KR102146627B1 - Fabrication of PFM crown for implant - Google Patents

Abstract

The present invention relates to a method for manufacturing a porcelain fused to metal (PFM) crown implant to remove a process of using scan spray. According to the present invention, the PFM implant comprises a fixture, an abutment, and a crown, wherein the crown comprises a metal frame and a porcelain surface layer. The method comprises the following steps of: stacking a first plastic material on an abutment to form a first wax mold; scanning the outer surface of the first wax mold in three-dimensions to acquire first wax mold scan data; acquiring CAD data for designing the metal frame based on the first wax mold data; processing a second plastic material through CAM based on the CAD data to acquire a second wax mold having the same inner space as the outer surface of the first wax mold; inserting the first wax mold into the second wax mold to prepare an integrated metal frame wax mold; investing and burning out the metal frame wax mold to complete a mold from which the wax molds are removed; inserting metal into the mold to manufacture a metal frame; and using a porcelain material to form a surface layer on the manufactured metal frame.

Description

PFM crown implant manufacturing method {Fabrication of PFM crown for implant}

The present invention relates to a method for manufacturing a PFM crown implant, and in detail, proposes a new manufacturing method with improved stability and improved compatibility with an abutment when manufacturing a metal frame of a PFM crown by 3D scanning and CAD/cam processing. do.

If the tooth is severely damaged, a prosthetic treatment is given to cover the entire tooth, and this treatment is called crown treatment. In terms of material, crown treatment includes zirconia crowns, PFM (Porelain fused to metal crown) crowns, gold crowns, and all-ceramic crowns. As an artificial tooth material that replaces natural teeth, metal has been mainly used in the past, but in recent years, ceramic prostheses capable of expressing a color similar to that of natural teeth have been widely used because of their excellent aesthetics.

The zirconia crown is characterized by high aesthetics as the whole prosthesis is similar to the tooth color, and its strength is very high, so it can withstand the impact of breaking natural teeth. In particular, zirconia is a human-friendly material and has no allergic reaction. The zirconia crown is made by cutting the block material, and the overall tone can be dull, and the process of coloring is also added.

The PFM crown completes the shape of the tooth by constructing a frame with metal and then layering a magnetic material on it. The outer surface has the advantage of being manufactured at a lower cost than a zirconia crown while the tooth color similar to that of natural teeth is expressed by the magnetic quality. On the other hand, there are disadvantages of poor aesthetics, such as low transparency due to exposure of metal to the inside of the oral cavity or low light transmittance, but the aesthetics continues to improve with the recent development of dental technology.

Dental implants are continuously developing as a procedure that replaces teeth by being placed in not only partially damaged teeth, but also areas where teeth are lost as a whole. Types of implants include bridge-type implants and crown-type implants. In the bridge type implant, two or more adjacent artificial teeth are connected to each other to perform an integrally formed prosthesis, and the crown type implant is to perform a single artificial tooth type prosthesis.

As shown in FIG. 1, the implant to be placed in place of the lost tooth is a fixture generally made of titanium, that is, a fixture 10, an abutment 12, and a final restoration. It consists of a crown (14). The fixture is placed in the patient's jawbone (B1) to act as a root, and the crown is exposed over the gum (B2) to form the same or similar shape and color as the missing tooth, and form the appearance of an artificial tooth. Since the abutment fixes the crown to the implant fixture and transmits the load acting on the crown to the implant fixture and jawbone, it is very important in the implant procedure and has a great influence on the subsequent crown design.

With the fixture and abutment completed, the crown is manufactured to suit the individual dental patient. In the case of applying the aforementioned PFM crown, the abutment is scanned to obtain scan data for the metal frame, and based on this data. After making a temporary external solder mold by CAD/CAM processing, after completing the mold based on the solder mold, the metal is finally injected into the mold to complete the metal frame. When manufacturing such a conventional PFM crown, it was difficult to obtain scan data due to the reflectance of the metal abutment, so a 3D scan spray was sprayed on the abutment surface before the scanning process.

The scan spray has an advantage of removing the reflected light of the metal abutment to remove noise from the scan data, but there is a problem that the spray layer must be removed again and the overall process is complicated. In particular, due to the spray layer formed on the surface of the abutment, there is a problem that the suitability of the metal frame and the abutment manufactured based on the scan data is deteriorated, so that the durability or stability of the final implant structure is deteriorated.

Conventionally, a number of technologies related to PFM crowns have been known (patent application 2009-54874, patent application 2017-29766, etc.), but special issues related to scanning of metal abutments or suitability of metal frames and abutments As there was no interest, there was a limit to improving the technology of manufacturing PFM crowns by applying CAD/CAM technology to metal abutments.

The present invention was invented under the above-described technical background, and an object of the present invention is to provide a new PFM crown implant manufacturing method that omits the process of using a scan spray due to the reflectance of a metal abutment when manufacturing an implant structure to which a PFM crown is applied. Is to do.

Another object of the present invention is to propose a new manufacturing process to enable accurate scanning despite the reflectance of a metal abutment when manufacturing a metal frame for a PFM crown.

In addition, other objects and technical features of the present invention will be presented in more detail in the detailed description below.

In order to achieve the above object, the present invention includes a fixture, an abutment, and a crown, wherein the crown is a PFM implant composed of a metal frame and a magnetic surface layer, wherein a first plastic material is stacked on the abutment And 3D scanning the outer surface of the first solder mold to obtain first solder mold scan data, obtain CAD data for designing a metal frame based on the first solder mold scan data, and obtain the CAD data based on the CAD data. 2A plastic material is CAM processed to obtain a second solder mold having the same inner space as the outer surface of the first solder mold, and insert the first solder mold into the second solder mold to prepare an integrated metal frame solder mold. , Investing the lead mold for the metal frame, burnout the lead mold for the metal frame to complete a mold from which the lead mold is removed, and injecting metal into the mold to produce a metal frame, and the manufactured metal frame It provides a PFM crown implant manufacturing method comprising the step of forming a surface layer of a magnetic material on the surface.

In the present invention, it is preferable that the first plastic material of the first lead type is a material having a lower shrinkage rate than that of the second plastic material of the second lead type.

In addition, in the present invention, the method of summoning the lead type for the metal frame is preferably sequentially summoned by stepwise heating and temporary mooring, and the first mooring is performed at 150 to 250° C. for 10 to 30 minutes in the heating process, Secondary mooring at 500 to 700°C for 10 to 30 minutes, and finally summoning at 900°C to produce a stable mold.

According to the present invention, when manufacturing a PFM crown using 3D scan and CAD/cam technology, it is possible to design and manufacture a metal frame even without using a scan spray.

According to the present invention, the suitability of the abutment and the metal frame can be improved, stability and durability of the implant can be increased, and it is possible to provide a PFM implant suitable for individual dental patients.

1 is a cross-sectional view showing a general implant structure
2 is a cross-sectional view showing a state in which a scanning spray layer is formed on the surface of the abutment
3 is a cross-sectional view showing a first solder mold formed on the surface of the abutment
4 is a cross-sectional view showing a second solder mold formed by CAD/CAM processing
5 is a cross-sectional view showing a combined state of the first and second solder molds
6 is a schematic diagram showing the burial process
7 is a cross-sectional view showing a completed metal frame by casting through burial and summoning
8 is a cross-sectional view showing a state in which a completed PFM crown is combined with an abutment

The present invention is a new method for completing a PFM crown by designing a metal frame with improved compatibility with an abutment without using a scan spray when manufacturing a PFM crown using 3D scan and CAD/CAM technology. Suggest.

Specifically, according to the present invention, a temporary solder mold for scanning is formed on the abutment, and a metal frame without spacing equal to the thickness of the spray layer can be manufactured by designing a solder mold for a metal frame based on the temporary solder mold.

In the process of manufacturing an artificial tooth, physical coupling or mechanical accuracy between each element, that is, the fixture and the abutment, the abutment and the crown, is very important to maintain the structural stability of the implant. Various technologies have been developed to improve the compatibility between implant elements. In the case of a zirconia crown, since the zirconia block is precisely processed using a CAD/CAM mechanism, it is relatively free from the compatibility problem.

On the other hand, the PFM crown is made of a frame for a metal frame using dental wax from an oral model made of gypsum for a partially lost tooth, and a metal frame is cast and completed on the basis of this, and then a magnetic material is layered on it and then heat treated to the final product Was completed. For teeth that are completely lost due to the recent advances in implant procedures and the development of related products, there are many procedures in which a fixture and abutment are manufactured in advance and a PFM crown is attached thereon. For this purpose, the surface of the abutment is 3D scanned, and the metal frame is designed using the scanned data. In order to smoothly proceed with the digital scan, the reflectance is lowered by spraying the metal material on the surface of the abutment. As a result, a thin scanning spray layer S is formed on the surface of the abutment 12 as shown in FIG. Is formed. Such a spray layer may not only cause an error in the thickness of the abutment during 3D scanning, but also interfere with uniform scanning of the entire abutment surface. In addition, if a metal frame is manufactured using the scan data obtained in the presence of the spray layer, the compatibility between the finished metal frame and the abutment may be deteriorated, which may deteriorate the durability of the final implant.

The present invention improves the PFM implant manufacturing process, omitting the process of spraying the abutment when designing the metal frame. In addition, instead of directly scanning the abutment surface, there is a technical feature in performing a scan operation for designing a lead type for a metal frame while a temporary solder type is thinly layered on the abutment surface. In addition, a metal frame with improved suitability with an abutment is manufactured by combining a temporary lead type and a metal frame type to perform burial and summoning for metal frame casting. In addition, in the process of burying and summoning the integrated lead type by combining the two materials, it is possible to prevent damage to the investment material and manufacture a mold with physical stability by controlling the summoning process sequentially by stepwise heating and temporary mooring. I can.

Hereinafter, with reference to the drawings, the technical configuration and effects of the present invention will be described in more detail through preferred embodiments.

In order to receive a PFM implant procedure, a patient visits the dentist to establish a treatment plan, and then first obtains an implant prosthetic impression. After taking a prosthetic impression and working on a model with gypsum, a fixture and abutment are manufactured in consideration of the working value and the opposing value. The abutment can be machined off-the-shelf or milled to complete a customized product. When the fixture and abutment are completed, the PFM crown manufacturing process is carried out.

The crown to be joined on the abutment consists of a metal frame and a magnetic layer, and the metal frame is 3D scanned based on the external shape of the abutment, which is an analog model, to obtain scan data, which is digital information, and based on this data, plastic soldering After manufacturing, a mold is obtained using a lead mold. In this process, the present invention forms a first solder mold by laminating a first plastic material on the abutment. The first solder mold 121 is a temporary solder mold for obtaining scan data before forming the second solder mold corresponding to the outer shape of the metal frame, and as shown in FIG. 3, the abutment 12 has a predetermined thickness outside of the abutment 12 It is obtained by layering a plastic material with a small shrinkage.

After that, the scanning operation is performed while the first solder mold is deposited on the abutment surface. That is, the first solder mold scan data is obtained by 3D scanning the outer surface of the first solder mold, and CAD data for designing a metal frame is obtained based on the first solder mold scan data. The first solder type scan data and CAD data are used as digital information for the second solder type manufacturing. Since the first solder mold deposited on the outer surface of the abutment is scanned, not the surface of the abutment, it is not necessary to apply a spray for preventing light scattering on the surface of the metal abutment.

After 3D scanning the outer surface of the first solder mold, a design work (cad work) is performed with the obtained digital information to create a tooth shape and design a metal frame to obtain CAD data. A second solder mold is manufactured by CAM processing a second plastic material based on the CAD data. 4 is a cross-sectional view showing a second solder mold 122 formed by CAD/CAM processing, and the second solder mold is empty as much as the volume of the first solder mold and has the same inner space as the outer surface of the first solder mold. . As the second plastic material, a conventional dental wax used as a lead-type material may be used.

When the second solder mold is completed, the first solder mold is separated from the abutment, and the first solder mold is combined inside the second solder mold. 5 is a cross-sectional view showing a state in which the first solder mold 121 and the second solder mold 122 are combined. The first plastic material of the first lead type is made of a material having a lower shrinkage rate than that of the second plastic material of the second lead type, so that the first lead type can be easily separated from the abutment.

After confirming the suitability by trying the final solder mold combining the first solder mold and the second solder mold on a gypsum model with abutment, the mold work is proceeded for the manufacture of the metal frame. The molding operation goes through the processes of lead-type burial, lead-type summoning, and metal casting, and inserts the first lead-type into the second lead-type to prepare an integrated lead-type for a metal frame, and bury the lead-type for the metal-frame. After placing the casting ring and buffer material around the lead mold with the injection line pin attached to the lead mold, pour the investment material to completely immerse the lead mold. 6 is a schematic diagram showing the burial process, showing a state in which the final solder mold for a metal frame in which the first and second solder molds are combined is buried by the investment material.

When the burial is completed, the lead mold for the metal frame is summoned to complete the mold from which the lead mold is removed, and then the metal is injected into the mold to manufacture the metal frame. Through the process of heating the mold in an electric furnace, the alloy is melted in the crucible of the centrifugal casting machine, and the molten metal fills the empty space of the mold using centrifugal force. When the cast body is cooled, the injection line is cut and polished to finish. 7 is a cross-sectional view showing a metal frame 101 completed by casting through burial and summoning.

In the present invention, since the first lead type and the second lead type used to manufacture the metal frame use different materials, the investment material cracks due to the difference in thermal expansion during the summoning process or the phenomenon that the polymerized resin swells. It can be broken. In order to prevent such a problem, the method of summoning the lead type for the metal frame proceeds with sequential summoning by stepwise heating and temporary mooring. Specifically, after maintaining a thermally stable state by mooring at a low temperature of 150 to 250°C for at least 10 minutes, preferably for 30 minutes or more, the temperature is gradually raised, and the stepwise mooring is performed before the final summoning. Specifically, it is moored at about 500 to 700°C for 10 to 30 minutes, and finally the temperature is raised to 900°C to completely remove the lead type.

The fabricated metal frame is tested on the abutment of the gypsum model, and after confirming the suitability, a surface layer 102 is formed of a magnetic material on the surface of the metal frame 101 to complete the implant PFM crown. 8 is a cross-sectional view showing a state in which the completed PFM crown 110 is coupled to the abutment, and the fixture and the abutment may be subsequently combined with the PFM crown in a state in which the fixture and the abutment are previously placed in the jawbone of the dental patient.

The PFM crown for implants according to the present invention is completed by 3D scanning and CAD/cam processing, and the metal is buried, summoned, and cast in a state in which the first plastic, which is the first solder, is inserted inside the second plastic, which is the second solder. The frame is acquired, and the final metal frame is completed with the combined volume of the first and second solder molds. In the manufacturing process of the metal frame, scan spray is applied. It is possible to obtain a metal frame of a desired shape and volume without using it, so that the suitability of the abutment and the metal frame is improved, the stability and durability of the implant can be increased, and it is possible to provide a PFM implant suitable for individual dental patients. .

In particular, the manufacturing method of the present invention does not significantly change the existing PFM implant manufacturing process and reduces the cost increase factor and solves the problem caused by scanning spray, so it can be easily applied in the dental field, as well as the consumer's need for PFM implants. Reliability can be improved.

Although the present invention has been exemplarily described above through preferred embodiments, the present invention is not limited to such specific embodiments, and the technical idea presented in the present invention, specifically, various forms within the scope described in the claims. It may be modified, changed, or improved with.

10: fixture 12: abutment
101: metal frame 102: magnetic surface layer
110: PFM Crown 121: First soldering type
122: The second delivery sentence

Claims (3)

In a PFM implant comprising a fixture, an abutment, and a crown, the crown comprising a metal frame and a magnetic surface layer,
Laminating a first plastic material on the abutment to form a first solder mold,
3D scan the outer surface of the first solder mold to obtain first solder mold scan data,
Obtain CAD data for designing a metal frame based on the first solder type scan data,
CAM processing a second plastic material based on the CAD data to obtain a second solder mold having the same inner space as the outer surface of the first solder mold,
Inserting the first solder mold into the second solder mold to prepare an integrated metal frame solder mold,
Investing the lead type for the metal frame,
Summoning (burnout) the lead mold for the metal frame to complete the mold from which the lead mold has been removed,
Injecting metal into the mold to manufacture a metal frame,
Comprising the step of forming a surface layer of a magnetic material on the fabricated metal frame surface
PFM crown implant manufacturing method.
The method of claim 1,
The method of manufacturing a PFM crown implant, wherein the first plastic material of the first lead type is a material having a lower shrinkage rate than that of the second plastic material of the second lead type.
The method of claim 1,
The method of summoning the lead type for metal frame is sequentially summoned by stepwise heating and temporary mooring, and the first mooring is performed at 150 to 250°C for 10 to 30 minutes, and the second mooring is performed at 500 to 700°C for 10 to 30 minutes. And, finally, PFM crown implant manufacturing method, characterized in that the final summoned at 900 ℃.

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