Method for manufacturing ceramic tooth by three-dimensional lamination
阅读说明：本技术 三维积层制造陶瓷牙齿的方法 (Method for manufacturing ceramic tooth by three-dimensional lamination ) 是由 颜丰明 严竣荣 陈立恒 于 2018-07-13 设计创作，主要内容包括：一种三维积层制造陶瓷牙齿的方法,包括；步骤(Sa)准备多个投影切层图像及浆料,其中投影切层图像通过将牙齿的立体图像沿特定方向以特定厚度切层而成；浆料由材料粉末、光固化树脂、溶剂及添加剂调配而成；步骤(Sb)将浆料均匀铺设在基板上形成牺牲层；步骤(Sc)将浆料均匀铺设于牺牲层上形成反应层；步骤(Sd)根据多个投影切层图像中的一者投射照射光源至反应层,而反应层中的浆料受到照射光源的照射后固化成型；步骤(Se)重复前述步骤(Sc)及(Sd),形成瓷牙坯体；步骤(Sf)使用水或有机溶剂冲洗瓷牙坯体；及步骤(Sg)高温烧结瓷牙坯体,形成陶瓷牙齿。(A method of three-dimensional additive manufacturing of a ceramic tooth, comprising; preparing a plurality of projected sliced layer images and slurry, wherein the projected sliced layer images are formed by slicing a stereoscopic image of a tooth in a specific direction at a specific thickness; the slurry is prepared by mixing material powder, light-cured resin, solvent and additive; uniformly paving the slurry on a substrate to form a sacrificial layer; step (Sc) evenly paving the slurry on the sacrificial layer to form a reaction layer; step (Sd) of projecting an irradiation light source to the reaction layer according to one of the plurality of projected slice images, and curing and molding the slurry in the reaction layer after the slurry is irradiated by the irradiation light source; step (Se) repeating the steps (Sc) and (Sd) to form a porcelain tooth blank; step (Sf) washing the porcelain tooth blank by using water or an organic solvent; and (Sg) sintering the ceramic tooth blank at a high temperature to form the ceramic tooth.)
1. A method of three-dimensional additive manufacturing of ceramic teeth, comprising:
(Sa) preparing a plurality of projected sliced images, which are formed by slicing a stereoscopic image of a tooth in a specific direction at a specific thickness, and a slurry; the slurry is prepared by mixing material powder, light-cured resin, solvent and additive; the material powder comprises at least one of alumina powder, zirconia powder and glass ceramic powder, the light-cured resin comprises at least one of water-soluble resin and water-dispersible resin, the solvent is water or a mixed solvent containing water and alcohol, and the additive comprises at least one of a dispersant, a binder and a plasticizer;
(Sb) uniformly spreading the slurry on a substrate to form a sacrificial layer;
(Sc) uniformly spreading the slurry on the sacrificial layer to form a reaction layer;
(Sd) projecting an irradiation light source to the reaction layer according to one of the plurality of projection slice images, the slurry in the reaction layer being cured and molded after being irradiated by the irradiation light source, wherein the irradiation light source is visible light or ultraviolet light and is disposed above the substrate;
(Se) repeating the step (Sc) and the step (Sd) to form a porcelain tooth blank;
(Sf) rinsing the porcelain tooth blank with water or an organic solvent; and
(Sg) sintering the ceramic tooth blank at a high temperature to form the ceramic tooth.
2. The method for three-dimensional laminated manufacturing of ceramic teeth according to claim 1, wherein if the solvent is water, the solvent accounts for 10% by weight or more of the material; if the solvent is a mixed solvent, water accounts for 50 wt% or more of the mixed solvent.
3. The method of claim 1, wherein the material powder is 53 to 83 parts by weight, the dispersant is 0.5 to 3.5 parts by weight, the plasticizer is 0.5 to 5 parts by weight, the binder is 2 to 7 parts by weight, the photocurable resin is 7 to 20 parts by weight, and the solvent is 10 to 28 parts by weight.
4. The method of claim 1, wherein the alcohol comprises at least one of ethanol, isopropanol, propylene glycol, and hexylene glycol.
5. The method of claim 1, wherein the dispersant comprises at least one of a polycarboxylate, a polymeric ammonium salt, and a polymeric sodium salt; the plasticizer includes at least one of polyethylene glycol having a molecular weight of 150 or more and 450 or less and glycerin.
6. The method of claim 1, wherein the adhesive comprises at least one of polyethylene glycol having a molecular weight of 1500 or more and 8000 or less, polyvinyl alcohol, and polyethylene oxide.
7. The method of claim 1, wherein each projected slice image comprises a slice pattern and at least one slurry recovery pattern of a perspective view of the tooth; forming the porcelain tooth blank formed by the layer cutting pattern and a slurry recycling body formed by the slurry recycling pattern in the step (Se); recovering the recovered slurry in the step (Sf).
8. The method for manufacturing a ceramic tooth according to claim 1, wherein the substrate is made of a material or a structure having a water absorption of 5% or more.
9. The method for three-dimensional laminated manufacturing of ceramic teeth according to claim 1, wherein in the step (Sf), the temperature of the water or the organic solvent is 25 to 50 ℃.
10. The method of claim 1, wherein the slurry has a viscosity of less than 1000 cp.
Technical Field
The invention relates to a method for manufacturing a ceramic tooth, in particular to a method for manufacturing a ceramic tooth by three-dimensional lamination.
Background
The conventional methods for manufacturing ceramic teeth mainly include conventional manual grinding process and automatic process using machine tool manufacturing technology.
However, in the conventional manual grinding process, the finished product is determined by the manual skill of the dental technician in making the wax mold and casting the dental crown, so the quality of the ceramic tooth is not uniform, and the process steps include complicated adjustment procedures such as oral cavity mold removal, manual grinding and shaping, and subsequent assembly adjustment, so the production cycle time of each ceramic tooth process is quite long.
On the other hand, although the technology of manufacturing dentures by machine tools, commonly known as CNC manufacturing, has good production efficiency, can effectively replace manual work, and can reduce the influence of process level differences among dental technicians, the production cost is high due to expensive raw materials and the machining and design cost of CNC manufacturing, and only a single denture can be produced by a single machine tool at a time. Furthermore, CNC manufacturing techniques are limited to machining tools, and grinding sculptures for specific angles and shapes are subject to considerable limitations and obstacles, and thus often do not provide the ceramic teeth desired by the patient to be manufactured closely and precisely.
Therefore, there is a need to develop a method for manufacturing ceramic teeth in three-dimensional lamination, which can greatly reduce the process time and can also be customized to provide the ceramic teeth that the patient needs to replace.
Disclosure of Invention
The main objective of the present invention is to provide a method for three-dimensional laminated ceramic teeth, which can provide ceramic teeth with automatic molding according to the customization requirement, and maintain the high stability of the manufacturing quality of the ceramic teeth. In addition, the shaping slurry used in the manufacturing process of the method disclosed by the invention not only can greatly avoid the peculiar smell and the volatilization of toxic substances in the environment, but also provides the environmental protection effect of a recovery mechanism.
To achieve the above object, the present invention provides a method for manufacturing a ceramic tooth by three-dimensional lamination, comprising the steps of: step Sa preparing a plurality of projected sliced images, which are obtained by slicing a stereoscopic image of a tooth in a specific direction at a specific thickness, and a slurry; the slurry is prepared by mixing material powder, light-cured resin, solvent and additive; the material powder comprises at least one of alumina powder, zirconia powder and glass ceramic powder, the light-cured resin comprises at least one of water-soluble resin and water-dispersible resin, the solvent is water or a mixed solvent containing water and alcohol, and the additive comprises at least one of a dispersant, a binder and a plasticizer; step Sb, uniformly paving the slurry on a substrate to form a sacrificial layer; step Sc, uniformly paving the slurry on the sacrificial layer to form a reaction layer; step Sd, projecting an irradiation light source to the reaction layer according to one of the plurality of projection cut layer images, curing and molding the slurry in the reaction layer after being irradiated by the irradiation light source, wherein the irradiation light source is visible light or ultraviolet light and is arranged above the substrate; step Se, repeating the step Sc and the step Sd to form a porcelain tooth blank; step Sf washing the porcelain tooth blank by using water or an organic solvent; and step Sg, sintering the ceramic tooth blank at a high temperature to form the ceramic tooth.
Accordingly, the present invention manufactures a ceramic tooth by using a three-dimensional lamination manufacturing technique, so that any shape of tooth can be formed without limitation, including a crown, an implant having various structures, and a porcelain tooth in which the crown and the implant are integrally formed, and the implant having various structures includes a cone-shaped implant, an implant having a shape imitating a natural tooth root, an implant having a base (abutment), and the like. In addition, the support frame for traditional 3D printing is replaced by the sacrificial layer, and the support frame does not need to be additionally machined, removed and cleaned after molding. On the other hand, the invention adopts water-based materials, is environment-friendly, safe and nontoxic, and is convenient to wash.
Secondly, the present invention provides a method for three-dimensional laminate manufacturing of ceramic teeth, wherein, if the solvent is water, the solvent accounts for more than 10% by weight of the material; if the solvent is a mixed solvent, water accounts for 50 wt% or more of the mixed solvent. Therefore, the material adopted in the invention belongs to an aqueous system, the manufacturing process is safe and non-toxic, the cleaning is convenient, and the slurry can be recycled.
Furthermore, the present invention provides a method for manufacturing a ceramic tooth by three-dimensional lamination, wherein the material powder is 53 to 83 parts by weight, the dispersant is 0.5 to 3.5 parts by weight, the plasticizer is 0.5 to 5 parts by weight, the binder is 2 to 7 parts by weight, the photocurable resin is 7 to 20 parts by weight, and the solvent is 10 to 28 parts by weight. In addition, the invention provides a method for manufacturing ceramic teeth by three-dimensional lamination, wherein the alcohol comprises at least one of ethanol, isopropanol, propylene glycol and hexylene glycol.
Further, the present invention provides a method for three-dimensional laminated manufacturing of a ceramic tooth, wherein the dispersant comprises at least one of a polycarboxylate, a polymer ammonium salt and a polymer sodium salt; the plasticizer includes at least one of polyethylene glycol having a molecular weight of 150 or more and 450 or less and glycerin. In addition, the invention provides a method for manufacturing ceramic teeth by three-dimensional lamination, wherein the adhesive comprises at least one of polyethylene glycol with the molecular weight of more than 1500 and less than 8000, polyvinyl alcohol and polyethylene oxide.
Furthermore, the invention provides a method for manufacturing ceramic teeth by three-dimensional lamination, wherein each projection cutting image comprises a cutting layer graph and at least one slurry recycling graph of a stereogram of the teeth; forming a porcelain tooth blank body formed by a layer cutting pattern and a slurry recycling body formed by a slurry recycling pattern in the step Se; the slurry recycling body is recycled in the step Sf. In other words, the pulp recovery body after illumination curing is convenient for recycling the pulp and can not cause environmental pollution.
Preferably, the present invention provides a method for manufacturing a ceramic tooth by three-dimensional build-up, wherein the substrate is made of a material or a structure having a water absorption of 5% or more. Therefore, the substrate can absorb water or other solvents for the sacrificial layer and the reaction layer, and the reaction layer can be immediately cured by irradiation without waiting for the time of water volatilization, so that the process efficiency can be remarkably improved.
More preferably, the present invention provides a method for manufacturing a ceramic tooth by three-dimensional lamination, wherein in the step Sf, the temperature of the water or the organic solvent is 25 to 50 ℃, thereby increasing the speed of washing the ceramic tooth blank. In addition, the invention provides a method for manufacturing ceramic teeth by three-dimensional lamination, wherein the viscosity of the slurry is less than 1000cp, less residual bubbles are generated due to low viscosity of the slurry, the bubbles are easy to remove, the whole manufacturing efficiency is improved, the sacrificial layer and the reaction layer are convenient to uniformly lay, and the thickness of the reaction layer is favorably controlled.
Drawings
FIG. 1 is a flow chart illustrating a method for manufacturing a ceramic tooth by three-dimensional lamination according to an embodiment of the present invention.
Fig. 2 is a schematic diagram illustrating a principle of stereoscopic image slicing and light curing according to an embodiment of the present invention.
Fig. 3A is a schematic diagram illustrating the spreading of a slurry to form a sacrificial layer according to an embodiment of the present invention.
Fig. 3B is a schematic diagram illustrating the application of slurry to form a reaction layer according to an embodiment of the present invention.
FIG. 4A is a schematic diagram illustrating an irradiation light source projecting onto a reaction layer according to an embodiment of the invention.
Fig. 4B is a schematic diagram illustrating a molded porcelain tooth blank in a sacrificial layer according to an embodiment of the present invention.
Fig. 5 is a schematic view illustrating simultaneous molding of a plurality of porcelain tooth blanks according to another embodiment of the present invention.
Fig. 6 is a schematic view illustrating a ceramic tooth blank and a paste recovery body formed on a reaction layer according to still another embodiment of the present invention.
Detailed Description
Before describing the method of three-dimensional laminated ceramic teeth in detail in this embodiment, it is noted that similar components will be denoted by the same component reference numerals in the following description. Moreover, the drawings of the present disclosure are for illustrative purposes only and are not necessarily to scale, nor are all details presented in the figures.
Referring to fig. 1 and fig. 2, fig. 1 is a flowchart illustrating a method for manufacturing a ceramic tooth by three-dimensional lamination according to an embodiment of the present invention, and fig. 2 is a schematic diagram illustrating a stereoscopic image lamination and light curing according to an embodiment of the present invention. As shown in the figure, a plurality of projected slice images I and a paste are prepared in step Sa.
As shown in fig. 2, each projection slice image I is a cross-sectional image formed by horizontally and transversely cutting a stereo image I _3d of a specific tooth to be shaped by a specific thickness layer by layer. Furthermore, after the image data of the teeth formed in the oral cavity of the patient is scanned by the optical scanning system, the image data of the specific teeth is subjected to drawing, repairing or redesigning to obtain a perfect tooth shape, so as to obtain three-dimensional image data I _3d, and then the image processing unit is used for performing corresponding layer-by-layer transverse cutting according to the thickness t of the reaction layer of the subsequent process to obtain a plurality of projection cut layer images I _ P _1 to I _ P _ n, so that the three-dimensional image data can be sequentially used in the step-by-layer projection curing process of the subsequent plastic ceramic teeth.
In addition, it is to be noted that, after the irradiation light source shown in fig. 2 is projected to the slurry by projecting the slice image I _ P, the irradiation light is cured to form the ceramic blank layer. However, this is only for illustrating the principle of the present invention, and as for the prior art, the light spot of the contour to be formed can be directly emitted by the optical machine PR without the need of the solid projection mask ML, and the detailed technology is described later.
On the other hand, a slurry for molding is prepared by blending material powder, a photocurable resin, a solvent and an additive. Wherein the material powder may be at least one of alumina powder, zirconia powder, glass ceramic powder, and the light-curable resin includes at least one of a water-soluble resin and a water-dispersible resin. In the present embodiment, the photocurable resin mainly comprises 30-55 wt% of acrylate monomer, 30-40 wt% of acrylate oligomer, 1-4 wt% of photoinitiator, and 0-2 wt% of additive, wherein the additive is not absolutely necessary and may be optionally added according to actual conditions.
Second, the solvent may be one hundred percent water or an alcohol solvent, such as comprising water and at least one of Ethanol (ET), Isopropanol (IPA), Propylene Glycol (PG), and Hexylene Glycol (HG), wherein the water is preferably deionized water. For example, in terms of overall slurry weight percent, in a preferred embodiment of the present invention, if the solvent is one hundred percent water, the solvent comprises more than 10 weight percent of the overall material; in contrast, if the solvent is a mixed solvent, such as an alcohol solvent, the solvent still accounts for more than 10% by weight of the entire material, while water accounts for more than 50% by weight of the mixed solvent.
However, in the present embodiment, a mixed solvent of water and ethanol is selected, wherein ethanol is mainly used as a resin solubilizer to reduce the porosity; according to practical experiments, when ethanol is not used as a resin solubilizer formula, the prepared ceramic body has high porosity of about 2 to 10 percent, but if ethanol is used as the resin solubilizer formula, the porosity can be greatly reduced to below 2 percent. Furthermore, ethanol is used in a minimum amount and has good solvency compared to other resin solubilizers, and is relatively safe if the slurry is contacted with the skin. In addition, the surface tension of water can be effectively reduced by using a small amount of ethanol, and cracking of a blank or coating defects such as shrinkage cavity or depression can be reduced when nano powder materials are stacked.
Further, the additive includes at least one of a dispersant, a binder, and a plasticizer. More specifically, the dispersant comprises at least one of a polycarboxylate, a polymeric ammonium salt (e.g., ammonium polyacrylate), and a polymeric sodium salt (e.g., sodium polyacrylate); the dispersing agent has the main functions of accelerating the deagglomeration speed of material powder and shortening the dispersing time; and secondly, the time for re-agglomeration of the particles of the material powder is delayed, and the particles are kept in a dispersed state for a long time.
In addition, the plasticizer comprises at least one of polyethylene glycol (such as PEG #200 and PEG #400) with a molecular weight of 150 to 450, and glycerin (glycerol), and is mainly used for lowering the glass transition temperature of the adhesive, so that the adhesive has better flexibility at normal temperature. In addition, the adhesive contains at least one of polyethylene glycol (e.g., PEG #2000, PEG #4000, PEG #6000), polyvinyl alcohol, and polyethylene oxide with a molecular weight of 1500 or more and 8000 or less, provides strength to the ceramic body after drying, resists a shearing force during blade coating, and adjusts viscosity to prevent particle sedimentation.
Still further, in a preferred embodiment of the present invention, the material powder is 53 to 83 parts by weight, the dispersant is 0.5 to 3.5 parts by weight, the plasticizer is 0.5 to 5 parts by weight, the binder is 2 to 7 parts by weight, the photocurable resin is 7 to 20 parts by weight, and the solvent is 10 to 28 parts by weight with respect to the weight percentage of the entire paste. Therefore, the viscosity of the slurry is less than 1000cps and the slurry has better fluidity by the composition proportion of the components. Moreover, the low viscosity of the slurry will produce less residual bubbles and easily remove the bubbles, resulting in improved overall manufacturing efficiency.
Next, please refer to fig. 3A, which is a schematic diagram of paving slurry according to an embodiment of the present invention. In step Sb in the flowchart shown in fig. 1, the slurry is uniformly laid on the
On the other hand, the supply unit 2 of the present embodiment is further connected to a storage tank (not shown), and a fluid control valve (not shown) is provided between the storage tank and the supply unit 2, and controls the amount of slurry supplied from the storage tank to the supply unit 2 each time, which is exactly the amount of slurry supplied to the
In the present embodiment, since the
Please refer to fig. 3B, which is a schematic diagram of forming the
In other words, in the present embodiment, by using the solvent based on deionized water and the
Fig. 4A is a schematic view illustrating an irradiation light source projecting onto a reaction layer according to an embodiment of the invention. In step Sd of the flowchart shown in fig. 1, the irradiation
Next, after the curing
Then, after the ceramic blank is completely formed, step Sf is performed, in this embodiment, warm water or an organic solvent with a temperature of 25 to 50 ℃ slightly higher than room temperature is used to easily dissolve away the slurry in the
Moreover, the water-based light-cured resin adopted in the embodiment also absorbs water to expand by about 5% -15%, and the uncured material is spread during expansion, so that the structure of the material is loose, and the cleaning and the obtaining of the porcelain tooth blank 133 are facilitated. The slurry dissolved away by water or organic solvent can be recycled and reused as the slurry for subsequent molding, thereby effectively reducing the overall manufacturing cost.
In addition, please refer to fig. 5, which is a schematic diagram illustrating a plurality of porcelain tooth blanks formed at the same time according to another embodiment of the present invention. As shown in the figure, the present embodiment is characterized in that a plurality of ceramic tooth blanks are simultaneously manufactured in one process, as long as a plurality of three-dimensional images of teeth to be shaped are configured in the same projection slice image, the irradiation light source can simultaneously emit a plurality of light spots, and a plurality of curing regions 131a and 131b are simultaneously generated on the
Fig. 6 is a schematic view illustrating a ceramic tooth blank and a slurry recycling body formed on a reaction layer according to still another embodiment of the invention. In this embodiment, the projected sliced layer image includes a plurality of slurry recycling patterns in addition to the tooth stereogram sliced layer pattern, so that when the irradiation
And finally, performing sintering and ceramization step Sg, namely performing high-temperature sintering on the
In summary, the present invention has at least the following advantages:
the three-dimensional lamination technology is used to prepare the ceramic tooth, so the outline and the shape of the ceramic tooth are not limited, and rather fine shapes or surface grains can be prepared.
The sacrificial layer replaces the support member, and the ceramic tooth is directly formed without an additional support member, thereby eliminating the process of removing the support member and grinding the protrusion caused by the support member.
The ceramic blank is formed by utilizing the illumination projection layer cutting image, so that a plurality of ceramic teeth with different shapes can be simultaneously finished in one process.
The sacrificial layer and the slurry recycling body can be recycled and reused as slurry, so that the environment is protected, and the material cost can be reduced.
Through the water absorption characteristic of the substrate, the step procedure of irradiation, curing and molding of the irradiation light source can be carried out after the slurry is layered, and the forming time of the porcelain tooth blank body is greatly shortened.
The invention adopts the water-based material, namely, the water is used as the whole solvent or the main solvent, and the water-soluble light-cured resin is used, so the invention is safe, non-toxic and convenient to clean.
The above-described embodiments are merely exemplary for convenience in explanation, and the scope of the present invention is not limited to the above-described embodiments, but should be defined by the appended claims.
Description of the symbols
11 substrate
12 sacrificial layer
13 reaction layer
131. 131a, 131b curing zone
1311 ceramic tooth blank solidifying zone
1312 slurry recovery body curing zone
132 uncured zone
133 ceramic body
2 supply unit
21 stock chest
22 linear type discharge port
23 scraping board
I _ P projection slice image
I _ P _1 projection slice image
I _ P _ n projection slice image
I _3d stereoscopic image
PR optical machine
ML entity projection shading
thickness of t reaction layer
Sa to Sg.
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