Correcting appliance for tooth orthodontics and correcting appliance diaphragm

Abstract

The invention provides an orthodontic appliance for tooth orthodontics and an orthodontic appliance diaphragm. The appliance comprises a shell and a cavity, the shell comprises a wrapping layer and a structural layer, the structural layer is located outside the wrapping layer, the wrapping layer is used for wrapping teeth, the inner surface of the wrapping layer makes contact with the teeth, and the wrapping layer is made of an expandable material so that the wrapping layer can expand; after the wrapping layer expands, the overall size of the cavity is smaller than that of the teeth. According to the orthodontic appliance, the phenomena of slipping and sleeve disengaging do not easily occur between the orthodontic appliance and teeth, the control effect on a tooth axis can be improved, the orthodontic force and torque applying capacity of the orthodontic appliance can be further improved, and meanwhile the orthodontic appliance can also have excellent elongation at break and tearing strength.

Description

Technical Field

[0001] The invention relates to an appliance and an appliance membrane for orthodontics. Background Art

[0002] When invisible braces are used to treat malocclusion, a series of braces with cavities that are consistent with the patient's jaw shape are formed by hot pressing using polymer film materials. The design position of each brace cavity is closer to the target position than the initial jaw position and the previous brace. When in use, the brace cavity wraps around the patient's jaw, and the deviation between the design position and the jaw position causes the brace to undergo elastic deformation, thereby generating a corrective force that moves the teeth to the target position. It can be said that the ability to apply corrective force and torque is the most critical factor in the effectiveness of invisible braces, but current invisible braces still have several deficiencies: (1) Since the shape of the brace cavity is consistent with the shape of the teeth, and the brace can only interact with the teeth through contact and compression (i.e., it can only generate pressure, not tension), when the shape of the teeth is relatively smooth, such as for canines and premolars, it is easy for the brace to slip and come off the teeth, thereby limiting the brace to apply corrective force and torque to the teeth. (2) The area of ​​the appliance corresponding to the tooth neck is closer to the impedance center of the tooth, so the force-applying ability of this area plays a key role in the control of the tooth axis. However, because this area is close to the opening of the appliance cavity, it has weaker rigidity and is more likely to deform after being subjected to force, which makes it easier to create gaps between the teeth or cause slippage, affecting the appliance's control over the tooth axis. (3) In order to assist the appliance in applying force, clinical practice generally involves bonding accessories made of light-curing resin materials to the teeth. Since accessories are smaller in size than teeth, they are more affected by the machining accuracy of the appliance. In actual applications, gaps are easily created between the accessory cavity corresponding to the appliance, greatly affecting the effectiveness of the appliance. Summary of the invention

[0003] In order to solve the problem of poor correction force and torque application ability of the orthodontic appliance in the prior art, an orthodontic appliance and an orthodontic appliance membrane are provided. The orthodontic appliance is not prone to slippage and disengagement from the tooth, can improve the control effect on the tooth axis, further improve its correction force and torque application ability, and at the same time, the orthodontic appliance can also have excellent elongation at break and tear strength.

[0004] The present invention mainly adopts the following technical solutions to solve the above technical problems:

[0005] The present invention provides an orthodontic appliance, comprising a shell and a cavity, wherein the shell comprises a wrapping layer and a structural layer, wherein the structural layer is located outside the wrapping layer, and the wrapping layer is used to wrap teeth. The inner surface of the wrapping layer is in contact with the teeth, and the material of the wrapping layer is an expandable material, so that the wrapping layer is expandable; after the wrapping layer is expanded, the overall size of the cavity is smaller than the size of the teeth.

[0006] In the present invention, a wrapping layer that can change its volume by absorbing water or by changing its volume by temperature is arranged on the inner surface of the braces. When it is a wrapping layer that can change its volume by absorbing water, the braces are worn in the mouth, and the wrapping layer quickly absorbs water and expands in the saliva environment and becomes thicker; when it is a wrapping layer that can change its volume by changing its temperature, the braces are worn in the mouth, and the wrapping layer expands and becomes thicker under the action of the body temperature in the oral cavity. After the wrapping layer becomes thicker, the size of the braces cavity that was originally the same size as the teeth becomes smaller than the size of the teeth, so that the wrapping layer will be fully squeezed with the teeth, thereby generating pre-tightening pressure. This pre-tightening pressure makes the wrapping layer fully fit with the teeth, eliminating the gap caused by deformation and process deviation. At the same time, the normal force between the inner surface of the orthodontic appliance and the teeth increases, and the friction between the two also increases. This pre-tightening pressure makes the interaction between the orthodontic appliance and the teeth more complete. At the same time, the increased friction between the two can also form a greater resultant force and torque on the teeth, enhancing the control over the teeth. The increased wrapping and friction together make it less likely for the orthodontic appliance to come off relative to the jaw when the tooth movement deviates from the design.

[0007] In the present invention, the cavity is a space formed by the inner surface of the wrapping layer, the overall size of the cavity means the volume of the cavity, and the size of the tooth means the volume of the tooth.

[0008] The structural layer in the present invention can be used to provide structural support for the orthodontic appliance and provide resilience when the orthodontic appliance is deformed.

[0009] The expandable material in the present invention means a material whose volume changes with environmental changes. The expansion rate of the expandable material means the percentage of the difference between the volume of the cavity after the expansion of the wrapping layer material and the volume of the cavity before the expansion to the volume of the cavity before the expansion.

[0010] In the present invention, the expandable material is preferably a temperature-sensitive material or a water-swellable material. The temperature-sensitive material is a material whose volume increases when the ambient temperature rises, and the water-swellable material is a material whose volume increases when the material absorbs water.

[0011] Wherein, the temperature-sensitive material is preferably a single material or a composite material.

[0012] The single material is, for example, thermal expansion sponge rubber.

[0013] The composite material is, for example, at least two of epoxy resin, polystyrene, polycaprolactone, polyurethane, racemic polylactic acid, perfluorosulfonic acid ionomer, polyethylene, polyisoprene and polyamide.

[0014] The water-swellable material is preferably one or more of polyurethane, polyamide and hydrogel, more preferably polyurethane.

[0015] Wherein, the temperature expansion rate of the temperature-sensitive material is preferably 5%-100%, more preferably 5%-20%.

[0016] The expansion rate of the water-swellable material is preferably 5%-100%, more preferably 5%-20%.

[0017] In the present invention, the material of the structural layer preferably includes one or more of PA, PETG, TPU, PC, TPE, EVA and TPV.

[0018] In the present invention, preferably, the expansion rate of the material of the wrapping layer is different at different positions. More preferably, the expansion rate of the material of the wrapping layer at the crown away from the gum is smaller than the expansion rate at the crown close to the gum; further preferably, the ratio of the expansion rate at the crown away from the gum to the expansion rate at the crown close to the gum is 1:(1-10), preferably 1:(1-3), for example 1:2. The crown away from the gum refers to the upper half of the tooth, and the crown close to the gum refers to the lower half of the tooth.

[0019] In the present invention, the elastic modulus of the structural layer and the wrapping layer is preferably (5-2.5×10 3 ): 1, more preferably (5-2.5×10 2 ):1, for example, 100:1, wherein the elastic modulus of the wrapping layer refers to the elastic modulus of the wrapping layer before expansion.

[0020] In the present invention, the thickness ratio of the structural layer to the wrapping layer is preferably (1-15):1, more preferably (1-10):1, for example, 6:1.

[0021] In the present invention, the structural layer is used to provide structural support for the orthodontic appliance and to provide resilience when the orthodontic appliance is deformed.

[0022] In the present invention, the elastic modulus of the wrapping layer is preferably 0.001-200 MPa, more preferably 0.001-10 MPa.

[0023] In the present invention, the elastic modulus of the structural layer is preferably 500-2500 MPa, more preferably 700-1600 MPa.

[0024] In the present invention, the thickness of the wrapping layer is preferably 0.005-0.5 mm, more preferably 0.005-0.3 mm.

[0025] In the present invention, the thickness of the structural layer is preferably 0.2-1.2 mm, more preferably 0.3-0.6 mm.

[0026] In the present invention, the inner surface of the wrapping layer is preferably provided with protrusions and / or grooves, and the shapes of the protrusions and / or grooves are, for example, dot-shaped, strip-shaped or circle-shaped.

[0027] In the present invention, the structural layer is a single-layer structure or a multi-layer structure; when the structural layer is a multi-layer structure, the structural layer includes N1 sub-layers, N1≥2; wherein the elastic modulus of the N1 sub-layers preferably shows a gradient decreasing trend along the direction approaching the teeth, and the gradient is preferably 0.01-10MPa / um.

[0028] Among them, when N1 is 2, the elastic modulus of the two sublayers along the direction close to the teeth is preferably (1-5):1.

[0029] In the present invention, the wrapping layer is a single-layer structure or a multi-layer structure; when the wrapping layer is a multi-layer structure, the wrapping layer includes N2 sub-layers, N2≥2; wherein the elastic modulus of the N2 sub-layers preferably shows a gradient decreasing trend along the direction approaching the teeth, and the gradient is preferably 0.01-40MPa / um.

[0030] The expansion rates of the N2 sub-layers preferably show a decreasing gradient in the direction approaching the teeth, and the gradient is preferably 0.01% / um.

[0031] Among them, when N2 is 2, the elastic modulus of the two sublayers along the direction close to the teeth is preferably (1-30):1.

[0032] In the present invention, when the structural layer and the wrapping layer are respectively configured as a multi-layer structure, the comfort of the orthodontic appliance can be improved, and the auxiliary functions of the structural layer can also be increased.

[0033] In the present invention, the preparation method of the brace preferably adopts a hot pressing film forming process, for example, it may include the following steps: compression molding the heated wrapping layer material and the structural layer material, and sequentially cooling, cutting, and post-processing to form the wrapping layer and the structural layer of the brace, respectively, to obtain the brace.

[0034] The present invention also provides a corrector membrane, which comprises a wrapping layer and a structural layer, wherein the material of the wrapping layer is an expandable material.

[0035] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0036] The reagents and raw materials used in the present invention are commercially available.

[0037] The positive and progressive effects of the present invention are:

[0038] By providing a wrapping layer with a variable volume on the inner surface of the orthodontic appliance, and arranging that after the wrapping layer expands, the overall size of the cavity is smaller than the size of the tooth, so that a pre-tightening pressure can be formed between the orthodontic appliance and the tooth, and at the same time the correction force of the orthodontic appliance is improved, and the orthodontic appliance is not easy to fall off during use.

[0039] The orthodontic appliance of the present invention also has excellent elongation at break and tear strength, and has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the structure of the orthodontic device of Examples 1-6.

[0041] Figure 2 Schematic diagram of the structure of a tooth containing the orthodontic device of Examples 1-6 before expansion.

[0042] Figure 3 Schematic diagram of the structure of a tooth containing the orthodontic device of Examples 1-6 after expansion.

[0043] The reference numerals are as follows:

[0044] 1-wrapping layer; 2-structural layer; 3-tooth; 301-tooth surface. DETAILED DESCRIPTION

[0045] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0046] Examples 1-6

[0047] The braces of Examples 1-6 are formed by a hot pressing film molding process based on a dental model, specifically as follows: the heated wrapping layer material and the structural layer material are molded, and then cooled, cut, and post-processed to form the wrapping layer and the structural layer of the braces, respectively, to obtain the braces. Among them, the structural layer materials of Examples 1-6 are all PA, and the wrapping layer material, i.e., the expandable material, is shown in Table 1 below.

[0048] The orthodontic appliance of embodiments 1-6 comprises a shell and a cavity, such as Figure 1-3 The shell includes a wrapping layer 1 and a structural layer 2, wherein the structural layer 2 is located outside the wrapping layer 1, the wrapping layer 1 is used to wrap the tooth 3, the inner surface of the wrapping layer 1 is in contact with the tooth surface 301, and the material of the wrapping layer is an expandable material, so that the wrapping layer can expand; after the wrapping layer expands, the overall size of the cavity is smaller than the size of the tooth.

[0049] Among them, the inner surface of the wrapping layer of Examples 1-6 is provided with protrusions and grooves, and the shapes of the protrusions and grooves are both point-shaped.

[0050] The parameters of the wrapping layer and the structural layer of Examples 1-6 are listed in Table 1 below:

[0051] Table 1

[0052]

[0053]

[0054] Note: “ / ” in the table means not included.

[0055] The expansion rates at different positions of Examples 1-6 are listed in Table 2 below:

[0056] Table 2

[0057]

[0058] Note: “ / ” in the table means not included.

[0059] Among them, the elastic modulus of the two sublayers of the structural layer of Example 6 shows a gradient decreasing trend along the direction close to the teeth, with a gradient of 5 MPa / um, and the elastic modulus ratio is 2.5:1; the elastic modulus of the two sublayers of the wrapping layer of Example 6 shows a gradient decreasing trend along the direction close to the teeth, with a gradient of 20 MPa / um, and the expansion rate of the two sublayers shows a gradient decreasing trend along the direction close to the teeth, with a gradient of 0.01% / um, and the elastic modulus ratio is 15:1.

[0060] Comparative Example 1

[0061] The parameters of the wrapping layer and the structural layer of the orthodontic device of Comparative Example 1 are listed in Table 1, and the expansion rate parameters of the orthodontic device of Comparative Example 1 are listed in Table 2.

[0062] Comparative Example 2

[0063] Comparative Example 2 contains only one structural layer. The parameters of the braces wrapping layer and the structural layer of Comparative Example 2 are listed in Table 1. The expansion rate parameters of the braces of Comparative Example 2 are listed in Table 2.

[0064] Effect Example 1

[0065] Elongation at break test: The tensile toughness test was performed on the orthodontic appliances of Examples 1-6 and Comparative Examples 1 and 2, and the test method was in accordance with the method of "GB / T 1040.3 2006 Determination of tensile properties of plastics", and the equipment tensile speed was set to 50 mm / min. Type 5 specimens were used.

[0066] Tear strength test: The tear strength test was carried out on the orthodontic appliances of Examples 1-6 and Comparative Examples 1 and 2. The test method was in accordance with Method B and Experimental Procedure (a) of GB / T 529-2008 Determination of Tear Strength of Vulcanized Rubber or Thermoplastic Rubber, wherein the sample was prepared in accordance with 5.1.2 of the standard, the sample thickness was based on the actual thickness of the product, and the tensile speed was 200±10 mm / min.

Claims

1. An appliance for orthodontics, comprising a shell and a cavity, wherein the shell comprises a wrapping layer and a structural layer, wherein the structural layer is located outside the wrapping layer, the wrapping layer is used to wrap teeth, and the inner surface of the wrapping layer is in contact with the teeth, characterized in that: The material of the wrapping layer is an expandable material, so that the wrapping layer can expand; after the wrapping layer expands, the overall size of the cavity is smaller than the size of the tooth.

2. The orthodontic appliance according to claim 1, characterized in that: The expandable material is a temperature-sensitive material or a water-swellable material.

3. The orthodontic appliance according to claim 2, characterized in that: The temperature-sensitive material is a single material or a composite material; Wherein, the single material is, for example, heat-expandable sponge rubber; Wherein, the composite material is, for example, at least two of epoxy resin, polystyrene, polycaprolactone, polyurethane, racemic polylactic acid, perfluorosulfonic acid ionomer, polyethylene, polyisoprene and polyamide; And / or, the water-swellable material is one or more of polyurethane, polyamide and hydrogel, preferably polyurethane; And / or, the expansion rate of the temperature-sensitive material is 5%-100%, preferably 5%-20%; And / or, the expansion rate of the water-swellable material is 5%-100%, preferably 5%-20%.

4. The orthodontic appliance according to claim 1, characterized in that: The material of the wrapping layer has different expansion rates at different locations; Preferably, the expansion rate of the material of the wrapping layer at the crown away from the gum is smaller than that at the crown close to the gum; wherein the crown away from the gum refers to the upper half of the tooth, and the crown close to the gum refers to the lower half of the tooth; More preferably, the ratio of the expansion rate of the crown far from the gum to the expansion rate of the crown close to the gum is 1:(1-10), preferably 1:(1-3), for example 1:

2.

5. The orthodontic appliance according to claim 1, characterized in that: The elastic modulus ratio of the structural layer to the wrapping layer is (5-2.5×10 3 ): 1, preferably (5-2.5×10 2 ): 1, for example, 100: 1; wherein the elastic modulus of the wrapping layer refers to the elastic modulus of the wrapping layer before expansion; And / or, the elastic modulus of the wrapping layer is 0.001-200 MPa, preferably 0.001-10 MPa; And / or, the elastic modulus of the structural layer is 500-2500 MPa, preferably 700-1600 MPa.

6. The orthodontic appliance according to claim 1, characterized in that: The thickness ratio of the structural layer to the wrapping layer is (1-15):1, preferably (1-10):1, for example, 6:1; And / or, the thickness of the wrapping layer is 0.005-0.5 mm, preferably 0.005-0.3 mm; And / or, the thickness of the structural layer is 0.2-1.2 mm, preferably 0.3-0.6 mm.

7. The orthodontic appliance according to claim 1, characterized in that: The inner surface of the wrapping layer is provided with protrusions and / or grooves, and the shapes of the protrusions and / or grooves are, for example, dot-shaped, strip-shaped or circle-shaped.

8. The orthodontic appliance according to claim 1, characterized in that: The structural layer is a single-layer structure or a multi-layer structure; When the structural layer is a multi-layer structure, the structural layer includes N1 sub-layers, N1≥2; wherein the elastic modulus of the N1 sub-layers preferably decreases gradually along the direction close to the teeth, and the gradient is preferably 0.01-10 MPa / um; Among them, when N1 is 2, the elastic modulus of the two sublayers along the direction close to the teeth is preferably (1-5):

1.

9. The orthodontic appliance according to claim 1, characterized in that: The wrapping layer is a single-layer structure or a multi-layer structure; When the wrapping layer is a multi-layer structure, the wrapping layer includes N2 sub-layers, N2≥2; wherein the elastic modulus of the N2 sub-layers preferably decreases gradually along the direction close to the teeth, and the gradient is preferably 0.01-40 MPa / um; The expansion rate of the N2 sub-layers preferably shows a gradient decreasing trend along the direction close to the teeth, and the gradient is preferably 0.01% / um; Among them, when N2 is 2, the elastic modulus of the two sublayers along the direction close to the teeth is preferably (1-30):

1.

10. A corrective device membrane, characterized in that: The invention comprises a wrapping layer and a structural layer, wherein the wrapping layer is made of expandable material.

Images