, dental instruments, and their applications. This appliance and instrument can simultaneously achieve both secure fit and easy removal.
[0007] The present invention solves the above-mentioned technical problems through the following technical solutions.
[0008] The present invention provides an orthodontic appliance comprising a housing and a cavity. The housing includes a wrapping layer and a temperature-sensitive adsorption layer. The cavity formed by the wrapping layer is used to accommodate teeth. The temperature-sensitive adsorption layer is disposed in at least a portion of the surface of the wrapping layer near the teeth. The material of the temperature-sensitive adsorption layer includes a polymer whose hydrophilicity / hydrophobicity changes with temperature.
[0009] In this invention, the adsorption force between the temperature-sensitive adsorption layer and the teeth can be adjusted by changes in the external temperature, thereby changing the adsorption force between the orthodontic appliance and the teeth.
[0010] The thermosensitive adsorption layer is made of poly(N-isopropylacrylamide), abbreviated as PNIPAM, a thermosensitive polymer. Its thermosensitive principle is mainly based on the competition between the hydrophilic amide groups and the hydrophobic isopropyl groups near the lower critical solution temperature (LCST), leading to a change in hydrophilicity / hydrophobicity. The LCST of PNIPAM is approximately 32°C. Below this temperature, the hydration of the amide groups in PNIPAM dominates, exhibiting hydrophilicity and an extended chain conformation. When the temperature rises above the LCST, the hydrophobic effect of the isopropyl groups in PNIPAM becomes dominant, causing the polymer chains to physically coil, and the enhanced inter-chain interactions trigger phase separation. This change in polymer chain conformation near the LCST results in a significant change in polymer volume. Below the LCST, water molecules form hydrogen bonds with the amide groups of PNIPAM, causing the polymer to absorb water and swell. When the temperature rises above the LCST, the hydrogen bonds are broken, and the hydrophobic effect of the isopropyl groups repels water molecules, causing the polymer to shrink and its volume to decrease. Therefore, due to its thermosensitive volume swelling-shrinkage transformation, PNIPAM can generate internal negative pressure during shrinkage, enhancing its adsorption capacity with surrounding substances. PNIPAM's LCST is approximately 32°C, near human body temperature, thus allowing it to be applied to the human body to achieve thermosensitive adsorption force changes. Therefore, during the insertion and removal of orthodontic appliances, the thermosensitive adsorption layer can switch its adsorption force according to changes in ambient temperature, eliminating the need for attaching and removing attachments.
[0011] In this invention, preferably, the material of the temperature-sensitive adsorption layer includes poly(N-isopropylacrylamide) and / or poly(N-isopropylacrylamide) copolymer.
[0012] Preferably, the number average molecular weight of the poly(N-isopropylacrylamide) is 10,000-100,000, for example, 40,000.
[0013] Preferably, the number-average molecular weight of the poly(N-isopropylacrylamide) copolymer is 1,000-500,000, for example, 30,000.
[0014] Preferably, the poly(N-isopropylacrylamide) copolymer is formed by polymerization of poly(N-isopropylacrylamide) and a first monomer; the first monomer includes one or more of acrylic acid, acrylate and acrylamide.
[0015] Preferably, the mass ratio of the poly(N-isopropylacrylamide) to the first monomer is 1:(0.01-100).
[0016] In some specific embodiments of the present invention, the poly(N-isopropylacrylamide) copolymer is formed by polymerizing poly(N-isopropylacrylamide) and acrylic acid; the mass ratio of poly(N-isopropylacrylamide) to acrylic acid is 1:0.1.
[0017] In this invention, preferably, the LCST of the material of the thermosensitive adsorption layer is 25-45°C. Here, LCST refers to the temperature at which the hydrophilicity / hydrophobicity of the material of the thermosensitive adsorption layer changes.
[0018] In this invention, preferably, the peel strength of the temperature-sensitive adsorption layer below 25°C is less than 5 N / m, wherein the peel strength below 25°C means the peel strength between the temperature-sensitive adsorption layer and the tooth in an environment below 25°C.
[0019] Preferably, the peel strength of the temperature-sensitive adsorption layer at 20°C is below 5 N / m, where the peel strength below 20°C means the peel strength between the temperature-sensitive adsorption layer and the tooth at an environment of 20°C.
[0020] Preferably, the peel strength of the temperature-sensitive adsorption layer at 20°C is 1-5 N / m.
[0021] In this invention, preferably, the peel strength of the temperature-sensitive adsorption layer at 30-37°C is above 20 N / m, wherein the peel strength at 30-37°C means the peel strength between the temperature-sensitive adsorption layer and the tooth under normal oral environment (30-37°C).
[0022] Preferably, the peel strength of the temperature-sensitive adsorption layer at 37°C is above 20 N / m. Here, the peel strength at 37°C refers to the peel strength between the temperature-sensitive adsorption layer and the tooth at 37°C.
[0023] Preferably, the peel strength of the temperature-sensitive adsorption layer at 37°C is 20-1000 N / m.
[0024] In this invention, preferably, the hydrophilicity / hydrophobicity switching time of the material in the temperature-sensitive adsorption layer is less than 5 minutes. The hydrophilicity / hydrophobicity switching time of the material in the temperature-sensitive adsorption layer means the time elapsed when the external temperature changes from T1 to T2, during which the material in the temperature-sensitive adsorption layer changes from being predominantly hydrophilic to being predominantly hydrophobic, or vice versa.
[0025] The time it takes for the peel strength to change from 5 N / m to 20 N / m is defined as the time elapsed between the peel strength and the peel strength of the adsorption force.
[0026] In this invention, the method for preparing the orthodontic appliance may include the following steps: coating a solution onto at least a portion of the surface of the wrapping layer near the teeth, and then curing it to form a temperature-sensitive adsorption layer; wherein the solution includes the material and solvent of the temperature-sensitive adsorption layer.
[0027] The coating may be, for example, brushing, spraying, spin coating, or dip coating.
[0028] The solvent is, for example, water.
[0029] In the solution, the mass concentration of the material of the thermosensitive adsorption layer is preferably 1%-20%, for example, 10%. Here, % represents the percentage of the mass of the material of the thermosensitive adsorption layer relative to the mass of the solution.
[0030] The curing process can be, for example, heating. Upon heating, the solvent evaporates, and the material of the temperature-sensitive adsorption layer solidifies to form the temperature-sensitive adsorption layer.
[0031] The curing temperature is preferably 20-80℃, for example 40℃.
[0032] The curing time is preferably 1-72 hours, for example, 24 hours.
[0033] The preparation method of the coating layer can be a conventional preparation method in the art.
[0034] In this invention, preferably, the coating layer is prepared by compression molding, 3D printing technology or CNC machine tool cutting technology.
[0035] The molding temperature is preferably 180-260°C, for example, 200°C.
[0036] The molding time is preferably 10-120s, for example 60s.
[0037] Preferably, the thickness of the temperature-sensitive adsorption layer is less than 100 μm, for example, 60 μm. The molding process allows for a tolerance of ±100 μm in dental model error, and a thickness of less than 100 μm for the temperature-sensitive adsorption layer does not affect the orthodontic performance of the appliance.
[0038] In some specific embodiments of the present invention, the molding process further includes cooling, cutting, and polishing steps.
[0039] In this invention, preferably, at least a portion of the cavity structure is fitted to the corresponding teeth.
[0040] In this invention, the wrapping layer can be a single-layer structure or a multi-layer structure.
[0041] In this invention, preferably, the temperature-sensitive adsorption layer is disposed on the entire surface of the coating layer near the tooth side.
[0042] In this invention, preferably, the material of the coating layer is a polymer material.
[0043] The polymer material is, for example, one or more of polyurethane, polyamide, and copolyester.
[0044] The polyurethane is, for example, thermoplastic polyurethane.
[0045] In this invention, preferably, the thickness ratio of the temperature-sensitive adsorption layer to the coating layer is 1:(5-40), more preferably 1:(5-20), for example 1:7.5, 1:12.5, 1:18.8 or 1:37.5.
[0046] In this invention, the thickness of the temperature-sensitive adsorption layer is preferably 20-100 μm, and more preferably 60-100 μm.
[0047] In this invention, preferably, the thickness of the temperature-sensitive adsorption layer below LCST is less than 200 μm.
[0048] The present invention also discloses the application of the aforementioned orthodontic appliance in orthodontic treatment.
[0049] The present invention provides a dental instrument comprising a housing and a cavity, the housing comprising a wrapping layer and a temperature-sensitive adhesive layer, the cavity formed by the wrapping layer for accommodating a tooth, the temperature-sensitive adhesive layer being disposed in at least a portion of the surface of the wrapping layer near the tooth; the material of the temperature-sensitive adhesive layer comprising a temperature-sensitive crystalline polymer.
[0050] In this invention, the term "thermosensitive crystalline polymer" refers to a polymer whose crystallinity changes with temperature.
[0051] In this invention, the adhesion force between the dental instrument and the tooth can be controlled by changes in the external temperature, thereby altering the adhesion force between the dental instrument and the tooth.
[0052] The temperature-sensitive adhesive layer is made of polyacrylate, a temperature-sensitive crystalline polymer. Crystalline polymers typically consist of crystalline and amorphous phases, and their crystallinity changes with temperature. At low temperatures, highly crystalline polymer molecules exhibit a regular condensation state, resulting in low adhesion. However, upon heating, the crystalline polymer undergoes a crystallization-melting phase transition, causing the ordered molecular arrangement within the crystalline range to become disordered, thus increasing adhesion. Therefore, by inducing this crystallization-melting phase transition through changes in external temperature, the adhesion strength can be controlled. In practical applications involving humans, a temperature trigger around 37°C (body temperature) is most convenient. The brittleness of crystalline polymers in their crystalline state allows for relatively easy peeling from the substrate. Therefore, by controlling the crystallization-melting trigger temperature around 37°C, different levels of adhesion strength can be achieved on the human body. Thus, during the insertion and removal of dental instruments, the temperature-sensitive adhesive layer can switch adhesion strength according to changes in ambient temperature, eliminating the need for attaching and removing attachments.
[0053] In this invention, preferably, the temperature-sensitive crystalline polymer comprises polyacrylate.
[0054] Preferably, the polyacrylate has the structural formula shown in Formula I, where n is an integer from 50 to 500 and X is an integer from 2 to 20.
[0055] Preferably, X is 14 or 18.
[0056] Preferably, the monomer of the polyacrylate includes acrylate.
[0057] Preferably, the monomers of the polyacrylate include octadecyl acrylate and tetradecyl acrylate.
[0058] Preferably, the molar ratio of octadecyl acrylate to tetradecyl acrylate is 1:(0.1-10), for example, 1:1.
[0059] Preferably, the molar ratio of the octadecyl acrylate to the monomer of the polyacrylate is 40%-60%.
[0060] In this invention, preferably, the peel strength of the temperature-sensitive adhesive layer in the molten state is 20 N / m or higher. The peel strength in the molten state refers to the peel strength between the temperature-sensitive adhesive layer and the teeth when the material of the temperature-sensitive adhesive layer is in a molten state. The molten state refers to the state where the crystalline phase content of the crystalline polymer is below 30% at low temperature crystallinity. Low temperature crystallinity refers to the crystallinity of the crystalline polymer at 0°C.
[0061] Preferably, the temperature-sensitive adhesive layer is in a molten state at a temperature of 37°C.
[0062] Preferably, the temperature-sensitive adhesive layer has a peel strength of 20-1000 N / m or higher at 37°C.
[0063] In this invention, preferably, the peel strength of the temperature-sensitive adhesive layer in the crystalline state is less than 10 N / m. The peel strength in the crystalline state means the peel strength between the temperature-sensitive adhesive layer and the tooth when the material of the temperature-sensitive adhesive layer is in the crystalline state. The crystalline state is the state in which the crystalline phase content of the crystalline polymer is 70% or more at low temperature.
[0064] Preferably, the temperature-sensitive adhesive layer is in a crystalline state at a temperature of 20°C.
[0065] Preferably, the peel strength of the temperature-sensitive adhesive layer at 20°C is 1-10 N / m.
[0066] In this invention, preferably, the crystallinity switching time of the temperature-sensitive crystalline polymer is less than 5 minutes. The crystallinity switching time means the time it takes for the temperature-sensitive crystalline polymer to change from a low-temperature crystallinity of 30% to 70%, or from 70% to 30%, when the external temperature changes from T1 to T2.
[0067] In this invention, preferably, the temperature range in which the crystalline phase content of the temperature-sensitive crystalline polymer changes from 30% to 70% at low temperature is 0-60°C.
[0068] In this invention, preferably, the material of the temperature-sensitive adhesive layer further includes a film-forming agent. The film-forming agent is a polymer capable of forming a continuous thin film.
[0069] Preferably, the film-forming agent comprises one or more of acrylic resin, butadiene resin, polyurethane resin, and aromatic isocyanate. Each of these categories—acrylic resin, butadiene resin, polyurethane resin, and aromatic isocyanate—represents a class of substances, which may include different specific types. The present invention selects the above-mentioned types of film-forming agents, which, on the one hand, enables the dental film to have a colorless and transparent appearance, and on the other hand, improves the coating effect of the temperature-sensitive adhesive layer, increases coating uniformity, and improves coating operability.
[0070] Preferably, the acrylic resin is ethyl polyacrylate.
[0071] The number-average molecular weight of the polyethyl acrylate is, for example, 40,000.
[0072] Preferably, the mass ratio of the thermosensitive crystalline polymer to the film-forming agent is (0.1-20):(1-20), for example, 1:1.
[0073] In this invention, preferably, the material of the temperature-sensitive adhesive layer further includes an emulsifier.
[0074] The emulsifier preferably includes one or more of alkyl sulfates, stearates, and alkylbenzene sulfonates.
[0075] Preferably, the alkyl sulfate has the general formula C0. n H 2n+1 SO4X, where n is any integer from 1 to 20, and X is selected from sodium, magnesium, aluminum, potassium, or calcium.
[0076] Preferably, the alkyl sulfate is sodium dodecyl sulfate.
[0077] Preferably, the alkylbenzene sulfonate has the general formula C2. n H 2n+1 C6H4SO3X, where n is any integer from 1 to 20, and X is selected from sodium, magnesium, aluminum, potassium, or calcium.
[0078] Preferably, the stearate is sodium stearate.
[0079] Preferably, the mass ratio of the thermosensitive crystalline polymer to the emulsifier is (0.1-20):(0.1-2), for example, 10:0.5.
[0080] In this invention, preferably, the material of the temperature-sensitive adhesive layer further includes a crosslinking agent.
[0081] Preferably, the crosslinking agent includes propoxylated neopentyl glycol diacrylate and / or N,N-methylenebisacrylamide.
[0082] Preferably, the mass ratio of the thermosensitive crystalline polymer to the crosslinking agent is (0.1-20):(0.1-1).
[0083] In this invention, preferably, the material of the temperature-sensitive adhesive layer further includes a fragrance.
[0084] Preferably, the flavoring agent includes one or more of menthol, geraniol acetate, and edible fruit flavorings.
[0085] Preferably, the mass ratio of the thermosensitive crystalline polymer to the crosslinking agent is (0.1-20):(0.01-0.1).
[0086] In this invention, the method for preparing the dental instrument may include the following steps: coating a solution onto at least a portion of the surface of a coating layer, and then curing it to form a temperature-sensitive adhesive layer; wherein the solution includes a material for the temperature-sensitive adhesive layer and a solvent, and the material for the temperature-sensitive adhesive layer includes a temperature-sensitive crystalline polymer. After curing, the solvent gradually evaporates, and the final temperature-sensitive adhesive layer does not contain any solvent.
[0087] Preferably, the material of the temperature-sensitive adhesive layer further includes one or more of a film-forming agent, an emulsifier, a crosslinking agent, and a fragrance.
[0088] Preferably, the mass ratio of the thermosensitive crystalline polymer to the solvent in the solution is (0.1-20):(30-90), for example, 1:9.
[0089] In some specific embodiments of the present invention, the mass ratio of the thermosensitive crystalline polymer, the film-forming agent, the emulsifier and the solvent in the solution is (0.1-20):(1-20):(0.1-2):(30-90).
[0090] In certain specific embodiments of the present invention, the mass ratio of the thermosensitive crystalline polymer, the film-forming agent, the emulsifier, the solvent, the crosslinking agent, and the fragrance in the solution is (0.1-20):(1-20):(0.1-2):(30-90):(0.1-1):(0.01-0.1).
[0091] In some specific embodiments of the present invention, the mass ratio of the thermosensitive crystalline polymer, the film-forming agent and the emulsifier in the solution is 10:10:0.5.
[0092] The coating may be, for example, brushing, spraying, spin coating, or dip coating.
[0093] The solvent is, for example, water.
[0094] The curing process can be, for example, heating. Upon heating, the solvent evaporates, and the material of the temperature-sensitive adhesive layer solidifies to form the temperature-sensitive adhesive layer.
[0095] The curing temperature is preferably 30-80℃, for example 40℃.
[0096] The curing time is preferably 1-72 hours, for example 8 hours.
[0097] The preparation method of the coating layer can be a conventional preparation method in the art.
[0098] In this invention, preferably, the coating layer is prepared by compression molding, 3D printing technology or CNC machine tool cutting technology.
[0099] The molding temperature is preferably 180-260°C, for example, 200°C.
[0100] The molding time is preferably 10-120s, for example 60s.
[0101] Preferably, the thickness of the temperature-sensitive adhesive layer is less than 100 μm, for example, less than 25 μm. The molding process allows for a tolerance of ±100 μm in dental model error, and a thickness of less than 100 μm for the temperature-sensitive adhesive layer does not affect the orthodontic performance of the dental instrument.
[0102] In some specific embodiments of the present invention, the molding process further includes cooling, cutting, and polishing steps.
[0103] In this invention, preferably, the material of the coating layer is a polymer material.
[0104] The polymer material is, for example, one or more of polyurethane, polyamide, and copolyester.
[0105] The polyurethane is, for example, thermoplastic polyurethane.
[0106] In this invention, the wrapping layer can be a single-layer structure or a multi-layer structure.
[0107] In this invention, preferably, the temperature-sensitive adhesive layer is disposed over the entire surface of the coating layer on the side closest to the teeth.
[0108] In this invention, preferably, at least a portion of the cavity structure is fitted to the corresponding teeth.
[0109] In this invention, preferably, the thickness ratio of the temperature-sensitive adhesive layer to the coating layer is 1:(10-100), for example, 1:7.5, 1:15 or 1:30.
[0110] In this invention, preferably, the mass percentage of the thermosensitive crystalline polymer in the thermosensitive adhesive layer is 20%-80%.
[0111] In this invention, preferably, the thickness of the temperature-sensitive adhesive layer is less than 100 μm, and more preferably 25-100 μm.
[0112] The present invention also discloses the application of the dental instrument as described above in orthodontic treatment.
[0113] In certain embodiments of the present invention, during orthodontic treatment, dental instruments are used to reposition the patient's teeth from a current first layout to a second layout. The dental instruments may substantially conform to the second layout of the patient's teeth, or may be slightly offset in the orthodontic direction, so that the dental instruments can reposition the patient's teeth to the second layout.
[0114] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.
[0115] The reagents and raw materials used in this invention are all commercially available.
[0116] The positive and progressive effects of this invention are as follows:
[0117] The orthodontic appliance of the present invention can adjust the adhesion force between itself and the teeth according to the changes in the external temperature, which can achieve the advantages of easy peeling at low temperatures and high wearing stability at high temperatures.
[0118] The dental instrument of the present invention can adjust the adhesion force between itself and the teeth according to the changes in the external temperature, thus achieving the advantages of easy peeling at low temperatures and high wearing stability at high temperatures.
[0119] The dental instruments of this invention improve dentistry efficiency, enhance patient convenience in removing and replacing instruments during treatment, and increase removal efficiency after treatment, thus better protecting the patient's teeth. Compared to conventional attachments, they reduce the risk of peri-attachment demineralization and caries. Attached Figure Description
[0120] Figure 1 is a schematic diagram of the structure of the orthodontic appliances in Examples 1-5.
[0121] Figure 2 is a cross-sectional view along plane AA of Figure 1.
[0122] Figure 3 is a schematic diagram of the dental instruments in Examples 6-8.
[0123] Figure 4 is a cross-sectional view along plane AA of Figure 3.
[0124] The attached figures are labeled as follows: 1-Encapsulation layer; 2-Thermosensitive adsorption layer; 3-Cavity; 4-Thermosensitive adhesive layer. Detailed Implementation
[0125] The present invention will be described in detail below with reference to embodiments, but this does not imply any adverse limitation on the invention. The present invention has been described in detail, and specific embodiments thereof have been disclosed. It will be apparent to those skilled in the art that various changes and modifications can be made to the specific embodiments of the present invention without departing from the concept and scope of the invention.
[0126] For experimental methods in the following examples where specific conditions are not specified, follow conventional methods and conditions, or select according to the product instructions.
[0127] Examples 1-4
[0128] The temperature-sensitive adsorption layer in Examples 1-4 is made of poly(N-isopropylacrylamide) with a number-average molecular weight of 40,000.
[0129] The wrapping layer is made of thermoplastic polyurethane.
[0130] The method for preparing the orthodontic appliance is as follows:
[0131] The coating layer is prepared by heating the material and then pressing it onto a dental mold. After cooling, it is cut and polished. The heating temperature is 200℃ and the heating time is 60s. The thickness of the coating layer is 0.75mm.
[0132] The method for preparing the temperature-sensitive adsorption layer is as follows: the solution is coated on the entire surface of the coating layer near the tooth side, and after curing, the temperature-sensitive adsorption layer is formed; wherein, the solution includes the material of the temperature-sensitive adsorption layer and water; the mass concentration of the material of the temperature-sensitive adsorption layer in the solution is 10%; wherein, the curing temperature is 40℃ and the time is 24h.
[0133] Example 5
[0134] The temperature-sensitive adsorption layer in Example 5 is a copolymer of poly(N-isopropylacrylamide) and acrylic acid, with a mass ratio of poly(N-isopropylacrylamide) to acrylic acid of 1:0.1 and a number-average molecular weight of 30,000.
[0135] The wrapping layer is made of thermoplastic polyurethane.
[0136] The method for preparing the orthodontic appliance is as follows:
[0137] The coating layer is prepared by heating the material and then pressing it onto a dental mold. After cooling, it is cut and polished. The heating temperature is 200℃ and the heating time is 60s. The thickness of the coating layer is 0.75mm.
[0138] The method for preparing the temperature-sensitive adsorption layer is as follows: the solution is coated on the entire surface of the coating layer near the tooth side, and after curing, the temperature-sensitive adsorption layer is formed; wherein, the solution includes the material of the temperature-sensitive adsorption layer and water; the mass concentration of the material of the temperature-sensitive adsorption layer in the solution is 10%; wherein, the curing temperature is 40℃ and the time is 24h.
[0139] The thickness of the temperature-sensitive adsorption layer and the peel strength at 20°C and 37°C for Examples 1-5 are listed in Table 1 below.
[0140] The peel strength test method is 90° peel, referring to ISO 4578:1990.
[0141] The structural schematic diagram of the orthodontic appliance prepared in the above embodiments 1-5 is shown in Figure 1, and the cross-sectional view along the AA surface is shown in Figure 2. It consists of a shell and a cavity 3. The shell is a temperature-sensitive adsorption layer 2 and a single-layer wrapping layer 1. The cavity 3 formed by the wrapping layer 1 is used to accommodate the teeth. The temperature-sensitive adsorption layer 2 is located on the entire surface of the wrapping layer 1 near the teeth.
[0142] Comparative Example 1
[0143] The orthodontic appliance in Comparative Example 1 does not contain a temperature-sensitive adsorption layer, and all other conditions are the same as in Example 1.
[0144] The thickness of the temperature-sensitive adsorption layer and the peel strength at 20℃ and 37℃ of Comparative Example 1 are listed in Table 1 below.
[0145] Table 1
[0146] As shown in the table above, the peel strength of the orthodontic appliance of this embodiment is only below 2N / m at 20℃ and above 39N / m at 37℃. The orthodontic appliance of this embodiment can achieve the advantages of easy peeling at low temperature and high wearing stability at high temperature, which can make it convenient for patients to easily put on and take off during treatment, while improving the work efficiency of doctors.
[0147] As can be seen from the effects of Examples 1-5, a thickness of 60-100μm for the temperature-sensitive adsorption layer can further improve the stability of wearing at high temperatures, and it is also easy to peel off at low temperatures.
[0148] Comparative Example 1 does not use a temperature-sensitive adsorption layer, and its peel strength is 0, resulting in poor wearing stability at both high and low temperatures.
[0149] Examples 6-8
[0150] The thermosensitive adhesive layer materials of Examples 6-8 consist of a thermosensitive crystalline polymer, a film-forming agent, and an emulsifier, the specific types of which are listed in Table 2. Specifically, the thermosensitive crystalline polymer of Examples 6-8 consists of tetradecyl polyacrylate and octadecyl polyacrylate in a molar ratio of 1:1. The structural formulas of tetradecyl polyacrylate and octadecyl polyacrylate are as follows:
[0151] In the structural formula of polytetradecyl acrylate, X is 14 and n is 100;
[0152] In the structural formula of polyoctadecyl acrylate, X is 18 and n is 100;
[0153] The number average molecular weight of the film-forming agent is 40,000.
[0154] The wrapping layer is made of thermoplastic polyurethane.
[0155] The method for preparing dental instruments is as follows:
[0156] The coating layer is prepared by heating the material and then pressing it onto a dental mold. After cooling, it is cut and polished. The heating temperature is 200℃ and the heating time is 60s. The thickness of the coating layer is 0.75mm.
[0157] The method for preparing the temperature-sensitive adhesive layer is as follows: the solution is coated on the entire area of the surface of the coating layer near the tooth, and after curing, a temperature-sensitive adhesive layer is formed; wherein, the solution is composed of the material of the above-mentioned temperature-sensitive adhesive layer and water, wherein the mass ratio of temperature-sensitive crystalline polymer to water is 1:9; the mass concentration of each material of the temperature-sensitive adhesive layer in the solution is listed in Table 2; wherein, the curing temperature is 40℃ and the time is 8h.
[0158] The thickness of the temperature-sensitive adhesive layer and the peel strength at 20°C and 37°C for Examples 6-8 are listed in Table 2 below.
[0159] The peel strength test method is 90° peel, referring to ISO 4578:1990.
[0160] The structural schematic diagram of the dental instrument prepared in the above embodiments 6-8 is shown in Figure 3, and the cross-sectional view along the AA surface is shown in Figure 4. It consists of a shell and a cavity 3. The shell is a temperature-sensitive adhesive layer 4 and a single-layer wrapping layer 1. The cavity 3 formed by the wrapping layer 1 is used to accommodate the tooth. The temperature-sensitive adhesive layer 4 is provided on the entire area of the surface of the wrapping layer 1 near the tooth.
[0161] Comparative Examples 2-4
[0162] The temperature-sensitive adhesive layer of Comparative Example 2 does not contain temperature-sensitive crystalline polymers, and all other conditions are the same as in Example 6.
[0163] The temperature-sensitive adhesive layer of Comparative Example 3 does not contain temperature-sensitive crystalline polymers, and all other conditions are the same as in Example 7.
[0164] The temperature-sensitive adhesive layer of Comparative Example 4 does not contain temperature-sensitive crystalline polymers, and all other conditions are the same as in Example 8.
[0165] The thickness of the temperature-sensitive adhesive layer and the peel strength at 20°C and 37°C for Comparative Examples 2-4 are listed in Table 2 below.
[0166] Table 2
[0167] As shown in the table above, the dental instrument of the present invention has a peel strength of less than 3 N / m at 20°C and a peel strength of more than 76 N / m at 37°C. The dental instrument of the present invention can achieve the advantages of easy peeling at low temperatures and high wearing stability at high temperatures, which can make it convenient for patients to easily put on and take off during treatment, while improving the work efficiency of doctors.
[0168] Comparative Examples 2-4 used conventional adhesive layers, and the peel strength difference was small at 20℃ and 37℃. The effect of easy peeling could not be achieved at either high or low temperature.
Claims
1. An orthodontic appliance, characterized in that, The orthodontic appliance includes a housing and a cavity. The housing includes a wrapping layer and a temperature-sensitive absorbent layer. The cavity formed by the wrapping layer is used to accommodate teeth. The temperature-sensitive absorbent layer is disposed in at least a portion of the surface of the wrapping layer near the teeth. The material of the temperature-sensitive absorbent layer includes a polymer whose hydrophilicity and hydrophobicity change with temperature.
2. The orthodontic appliance as described in claim 1, characterized in that, The material of the temperature-sensitive adsorption layer includes poly(N-isopropylacrylamide) and / or poly(N-isopropylacrylamide) copolymer; The number average molecular weight of the poly(N-isopropylacrylamide) is 10,000-100,000, for example, 40,000. The number-average molecular weight of the poly(N-isopropylacrylamide) copolymer is 1,000-500,000, for example, 30,000; Preferably, the poly(N-isopropylacrylamide) copolymer is formed by polymerization of poly(N-isopropylacrylamide) and a first monomer; the first monomer includes one or more of acrylic acid, acrylate, and acrylamide. Preferably, the mass ratio of the poly(N-isopropylacrylamide) to the first monomer is 1:(0.01-100).
3. The orthodontic appliance as described in claim 1 or 2, characterized in that, The orthodontic appliance is selected from one or more of the following conditions: (a) The LCST of the material of the temperature-sensitive adsorption layer is 25-45℃; (b) The peel strength of the temperature-sensitive adsorption layer at 25°C is below 5 N / m; (c) The peel strength of the temperature-sensitive adsorption layer at 30-37℃ is above 20N / m; (d) The hydrophilicity / hydrophobicity switching time of the material in the temperature-sensitive adsorption layer is less than 5 minutes.
4. The orthodontic appliance according to at least one of claims 1-3, characterized in that, The orthodontic appliance is selected from one or more of the following conditions: (a) The peel strength of the temperature-sensitive adsorption layer at 20°C is below 5 N / m; Preferably, the peel strength of the temperature-sensitive adsorption layer at 20°C is 1-5 N / m; (b) The peel strength of the temperature-sensitive adsorption layer at 37°C is above 20 N / m; Preferably, the peel strength of the temperature-sensitive adsorption layer at 37°C is 20-1000 N / m.
5. The orthodontic appliance according to at least one of claims 1-4, characterized in that, The method for preparing the orthodontic appliance includes the following steps: applying a solution to at least a portion of the surface of the wrapping layer near the teeth, and then curing it to form a temperature-sensitive adsorption layer; wherein the solution includes the material and solvent of the temperature-sensitive adsorption layer.
6. The orthodontic appliance according to at least one of claims 1-5, characterized in that, The orthodontic appliance is selected from one or more of the following conditions: (a) The coating is applied by brushing, spraying, spin coating or dip coating; (b) The solvent is water; (c) In the solution, the mass concentration of the material of the temperature-sensitive adsorption layer is preferably 1%-20%, for example, 10%; (d) The curing process is performed by heating; The curing temperature is preferably 20-80°C, for example, 40°C; The curing time is preferably 1-72 hours, for example, 24 hours.
7. The orthodontic appliance according to at least one of claims 1-6, characterized in that, The coating layer is prepared by compression molding, 3D printing technology or CNC machine tool cutting technology.
8. The orthodontic appliance according to at least one of claims 1-7, characterized in that, The orthodontic appliance is selected from one or more of the following conditions: (a) At least a portion of the cavity structure is fitted to the corresponding teeth; (b) The wrapping layer is a single-layer structure or a multi-layer structure; (c) The temperature-sensitive adsorption layer is disposed on the entire surface of the coating layer on the side closest to the teeth; (d) The material of the encapsulation layer is a polymer material.
9. The orthodontic appliance according to at least one of claims 1-8, characterized in that, The orthodontic appliance is selected from one or more of the following conditions: (a) The thickness ratio of the temperature-sensitive adsorption layer to the coating layer is 1:(5-40), preferably 1:(5-20), for example 1:7.5, 1:12.5, 1:18.8 or 1:37.5; The thickness of the temperature-sensitive adsorption layer is preferably 20-100 μm, and more preferably 60-100 μm. (b) The thickness of the temperature-sensitive adsorption layer below LCST is less than 200 μm.
10. The use of an orthodontic appliance as described in any one of claims 1-9 in orthodontic treatment.
11. A dental instrument, characterized in that, The dental instrument includes a housing and a cavity. The housing includes a wrapping layer and a temperature-sensitive adhesive layer. The cavity formed by the wrapping layer is used to accommodate a tooth. The temperature-sensitive adhesive layer is disposed in at least a portion of the surface of the wrapping layer near the tooth. The material of the temperature-sensitive adhesive layer includes a temperature-sensitive crystalline polymer.
12. The dental instrument as claimed in claim 11, characterized in that, The thermosensitive crystalline polymer includes polyacrylate; The structural formula of the polyacrylate is shown in Formula I, where n is an integer from 50 to 500 and X is an integer from 2 to 20. Preferably, the monomers of the polyacrylate include acrylates; preferably, the monomers of the polyacrylate include octadecyl acrylate and tetradecyl acrylate; preferably, the molar ratio of octadecyl acrylate to tetradecyl acrylate is 1:(0.1-10), for example, 1:1; preferably, the molar ratio of octadecyl acrylate to the monomers of the polyacrylate is 40%-60%.
13. The dental instrument as claimed in claim 11 or 12, characterized in that, The dental instruments are selected from one or more of the following conditions: (a) The peel strength of the temperature-sensitive adhesive layer in the molten state is above 20 N / m; Preferably, the temperature-sensitive adhesive layer is in a molten state at a temperature of 37°C; Preferably, the temperature-sensitive adhesive layer has a peel strength of 20-1000 N / m or higher at 37°C. (b) The peel strength of the temperature-sensitive adhesive layer in the crystalline state is less than 10 N / m; Preferably, the temperature-sensitive adhesive layer is in a crystalline state at a temperature of 20°C; Preferably, the peel strength of the temperature-sensitive adhesive layer at 20°C is 1-10 N / m; (c) The crystallinity switching time of the temperature-sensitive crystalline polymer is less than 5 min; (d) The temperature range in which the crystalline phase content of the temperature-sensitive crystalline polymer changes from 30% to 70% at low temperatures is 0-60℃.
14. The dental instrument according to at least one of claims 11-13, characterized in that, The dental instruments are selected from one or more of the following conditions: (a) The material of the temperature-sensitive adhesive layer also includes a film-forming agent; Preferably, the film-forming agent includes one or more of acrylates, acrylic resins, butadiene resins, polyurethane resins, and aromatic isocyanates; Preferably, the mass ratio of the thermosensitive crystalline polymer to the film-forming agent is (0.1-20):(1-20), for example, 1:1; (b) The material of the temperature-sensitive adhesive layer also includes an emulsifier; The emulsifier preferably includes one or more of alkyl sulfates, stearates, and alkylbenzene sulfonates; Preferably, the alkyl sulfate has the general formula C0. n H 2n+1 SO4X, wherein n is selected from any integer from 1 to 20, and X is selected from sodium, magnesium, aluminum, potassium, or calcium; wherein, preferably, the alkyl sulfate is sodium dodecyl sulfate; Preferably, the alkylbenzene sulfonate has the general formula C2. n H 2n+1 C6H4SO3X, where n is any integer from 1 to 20, and X is selected from sodium, magnesium, aluminum, potassium, or calcium; Preferably, the stearate is sodium stearate; Preferably, the mass ratio of the thermosensitive crystalline polymer to the emulsifier is (0.1-20):(0.1-2), for example, 10:0.
5.
15. The dental instrument as claimed in at least one of claims 11-14, characterized in that, The dental instruments are selected from one or more of the following conditions: (a) The material of the temperature-sensitive adhesive layer also includes a crosslinking agent; Preferably, the crosslinking agent includes propoxylated neopentyl glycol diacrylate and / or N,N-methylenebisacrylamide; Preferably, the mass ratio of the thermosensitive crystalline polymer to the crosslinking agent is (0.1-20):(0.1-1); (b) The material of the temperature-sensitive adhesive layer also includes a fragrance; The fragrance agent includes one or more of menthol, geraniol acetate, and edible fruit flavorings; Preferably, the mass ratio of the thermosensitive crystalline polymer to the crosslinking agent is (0.1-20):(0.01-0.1).
16. The dental instrument as claimed in at least one of claims 11-15, characterized in that, The method for preparing the dental instrument includes the following steps: coating a solution onto at least a portion of the surface of the coating layer, and then curing it to form a temperature-sensitive adhesive layer; wherein the solution includes a material and a solvent for the temperature-sensitive adhesive layer, and the material of the temperature-sensitive adhesive layer includes a temperature-sensitive crystalline polymer; Preferably, the material of the temperature-sensitive adhesive layer further includes one or more of a film-forming agent, an emulsifier, a crosslinking agent, and a fragrance; Preferably, the mass ratio of the thermosensitive crystalline polymer to the solvent in the solution is (0.1-20):(30-90), for example, 1:
9.
17. The dental instrument as claimed in at least one of claims 11-16, characterized in that, The dental instruments are selected from one or more of the following conditions: (a) The coating is applied by brushing, spraying, spin coating or dip coating; (b) The solvent is water; (c) The curing process is performed by heating; The curing temperature is preferably 30-80°C, for example, 40°C; The curing time is preferably 1-72 hours, for example 8 hours.
18. The dental instrument as claimed in at least one of claims 11-17, characterized in that, The dental instruments are selected from one or more of the following conditions: (a) The coating layer is prepared by compression molding, 3D printing technology or CNC machine tool cutting technology; (b) The material of the encapsulation layer is a polymer material; (c) The wrapping layer is a single-layer structure or a multi-layer structure; (d) The temperature-sensitive adhesive layer is disposed over the entire surface of the wrapping layer on the side closest to the teeth; (e) At least a portion of the cavity structure and the corresponding tooth fitting arrangement.
19. The dental instrument as claimed in at least one of claims 11-18, characterized in that, The dental instruments are selected from one or more of the following conditions: (a) The thickness ratio of the temperature-sensitive adhesive layer to the coating layer is 1:(10-100), for example, 1:7.5, 1:15 or 1:30; (b) The thickness of the temperature-sensitive adhesive layer is less than 100 μm, for example, 25-100 μm; (c) The mass percentage of the thermosensitive crystalline polymer in the thermosensitive adhesive layer is 20%-80%.
20. The use of a dental instrument as described in any one of claims 11-19 in orthodontic treatment.