JP4430853B2 - Method for manufacturing dental prosthesis - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method for manufacturing a dental prosthesis .
[0002]
[Prior art]
A method for producing a ceramic molded body is a method of pouring mud into a mold and drying it, such as slip casting, and a method of spraying ceramic powder containing a binder onto a mold or the like, such as injection molding. There are pressure molding, plastic molding, etc., but since these are all molded according to the shape of the mold, the appearance is somewhat complicated, but inside the molded body, In a structure that is cut off from the outside, complicated work such as combining and combining partially formed workpieces is required.
The use of other CAD / CAM, to form a virtual three-dimensional structure on the computer, based on this, etc. or by grinding the blocks, a method of forming has been proposed, but leading to the internal structure Cannot escape the complicated work as described above.
[0003]
[Problems to be solved by the present invention]
Many ceramics are used as biomaterials in medical departments and dentistry, and are used as stable and safe materials compared to metals and resins. However, the production of a conventional ceramic molded body is very time-consuming and requires a very complicated operation. In particular, the production of ceramics used as a dental prosthesis is performed manually by a dental technician, and quality and accuracy vary from person to person.
In addition, many ceramic molded bodies are required, not limited to the medical and dental fields.
[0004]
[Means for Solving the Problems]
The present invention is a step of measuring a three-dimensional shape for referring to a certain shape in order to create a target three-dimensional virtual structure. Image analysis step for reference if you need to color. A virtual structure production step in which a three-dimensional virtual structure is created by CAD or the like based on the measurement data described above, and converted into machining data by CAM or the like . A step of producing a molded body while discharging ceramic powder or gel. A method for freely manufacturing a ceramic molded body, which includes a step for firing the molded body, is realized.
Especially this invention respond | corresponds suitably for manufacture of the dental prosthesis which requires various shaping | molding.
Examples of the ceramics in the present invention include hydroxyapatite, calcium phosphate compounds such as α calcium phosphate and β calcium phosphate, various porcelains such as feldspar, quartz and silica, alumina, zirconia, titanium oxide, metal oxides of magnesium oxide, and the like. Is done.
[0005]
The ceramic gel in the present invention is, for example, a mixture of 0.1 to 3 times the amount of water to the above-described ceramic powder (particle size: 0.1 μm to 100 μm) 1, and corn starch as a binder as necessary. , Starch, polyvinyl alcohol and the like are added in an amount of 0.01 to 1 times the ceramic powder. The amount of the binder is appropriately determined depending on the kind of ceramic. In some cases, porcelain powder may be a powder (frit) once melted, solidified and pulverized. Thereby eliminating the impurities by a frit.
Incidentally, the ceramic gel is preferably of the order continue to in dried and solidified shaped work, the speed of drying and solidification is adjustable depending on the shaping rate, also to reduce the injection molding speed as late rate of solidification Such adjustments can be made as appropriate.
Moreover, depending on the case, there is also a method of consolidating the ceramic gel by concentrating the ceramic gel by giving vibration to the built-up one, and lifting the moisture.
[0006]
As a method of forming with ceramic powder, a binder is previously applied to a certain mold, and then ceramic powder is applied. Moreover, when thickness is required, it can be solved by applying a binder and ceramic powder alternately.
In addition, the present invention includes a case where a prosthesis is colored by spraying a colorant instead of a gel.
That is, since the color of the prosthesis manufactured for dentistry is not necessarily the same as the color of the adjacent tooth, the difference in the color of the tooth is particularly noticeable in the front tooth.
Therefore, in order to eliminate this difference, the present invention, for example, after measuring the coloration of adjacent teeth by a CCD camera, a CDS, a light receiving element (for example, a combination of three light receiving elements with RGB filters), a scanner, etc. Based on the coloring data, the colorant is selected and determined electromechanically, and the selected and determined colorant is discharged and colored on the prosthesis so that the prosthesis and the natural tooth cannot be distinguished from each other. It can be formed. In some cases, coloring may also be performed at the time of discharge molding of ceramic gel or ceramic powder.
[0007]
The three-dimensional shape measurement step of the present invention refers to a reference three-dimensional virtual structure that can be used as a reference for a target three-dimensional virtual structure using a contact-type probe or a device capable of measuring a three-dimensional shape such as optical measurement using laser light. Dimensional shape measurement. In addition, this step is not necessarily required if a three-dimensional virtual structure can be produced only by a computer.
If there is something to be used as a reference when coloring ceramic molded bodies, the image analysis step is to take an image into a computer with a digital camera, digital video camera, scanner, etc., and R (red) G (green) which are the three primary colors of light ) A step of analyzing the color of each part by a generally used method such as a method of analyzing the color by separating it into B (blue), and this step is not necessarily required.
The virtual structure fabrication steps, if the shape or color or the like to be a reference is present, incorporating the data into a computer, a shape of interest on a computer, by the CAD or the like, making the virtual structure. Furthermore, this is a step of converting the virtual structure into machining data by CAM or the like.
[0008]
By down loaders, injecting colorant, a ceramics powder or gel syringe. A plurality of syringes are prepared depending on the type of colorant or ceramic. This is a step of producing a ceramic molded body by an apparatus having a three-dimensional drive unit that moves the syringe based on the processing data of the virtual structure and discharges a fixed amount.
The firing step involves firing the ceramic molded body at a temperature of 500 to 2000 ° C. for a time of 0.1 to 48 hours, and is appropriately selected depending on the properties of the ceramic and the molded product. In addition, as an environment for firing, an atmosphere such as vacuum, reduced pressure, high-pressure pressure, nitrogen, argon, or the like is appropriately selected depending on the properties of ceramics, molded products, and the like.
The mold used for discharging ceramic powder or gel is preferably one that has both a role as a work model and a role as a refractory material for porcelain firing, with α-quartz and cristobalite as the basic composition and as a binder. A refractory material using magnesia is conceivable.
In the present invention, the base is, for example, an object to be further modeled, a table on which a model is to be formed, a mold that is to be removed after the model is formed around it.
[0009]
The relative movement in the present invention refers to the case where the base is fixed and the discharge means is moved, and the case where the discharge means is fixed and the base is moved. The discharge operation indicates, for example, discharging ceramic powder or gel continuously or intermittently while moving or in a state where the movement is stopped.
[0010]
Example 1
The ceramic molded body manufacturing apparatus (15) used in the present invention automatically builds a dental ceramic crown. The ceramic body manufacturing apparatus (15) includes an X-axis motor (3), a Y-axis motor (14), and a Z-axis motor (8) on the X axis (12), the Y axis (13), and the Z axis (6), respectively. Therefore, it can be moved three-dimensionally.
Ceramic gel consisting mainly of feldspar and consisting of the following ingredients

Feldspar powder (average particle size 15 μm) 35% by weight
15% by weight of clay
Polyvinyl alcohol 5% by weight
45% by weight of water
Into the ceramic gel tank (1). This ceramic gel is in a state in which colored powder used in dentistry is mixed. Here, six types of ceramics mainly composed of feldspars with different colors were prepared. The six types are A2, A3, A3.5, A4, transparent, and stain in terms of dentistry. Six types of ceramic gels are supplied from each ceramic gel dedicated tank (1) to the syringe (9) through the ceramic transport hose (7) by the ceramic transport pump (2). Each ceramic gel supplied to the syringe (9) is discharged from the discharge port (10) to produce a ceramic molded body (5) . (4) is a stand for mounting the abutment tooth model.
[0011]
The fabrication of a dental prosthesis crown is shown.
The impression of the dentition is taken and an abutment tooth model (16) is made from the impression material. The fire-resistant abutment model material used here is one that is usually used in dentistry, the basic composition is α-quartz and cristobalite, and magnesia is used as the binder. This played both a role as a work model and a role as a refractory material for porcelain firing.
The abutment tooth model (16) obtained by shaping the abutment tooth is digitized by a three-dimensional shape measuring device.
The teeth adjacent to the crown to be prosthetic are photographed with a digital camera, and the color of the image data is analyzed on a personal computer.
Based on the digitized three-dimensional shape data and the analysis data of the color of the adjacent tooth, a virtual crown is produced by CAD. The virtual data on the personal computer is decomposed in the Z-axis direction and converted into machining data.
An abutment tooth model (16) made of a refractory material is mounted at a predetermined position of the ceramic molded body manufacturing apparatus (15 ) (FIG. 2). (11) is a stand mounting jig for mounting the abutment tooth model. (17) is a stand for mounting the abutment tooth model.
A ceramic gel is discharged in a tomographic manner on the refractory abutment tooth model (16) . The ceramic molded body (18) completed as shown in FIG. 3 was fired together with the abutment tooth model (16) in an electric furnace for dental technicians. The fired ceramic molded body (18) was removed from the abutment tooth model (16) and completed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a ceramic molded body manufacturing apparatus for manufacturing a ceramic molded body by discharging a ceramic gel used in an embodiment of the present invention.
FIG. 2 is a diagram illustrating an embodiment of the present invention.
FIG. 3 is a diagram illustrating an embodiment of the present invention.
[Explanation of symbols]
1 Ceramic gel tank
2 Ceramics transport pump
3 X-axis motor
4 Abutment model mounting stand
5 Ceramic molded body
6 Z-axis
7 Ceramics transport hose
8 Z-axis motor
9 Syringe
10 outlet
11 Dedicated mounting jig for mounting the abutment tooth model
12 X axis
13 Y axis
14 Y-axis motor
15 Ceramic molded body manufacturing equipment
16 abutment tooth model
17 Abutment tooth model mounting stand
18 Ceramic compact

Claims (4)

Take an impression of the dentition, make an abutment tooth model from the obtained impression material , form 3D virtual dental prosthesis data from the surface shape data and adjacent tooth data of this abutment tooth model, and fire resistance Manufacture of a dental prosthesis in which the abutment model and the model are fired after injection molding is performed by discharging a ceramic gel on the abutment model having the three-dimensional virtual dental prosthesis data Method. The method for manufacturing a dental prosthesis according to claim 1, wherein color information is added to the adjacent tooth data, and a colorant component of the ceramic gel is adjusted based on the color information.   The method for producing a dental prosthesis according to claim 1, wherein the ceramic gel is obtained by adding 0.1 to 3 times the amount of water and binder to 0.01 to 1 times the amount of the ceramic powder 1. The method of manufacturing a dental prosthesis according to claim 2, wherein the color of the prosthesis is determined based on an image obtained by photographing the color of the adjacent tooth with a digital camera, a digital video camera, or a CCD camera .

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