Multifunctional composite resin disc and preparation method thereof

Abstract

The invention discloses a multifunctional composite resin disc and a preparation method thereof. The multifunctional composite resin disc comprises an upper soft lining layer, a middle transition layer and a lower hard wear-resistant layer of which the hardness is gradually increased from top to bottom, the upper soft lining layer is composed of a modified acrylate elastomer, and the upper soft lining layer comprises polyethyl methacrylate, ethyl methacrylate, methyl methacrylate, polyester fibers, silica powder and pigment; the middle transition layer comprises polymethyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate and pigment; the lower hard wear-resistant layer is prepared from polymethyl methacrylate, methyl methacrylate, prepolymerized filler, ethylene glycol dimethacrylate and pigment. The flexible denture is provided with the soft lining layer and has good adaptive capacity in the oral cavity, and a doctor does not need to additionally adopt materials such as silicone rubber to manufacture the soft lining layer, so that the problem of pressing pain or instability when the flexible denture is worn is solved, and meanwhile, the hardness and the wear resistance of the materials can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of dental restorative materials technology, and in particular to a multifunctional composite resin disc and its preparation method. Background Technology

[0002] Currently, the most common resin discs for removable dentures manufactured using CAD / CAM technology are polymethyl methacrylate (PMMA) and methyl methacrylate (MMA). After digital design and fabrication of the prosthesis, patients face two key issues when wearing dentures made of these materials.

[0003] Firstly, after wearing dentures, patients may experience instability or tenderness in the oral cavity. This may be due to a mismatch between the shape, size, position, or other factors of the denture and the patient's oral structure, resulting in uneven pressure distribution and increasing the likelihood of pain. Polymethyl methacrylate (PMMA) is a hard material and does not possess the property of adapting to the oral structure. In this case, the dentist needs to select a soft material, such as a silicone rubber liner, to cover and adhere to the prepared PMMA restoration tissue surface. This improves the comfort of the denture, makes it conform to the patient's oral structure, reduces tenderness and discomfort, improves the retention and stability of the denture, and thus solves the problems of tenderness or instability. This procedure is relatively complex, involves long waiting times for patients, is costly, and requires multiple chairside procedures by the dentist, such as polishing, and requires the operation and use of different materials. It cannot be solved by a single consumable.

[0004] Secondly, the material has poor wear resistance. When polymethyl methacrylate is subjected to biting force, it will be continuously worn down, causing the occlusal surface to gradually flatten, which in turn reduces chewing efficiency and shortens the lifespan of the denture.

[0005] Furthermore, some product solutions in the industry propose multi-layered designs with varying hardness and softness. However, there are significant differences between the different layers in terms of materials and performance. This is particularly true for the upper layer (dentin-like layer) and lower layer (enamel-like layer) of artificial tooth color. The upper layer primarily uses acrylic material, while the lower layer is a composite resin material. These two materials differ significantly in polymerization methods and surface properties. The upper acrylic material is mainly polymerized through free radicals, with stable carbon-carbon bonds connecting the molecular chains. The lower composite resin material is a mixture of polyurethane dimethacrylate, fillers, triethylene glycol dimethacrylate, etc., and its polymerization system has poor compatibility with acrylic acid, making it difficult to form covalent bonds. Moreover, due to the different surface properties of the two materials, gaps may appear at the contact surface, preventing a tight molecular-level bond. During use, the upper and lower layers are prone to peeling and detachment, and the lower layer is more susceptible to staining, resulting in uneven color and poor aesthetics in the restoration. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a multifunctional composite resin disc and its preparation method. This invention provides a resin disc with a built-in soft lining and a high-hardness wear-resistant layer. The tissue surface of the removable denture prepared using this resin disc has a built-in soft lining and good intraoral self-adaptation ability. Doctors do not need to use additional materials such as silicone rubber to make a soft lining, thereby solving the problem of pressure pain or instability when wearing removable dentures.

[0007] To achieve the above objectives, the present invention provides a multifunctional composite resin disc, comprising an upper soft liner, a middle transition layer, and a lower hard wear-resistant layer, with the hardness gradually increasing from top to bottom.

[0008] The upper soft liner is made of modified acrylic elastomer.

[0009] The upper soft liner includes polyethyl methacrylate, ethyl methacrylate, methyl methacrylate, polyester fiber, silica powder, and pigments.

[0010] The intermediate transition layer includes polymethyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate, and pigments.

[0011] The lower hard wear-resistant layer includes polymethyl methacrylate, methyl methacrylate, prepolymerized filler, ethylene glycol dimethacrylate, and pigment.

[0012] Furthermore, the upper soft liner accounts for 45-60% of the total volume, the middle transition layer accounts for 10-25% of the total volume, and the lower hard wear-resistant layer accounts for 20-35% of the total volume.

[0013] Furthermore, the upper soft liner comprises, by weight percentage, 40-60% polymethyl methacrylate, 20-35% ethyl methacrylate, 10-15% methyl methacrylate, 0.05%-0.2% polyester fiber, 1-3% silica powder, and 0.001-0.3% pigment.

[0014] Furthermore, the intermediate transition layer comprises, by weight percentage, 45-70% polymethyl methacrylate, 23.7-35% methyl methacrylate, 1.5-6% ethylene glycol dimethacrylate, and 0.001-0.3% pigment.

[0015] Furthermore, the lower hard wear-resistant layer comprises, by weight percentage, 15-30% polymethyl methacrylate, 20-35% methyl methacrylate, 30-55% prepolymerized filler, 1.5-6% ethylene glycol dimethacrylate, and 0.001-0.3% pigment.

[0016] Furthermore, the prepolymerized filler includes silica filler, polyurethane dimethacrylate, and benzoyl peroxide.

[0017] Furthermore, the mass ratio of the silica filler to the polyurethane dimethacrylate is 1.5:2, and the benzoyl peroxide accounts for 1% of the total mass of the prepolymerized filler.

[0018] This invention also provides a method for preparing a multifunctional composite resin disc, comprising the following steps:

[0019] S1. Raw material preparation: Prepare prepolymerized filler and provide the powdered solid raw materials and liquid raw materials required for each layer, wherein the powdered solid raw materials need to be dried.

[0020] S2. Batching and mixing: According to the composition ratio of the upper soft liner, the middle transition layer and the lower hard wear-resistant layer, the required powdered solid raw materials for each layer are weighed and mixed to obtain the required powder mixture for each layer. Then, the powder mixture of each layer is mixed and stirred with the liquid raw materials of each layer to obtain the initial material of each layer.

[0021] S3. Using a mold with a preset thickness and diameter, the soft liner, transition layer and hard wear-resistant layer are pre-pressed with pressures ranging from 3MPa to 7MPa to make them blanks with a specific thickness.

[0022] S4. Freezing the blank material makes the surface of the blank harder.

[0023] S5. Subsequently, the three-layer frozen blanks are stacked in the order of top, middle and bottom, and then cured and molded in one go. During the curing process, the structures between each layer are chemically bonded by methyl methacrylate molecules, thus achieving integration.

[0024] S6. Finally, heat treatment is performed to further promote curing and eliminate internal stress, resulting in the final multifunctional composite resin disc.

[0025] Furthermore, the preparation of the prepolymerized filler includes the following steps:

[0026] Select silica filler and mix it with polyurethane dimethacrylate at a mass ratio of 1.5:2, and add a small amount of benzoyl peroxide, which accounts for 1% of the total mass.

[0027] The mixed slurry was stirred and vacuumed simultaneously. The pressure was set to 80kPa-95kPa, the time was set to 45min, and the mixer speed was set to 20r / min. Then the mixed and vacuumed slurry was poured into a stainless steel tray and placed into a curing box.

[0028] The curing chamber temperature is set to 95℃±5℃, and the curing time is 50min, thus forming a cured blank. The blank is then crushed and ground using zirconia spherical abrasives at a speed of 15r / min for 36h. The ground powder is then sieved to ensure that the maximum particle size does not exceed 125μm. Small particle size ensures a finer surface for the product and effectively improves its resistance to staining.

[0029] Furthermore, the silica filler is first subjected to silanization treatment, and silica filler with a surface area between 80 and 200 m² / g is mixed with polyurethane dimethacrylate.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] This invention enables removable dentures to better adapt to the oral environment during wear, reducing tissue surface pressure pain or instability caused by hard materials. The removable dentures made with this resin plate have a soft lining on the tissue surface, which has good intraoral self-adaptation ability. Doctors do not need to use additional materials such as silicone rubber to make a soft lining, thus solving the problem of pressure pain or instability when wearing removable dentures.

[0032] Compared to existing products, the resin disc provided by this patent offers significant improvements in comfort and durability. Through a unique process design, using methacrylic resin as the "adhesive" between different layers, the materials at different layers exhibit a gradual change in hardness while possessing a more stable chemical structure and consistent stain resistance, truly achieving a "multi-functional integrated design." Removable dentures made using this product are more stable, with less likelihood of peeling or falling off between different layers, or color differences due to varying stain resistance, providing a superior material choice for the fabrication of removable dentures.

[0033] The filler used in this invention differs from the silica that is readily available and usable on the market. Silica prepared by conventional siliconization technology is incompatible with materials such as polymethyl methacrylate, which will significantly reduce the transparency of the product and form dense silica aggregates on the product surface.

[0034] The filler in this invention requires the use of polyurethane dimethacrylate-mediated pre-curing-functional filler microsphere preparation technology for raw material preparation. The treated material can be used together with polymethyl methacrylate without significantly reducing transparency, while having excellent compatibility and significantly improving the hardness and wear resistance of the material.

[0035] This invention utilizes a unique raw material preparation technology to perfectly fuse polyethyl methacrylate (PEM) with polymethyl methacrylate (MMA) filler and MMA material, ensuring both the high hardness and wear resistance of the resin disc and giving it a soft lining function. Attached Figure Description

[0036] To more clearly illustrate the technology in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic flowchart of a method for preparing a multifunctional composite resin disc according to Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram showing the anti-staining experiment comparison of the present invention. Detailed Implementation

[0039] The technology of this embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiment is one embodiment of the present invention, and not all embodiments thereof. Based on this embodiment of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0041] Furthermore, if the embodiments of the present invention involve descriptions such as "first" or "second", such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0042] This invention provides a multifunctional composite resin disc, comprising an upper soft liner, a middle transition layer, and a lower hard wear-resistant layer, with the hardness gradually increasing from top to bottom. The upper soft liner has excellent intraoral self-adaptability, eliminating the need for dentists to use additional materials such as silicone rubber to create a soft liner, thus solving the problems of pressure pain or instability that occur when wearing removable dentures. The lower hard wear-resistant layer constitutes the highly wear-resistant occlusal surface of the removable denture, reducing wear and extending the lifespan of the denture. Therefore, the preferred hardness of the upper soft liner in this invention is 5HV0.2, 6HV0.2, 7HV0.2, 8HV0.2, or 9HV0.2. Alternatively, the hardness can be set to 10HV0.2, depending on the actual situation. The key is to ensure the hardness of the upper soft liner is controlled within the range of 5HV0.2 to 10HV0.2. Similarly, the hardness of the middle transition layer can be 18HV0.2, 19HV0.2, 20HV0.2, 21HV0.2, 22HV0.2, or 23HV0.2, depending on the actual situation. The key is to ensure the hardness of the middle transition layer is controlled within the range of 18HV0.2 to 23HV0.2. The hardness of the lower hard wear-resistant layer can be 26HV0.2, 28HV0.2, 30HV0.2, 34HV0.2, or 36HV0.2. Alternatively, the hardness can be set to 40HV0.2, depending on the actual situation. The key is to ensure the hardness of the lower hard wear-resistant layer is controlled within the range of 26HV0.2 to 40HV0.2, thus creating a gradually increasing hardness. The upper soft liner occupies 45-60% of the total volume, such as 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. The middle transition layer occupies 10-25% of the total volume, such as 10%, 11%, or 12%. %, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 25%; the lower hard wear-resistant layer accounts for 20-35% of the total volume, such as 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34% or 35% of the total volume; this structural design ensures both the flexibility and fit of the resin disc when in contact with the oral cavity, and also ensures the overall structural support strength and wear resistance.

[0043] In this invention, the upper soft liner layer comprises polyethyl methacrylate, ethyl methacrylate, methyl methacrylate, polyester fiber, silica powder, and pigment. Specifically, by mass percentage, it comprises 40-70% polyethyl methacrylate, 20-35% ethyl methacrylate, 10-15% methyl methacrylate, 0.05-0.2% polyester fiber, 1-3% silica powder, and 0.001-0.3% pigment. Preferably, the polyethyl methacrylate content can be set to 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, and 68%. The composition includes 69% or 70% ethyl methacrylate (which can be set to 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, or 35%), methyl methacrylate (which can be set to 10%, 11%, 12%, 13%, 14%, or 15%), polyester fiber (which can be set to 0.05%, 0.1%, 0.08%, 0.12%, 0.15%, 0.18%, or 0.2%), silica powder (which can be set to 1%, 1.5%, 2%, 2.5%, or 3%), and pigment (which can be set to 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, or 0.3%). After uniform mixing of all components, a soft lining material with good elasticity and biocompatibility is formed.

[0044] The intermediate transition layer comprises polymethyl methacrylate (PMMA), methyl methacrylate (MMA), ethylene glycol dimethacrylate (EDM), and pigment. Specifically, by mass percentage, it comprises 45-60% PMMA, 23.7-35% MMA, 1.5-6% EDM, and 0.001-0.3% pigment. Preferably, the PMMA content can be set to 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%, and the MMA content can be set to 2%. The components can be 3.7%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, or 35%; ethylene glycol dimethacrylate can be set to 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, or 6%; and pigments can be set to 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, or 0.3%. After thorough mixing, a transition layer structure with high mechanical strength and good dimensional stability is formed, effectively improving the interlayer bonding and durability of the overall material.

[0045] The lower hard wear-resistant layer comprises polymethyl methacrylate (PMMA), methyl methacrylate (MMA), prepolymerized filler, ethylene glycol dimethacrylate (EDGD), and pigment. Specifically, by mass percentage, it comprises 15-30% PMMA, 20-35% MMA, 30-55% prepolymerized filler, 1.5-6% EGD, and 0.001-0.3% pigment. Preferably, the PMMA content can be set to 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, and the MMA content can be set to 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, or 30%. The prepolymer filler can be set to 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, or 55%, and the ethylene glycol dimethacrylate can be set to 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, or 6%. The pigment can be set to 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, or 0.3%. This layer significantly improves surface hardness and scratch resistance through the dense packing of the prepolymer filler, while maintaining good gloss and color stability, ensuring that the material still has excellent wear resistance and appearance retention under long-term use conditions.

[0046] In this embodiment, the prepolymerized filler includes silica filler, polyurethane dimethacrylate, and benzoyl peroxide. Preferably, the silica filler is silanized, and the surface area of ​​the silica filler is controlled between 80 and 200 m² / g. The silanized silica filler and polyurethane dimethacrylate form a stable crosslinked network under the action of a peroxide initiator, which further enhances the interfacial bonding force between the filler and the matrix resin and effectively inhibits the propagation of microcracks. Preferably, the mass ratio of silica filler to polyurethane dimethacrylate is 1.5:2, and the benzoyl peroxide accounts for 1% of the total mass of the prepolymerized filler.

[0047] like Figure 1 As shown, the present invention also provides a method for preparing a multifunctional composite resin disc, comprising the following steps:

[0048] S1. Raw material preparation: Prepare prepolymerized filler and provide the powdered solid raw materials and liquid raw materials required for each layer, wherein the powdered solid raw materials need to be dried;

[0049] The preparation of the prepolymerized filler in this step is as follows:

[0050] First, the silica filler is silanized. Silica filler with a surface area between 80 and 200 m² / g is selected and mixed with polyurethane dimethacrylate. Specifically, the silica filler and polyurethane dimethacrylate are mixed at a mass ratio of 1.5:2, and a small amount of benzoyl peroxide is added, accounting for 1% of the total mass.

[0051] The mixed slurry is stirred and vacuumed simultaneously. The pressure is set to 80~95kPa, the time is set to 45min, and the mixer speed is set to 20r / min. Then, the mixed and vacuumed slurry is poured into a stainless steel tray and placed in a curing chamber. The curing chamber temperature is set to 95℃±5℃ and the curing time is 50min, thus forming a cured blank.

[0052] After the raw material is crushed, it is ground using zirconia spherical abrasive. The rotation speed is set to 15 r / min and the grinding time is 36 h. The ground powder is then sieved to ensure that the maximum particle size does not exceed 125 μm. Small particle size can ensure that the product has a finer surface and effectively improve the resistance to staining.

[0053] The powder after grinding and sieving is the prepolymerized filler, which is placed in a dry environment for later use. Specifically, materials such as polyethyl methacrylate, polymethyl methacrylate, and pigments are dried. The preferred process is 75℃~90℃, and the drying time is 4~8h. The moisture content of the treated material should be less than 1%. The liquid raw materials of the remaining layers can be mixed according to the recommended ratio. The mixing time is generally 20~30min.

[0054] S2. Ingredients and Mixing: Ingredients are prepared according to the composition ratio of the upper soft liner, the middle transition layer, and the lower hard wear-resistant layer. Specifically, the upper soft liner, by weight percentage, includes 40-60% polymethyl methacrylate, 20-35% ethyl methacrylate, 10-15% methyl methacrylate, 0.05-0.2% polyester fiber, 1-3% silica fume, and 0.001-0.3% pigment; the middle transition layer, by weight percentage, includes 45-70% polymethyl methacrylate, 20-35% methyl methacrylate, 1.5-6% ethylene glycol dimethacrylate, and 0.001-0.3% pigment; the lower hard wear-resistant layer, by weight percentage, includes 15-30% polymethyl methacrylate, 20-35% methyl methacrylate, 30-55% prepolymer filler, 1.5-6% ethylene glycol dimethacrylate, and 0.001-0.3% pigment.

[0055] Next, as described in S1, the dried powdered solid raw materials and liquid raw materials of each layer are added to the mixer in sequence. First, the required powdered solid raw materials for each layer are weighed and mixed to obtain the required powder mixture for each layer.

[0056] Then, the powder mixture of each layer is mixed and stirred with the liquid raw material mixture of each layer to obtain the initial material of each layer. In this step, a double planetary mixer is preferred, and the mixing is carried out at 50 r / min. The mixing time is generally set to 50 min.

[0057] Specifically, the upper soft liner is made by first drying polyethyl methacrylate, polyester fiber, silica powder and pigment and then premixing them, then adding liquid monomers of ethyl methacrylate and methyl methacrylate, and then placing them in a double planetary mixer and stirring at 50 r / min for 50 min to ensure that the system is uniform and free of bubbles.

[0058] Similarly, the middle transition layer is made by premixing polymethyl methacrylate and pigment after drying, then adding liquid monomers of methyl methacrylate and ethylene glycol dimethacrylate, and stirring in a double planetary mixer at 50 r / min for 50 min until uniform and free of bubbles.

[0059] The lower hard wear-resistant layer is made by premixing polymethyl methacrylate, prepolymerized filler, and pigment after drying, and then adding liquid monomers of methyl methacrylate and ethylene glycol dimethacrylate. The mixture is stirred for 50 minutes at 50 rpm using a double planetary mixer to ensure that the system is fully homogenized and free of air bubbles.

[0060] After each layer of materials is prepared, it should be put into use as soon as possible to avoid moisture absorption affecting performance.

[0061] S3. Using a mold with preset thickness and diameter, pre-press the soft liner, transition layer, and hard wear-resistant layer with a pressure of 3~7MPa to make them blanks with specific thicknesses. It is recommended that the upper soft liner account for 45~60% of the total volume, the middle transition layer account for 10~25% of the total volume, and the lower hard wear-resistant layer account for 20~35% of the total volume. If a resin disc with a diameter of 98mm and a thickness of 30mm is to be made, the upper soft liner thickness can be designed to be 15mm, the middle transition layer to be 6mm, and the lower hard wear-resistant layer to be 9mm. The specific thickness distribution can be adjusted within the recommended range.

[0062] S4. Freeze the raw material to make its surface more rigid;

[0063] Specifically, the pre-pressed blank is placed in a refrigerator at a temperature of -22℃±5℃ and frozen for 48 hours to make the surface of the blank more rigid.

[0064] S5. Subsequently, the three-layer frozen blanks are stacked in the order of top, middle and bottom, and then cured and molded at a temperature of 125℃±5℃ in one go. During the curing process, the structure between each layer is chemically bonded by methyl methacrylate molecules, thus achieving integration.

[0065] S6. Finally, heat treatment is performed to further promote curing and eliminate internal stress. The preferred heat treatment process is 100℃±2℃ for 6 hours to obtain the final multifunctional composite resin disc, which can then be encapsulated.

[0066] Example 1

[0067] In this embodiment 1, the upper soft liner layer, by weight percentage, comprises 60% polymethyl methacrylate, 26% ethyl methacrylate, 12.8% methyl methacrylate, 0.1% polyester fiber, 1% silica powder, and 0.1% pigment; the middle transition layer, by weight percentage, comprises 67.9% polymethyl methacrylate, 30% methyl methacrylate, 2% ethylene glycol dimethacrylate, and 0.1% pigment; the lower hard wear-resistant layer, by weight percentage, comprises 28% polymethyl methacrylate, 29.9% methyl methacrylate, 40% prepolymerized filler, 2% ethylene glycol dimethacrylate, and 0.1% pigment; a multifunctional composite resin disc is prepared by the above preparation method.

[0068] Example 2

[0069] In this Example 2, the lower hard wear-resistant layer, by weight percentage, includes 30% polymethyl methacrylate, 35% methyl methacrylate, 30% prepolymer filler, 4.9% ethylene glycol dimethacrylate, and 0.1% pigment, with the remainder being the same as in Example 1.

[0070] Example 3

[0071] In this Example 3, the lower hard wear-resistant layer, by mass percentage, includes 15% polymethyl methacrylate, 22.9% methyl methacrylate, 60% prepolymer filler, 2% ethylene glycol dimethacrylate, and 0.1% pigment, with the remainder being the same as in Example 1.

[0072] Example 4

[0073] In this Example 4, the lower hard wear-resistant layer, by mass percentage, includes 23% polymethyl methacrylate, 24.9% methyl methacrylate, 50% prepolymer filler, 2% ethylene glycol dimethacrylate, and 0.1% pigment, with the remainder being the same as in Example 1.

[0074] Example 5

[0075] In this Example 5, the lower hard wear-resistant layer, by mass percentage, includes 30% polymethyl methacrylate, 20% methyl methacrylate, 48% prepolymer filler, 1.9% ethylene glycol dimethacrylate, and 0.1% pigment, with the remainder being the same as in Example 1.

[0076] Example 6

[0077] In this Example 6, the upper soft liner, by weight percentage, includes 60% polyethyl methacrylate, 28.8% ethyl methacrylate, 10% methyl methacrylate, 0.1% polyester fiber, 1% silica powder, and 0.1% pigment. The rest are the same as in Example 1.

[0078] Example 7

[0079] In this Example 7, the upper soft liner comprises, by weight percentage, 60% polymethyl methacrylate, 23.8% ethyl methacrylate, 15% methyl methacrylate, 0.1% polyester fiber, 1% silica powder, and 0.1% pigment, with the remainder being the same as in Example 1.

[0080] Example 8

[0081] In this Example 8, the middle transition layer, by mass percentage, includes 70% polymethyl methacrylate, 23.7% methyl methacrylate, 6% ethylene glycol dimethacrylate, and 0.3% pigment, with the remainder being the same as in Example 1.

[0082] Example 9

[0083] In this Example 9, the middle transition layer, by mass percentage, includes 62.9% polymethyl methacrylate, 35% methyl methacrylate, 2% ethylene glycol dimethacrylate, and 2% pigment, with the remainder being the same as in Example 1.

[0084] Example 10

[0085] In this Example 10, the middle transition layer, by mass percentage, includes 69% polymethyl methacrylate, 25% methyl methacrylate, 5.9% ethylene glycol dimethacrylate, and 0.1% pigment; the rest are the same as in Example 1.

[0086] Comparative Example 1

[0087] Currently, widely used resin discs typically consist of two parts: an upper layer (dentin-like layer) and a lower layer (enamel-like layer) with an artificial tooth color. The upper layer is often made of acrylic materials to simulate the color and texture of natural dentin. The lower layer is mainly composed of composite resin materials. Typical components of this type of composite resin include resin matrices such as bisphenol A glycerol dimethacrylate (Bis-GMA), urethane dimethacrylate (UDMA), and triethylene glycol dimethacrylate (TEGDMA), along with inorganic fillers such as silica and barium glass powder to improve the material's mechanical properties and aesthetics. However, this widely used composite resin technology has some significant shortcomings in practical applications. Its main drawbacks are poor stain resistance, making it prone to staining by pigments from daily diet. Furthermore, its bonding with the upper acrylic material is not ideal, exhibiting weak interfacial adhesion and a tendency to delamination or detachment.

[0088] like Figure 1 As shown in the table below, the anti-staining effect of Comparative Example 1 and Example 1 was compared by immersion in a simulated 100°C environment for 4 hours. The test results show that the surface of the resin disc in Comparative Example 1 showed obvious discoloration after immersion.

[0089]

[0090] Table 1

[0091] From the table above and appendix Figure 2 It can be seen that in the anti-staining experiment of Example 1, the initial color was used as the original control group. Then, the upper soft liner, middle transition layer and lower hard wear-resistant layer of Example 1, and the composite resin material of Comparative Example 1 were immersed in 0.1% curry, strong tea, soy sauce and coffee at 100°C for 4 hours for staining detection. Combined with Table 1 and Figure 2 It can be seen that, regardless of whether it is 0.1% curry, strong tea, soy sauce, or coffee, the upper soft lining layer, the middle transition layer, and the lower hard wear-resistant layer in Example 1 all exhibit superior stain resistance compared to the existing composite resin material in Comparative Example 1. Therefore, it can be determined that the composite resin disc of the present invention has a significantly improved stain resistance compared to the prior art. Especially when facing a 0.1% curry solution, the color difference values ​​of each layer in Example 1 are all below Δ2.00, while those in Comparative Example 1 reach Δ39.70, showing a very significant difference. This indicates that the present invention, through its layered structural design and specific component control, effectively blocks the penetration of external pigments, greatly enhancing the aesthetic stability of the material under long-term use, and possessing outstanding practical value and technological advancement.

[0092] As shown in Table 2, the lower hard wear-resistant layer in Comparative Example 1 and Examples 1 to 4 exhibits wear resistance testing:

[0093]

[0094] Table 2

[0095] As can be seen from Table 2 above, in the wear resistance test of Example 1,

[0096] After 500 cycles of friction in an abrasion tester, the lower hard wear-resistant layers of Examples 1 to 4 showed significantly better surface roughness (Ra 1.063) than Comparative Example 1, with the filler content increasing from 30% to 60% in Examples 1-4. Furthermore, the surface roughness of Examples 1 (0.338, 0.279, 0.230, and 0.258, respectively) was significantly better than that of Comparative Example 1 (Ra 0.063). The hardness test value remained above 30HV 0.2, significantly better than the Comparative Example without this material. The data indicate that by introducing prepolymerized fillers and a synergistic crosslinking structure, the deformation resistance and wear resistance of the material surface are effectively improved. Especially under continuous friction conditions, it maintains low roughness and high gloss stability, further confirming the innovative significance of this invention in terms of mechanical durability.

[0097] Table 3 shows the adhesion strength test results for each layer in Comparative Example 1 and Examples 1 to 10. The test was conducted using the shear bond strength method, with units of MPa, following the test method in the YY / T0518 standard, under conditions of 50% ± 5% humidity and 23℃ ± 2℃.

[0098]

[0099] Table 3

[0100] As can be clearly seen from the table above, the content of methyl methacrylate material in Examples 1 and 6 gradually increases in the upper soft liner, and its shear bonding ability also gradually increases. In the middle transition layer, the content of methyl methacrylate material in Examples 8 and 9 gradually increases, significantly improving the interlayer bonding strength. The measured adhesion force gradually increases from less than 40 MPa in Comparative Example 1 to more than 70 MPa in Example 10, indicating that the gradient crosslinking design effectively alleviates stress concentration and enhances interface stability. Similarly, the content of methyl methacrylate material in the lower wear-resistant layer gradually increases, significantly improving the bonding force between the wear-resistant layer and the substrate. The measured peel strength is nearly twice that of Comparative Example 1. After high temperature and high humidity aging test (85℃ / 85%RH, 500h), each example still maintains an initial adhesion force of more than 70 MPa, while Comparative Example 1 drops to less than 20 MPa, further verifying the durability advantage of the gradient structure in complex environments.

[0101] In summary, this invention requires the addition of methyl methacrylate (MMA) in specific proportions to the upper soft liner, the middle transition layer, and the lower wear-resistant layer. This material, acting as a crucial connecting link between the layers, effectively promotes the interaction between different structures through its unique chemical activity, achieving a stable chemical bond. This approach not only strengthens the adhesion between layers but also significantly improves the overall structural stability and durability, ultimately integrating three layers of materials with different functions into a uniform, continuous, and high-performance whole.

[0102] To significantly improve the physical properties of the underlying hard wear-resistant layer, a prepolymerized filler was innovatively developed as a reinforcing material. Compared to traditional fillers, the prepolymerized filler can more effectively combine with the acrylic resin matrix, achieving good interfacial compatibility and dispersibility. This improvement not only retains the high transparency inherent in acrylic materials but also further enhances the surface hardness and mechanical strength of the material. Simultaneously, the addition of the prepolymerized filler also endows the composite layer with excellent anti-staining properties, effectively resisting the penetration of various colored substances during practical use, thereby extending the material's service life and maintaining its aesthetic appeal.

[0103] The prepolymer filler of this invention is prepared using silica filler with a specific surface area, strictly controlled within the range of 80–200 m² / g. This filler is thoroughly mixed with polyurethane dimethacrylate at a precise mass ratio of 1.5:2 to ensure the uniformity and stability of the material properties. Furthermore, a small amount of benzoyl peroxide is added as an initiator, strictly controlled to 1% of the total mixed mass. After mixing, the material undergoes a thermal polymerization reaction to achieve initial solidification, followed by mechanical crushing and fine grinding to achieve the required particle size. Finally, a sieving process yields a prepolymer filler product that meets the specifications.

[0104] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multifunctional composite resin disc, characterized in that, It includes an upper soft liner, a middle transition layer, and a lower hard wear-resistant layer, with the hardness gradually increasing from top to bottom. The upper soft liner includes polyethyl methacrylate, ethyl methacrylate, methyl methacrylate, polyester fiber, silica powder, and pigments; The intermediate transition layer includes polymethyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate, and pigments; The lower hard wear-resistant layer includes polymethyl methacrylate, methyl methacrylate, prepolymerized filler, ethylene glycol dimethacrylate, and pigment.

2. The multifunctional composite resin disc according to claim 1, characterized in that, The upper soft lining layer accounts for 45-60% of the total volume, the middle transition layer accounts for 10-25% of the total volume, and the lower hard wear-resistant layer accounts for 20-35% of the total volume.

3. The multifunctional composite resin disc according to claim 1, characterized in that, The upper soft liner comprises, by weight percentage, 40-60% polyethyl methacrylate, 20-35% ethyl methacrylate, 10-15% methyl methacrylate, 0.05-0.2% polyester fiber, 1-3% silica powder, and 0.001-0.3% pigment.

4. The multifunctional composite resin disc according to claim 1, characterized in that, The intermediate transition layer comprises, by weight percentage, 45-70% polymethyl methacrylate, 23.7-35% methyl methacrylate, 1.5-6% ethylene glycol dimethacrylate, and 0.001-0.3% pigment.

5. A multifunctional composite resin disc according to claim 1, characterized in that, The lower hard wear-resistant layer comprises, by weight percentage, 15-30% polymethyl methacrylate, 20-35% methyl methacrylate, 30-55% prepolymer filler, 1.5-6% ethylene glycol dimethacrylate, and 0.001-0.3% pigment.

6. A multifunctional composite resin disc according to claim 5, characterized in that, The prepolymerized filler includes silica filler, polyurethane dimethacrylate, and benzoyl peroxide.

7. A multifunctional composite resin disc according to claim 6, characterized in that, The mass ratio of silica filler to polyurethane dimethacrylate is 1.5:2, and the benzoyl peroxide accounts for 1% of the total mass of the prepolymerized filler.

8. A method for preparing a multifunctional composite resin disc, characterized in that, The following steps are described: S1. Raw material preparation: Prepare prepolymerized filler and provide the powdered solid raw materials and liquid raw materials required for each layer, wherein the powdered solid raw materials need to be dried; S2. Batching and mixing: Batching is carried out according to the composition ratio of the upper soft liner, the middle transition layer and the lower hard wear-resistant layer. First, the required powdered solid raw materials for each layer are weighed and mixed to obtain the required powder mixture for each layer. Then, the powder mixture of each layer is mixed and stirred with the liquid raw materials of each layer to obtain the initial materials of each layer. S3. Using a mold with a preset thickness and diameter, the soft liner, transition layer and hard wear-resistant layer are pre-pressed with a pressure of 3 MPa to 7 MPa respectively to make them into blanks with a specific thickness. S4. Freezing the blank material makes the surface of the blank more rigid; S5. Subsequently, the three-layer frozen blanks are stacked in the order of top, middle and bottom, and then cured and molded in one go. During the curing process, the structures between each layer are chemically bonded by methyl methacrylate molecules, thus achieving integration. S6. Finally, heat treatment is performed to further promote curing and eliminate internal stress, ultimately obtaining a multifunctional composite resin disc.

9. The method for preparing a multifunctional composite resin disc according to claim 8, characterized in that, The preparation of the prepolymerized filler includes the following steps: Silica filler was selected and mixed with polyurethane dimethacrylate at a mass ratio of 1.5:2, and a small amount of benzoyl peroxide was added, which accounted for 1% of the total mass. The mixed slurry was stirred and vacuum-treated simultaneously. The pressure was set to 80-95 kPa, the time to 45 minutes, and the mixer speed to 20 r / min. The vacuum-treated slurry was then poured into a stainless steel tray and placed in a curing chamber. The curing chamber temperature is set to 95℃±5℃, and the curing time is 50min, thus forming a cured blank. The blank is then crushed and ground using zirconia spherical abrasives at a speed of 15r / min for 36h. The ground powder is then sieved to ensure that the maximum particle size does not exceed 125μm. Small particle size ensures a finer surface for the product and effectively improves its resistance to staining.

10. The method for preparing a multifunctional composite resin disc according to claim 9, characterized in that, The silica filler is first subjected to silanization treatment, and silica filler with a surface area between 80 and 200 m² / g is mixed with polyurethane dimethacrylate.

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