WO2023191144A1

WO2023191144A1 - Method for manufacturing separable ceramic dental implant

Info

Publication number: WO2023191144A1
Application number: PCT/KR2022/004623
Authority: WO
Inventors: 박정식
Original assignee: (주)메세텍
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2023-10-05
Also published as: KR20230142039A

Abstract

The present invention relates to a method for manufacturing a separable ceramic dental implant and, more specifically, to a method for manufacturing a separable ceramic dental implant, the method comprising: injection molding a ceramic dental implant by using a screw core pin and a polymer insert made of a polymer material and including a screw-shaped groove part having a shape corresponding to the screw shape of the dental implant; and then separating the screw core pin and the polymer insert and performing a solvent degreasing step, a heat degreasing step, and a sintering step, thereby manufacturing a ceramic dental implant without a parting line formed thereon.

Description

Manufacturing method of detachable dental implant made of ceramic material

The present invention relates to a method of manufacturing a detachable dental implant made of ceramic material, and more specifically, to the production of a detachable dental implant made of ceramic material that does not form a parting line, thereby increasing the production efficiency of the product. It's about method.

As the economy and standard of living improve, aesthetic demands increase, and the development of implant products using zirconia (ZrO2), a ceramic material instead of metal (titanium), is expanding in the field of dental prosthetics. Dental implant products using zirconia are being produced in Europe and the United States. The demand is rapidly increasing, especially in developed countries.

In Europe, etc., the general manufacturing method for ceramic zirconia implants is to manufacture zirconia rod materials by milling (diamond grinding), which is very difficult to manufacture, expensive, and difficult to mass-produce, and has limitations in terms of mechanical properties and manufacturing shape. has.

Recently, attempts have been made to apply ceramic powder injection molding technology to manufacture ceramic implants, but the general ceramic powder injection molding method inevitably generates a parting line in the mold structure in order to realize the implant screw portion.

If a ceramic implant is inserted into the gum bone using the sintered body for dental prosthetics in the presence of a parting line, there is a high possibility that gum damage will occur due to the parting line, so it is not recommended to use it. It is a very difficult situation.

Accordingly, the parting line part must be subjected to a secondary machining process (grinding, milling, etc.) after sintering to manufacture the ceramic implant. This secondary machining method makes the ceramic screw machining process difficult and time-consuming. Because it took a long time, it had the problems of high manufacturing costs and difficulties in mass production.

(Patent Document 1) Korean Patent Publication No. 10-2017-011302 (2017.10.12), Method of manufacturing screw parts by insert ceramic powder injection molding

(Patent Document 2) Korean Patent, No. 10-1137013 (2012.04.09), Manufacturing method of dental zirconia implant member by injection molding and dental zirconia implant member using the same

The present invention was created to solve this problem, and the purpose of the present invention is to provide a method of manufacturing a detachable dental implant made of ceramic that can produce a detachable dental ceramic implant without forming a parting line. It is for this purpose.

The objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the description below.

In order to achieve the above object, the present invention uses a first screw core pin with a first thread corresponding to the screw shape of a dental implant as an insert core, and injects a first feedstock made of polymer to form a cylindrical bottom. A polymer insert manufacturing step of injection molding the polymer insert that is opened and has a thread-shaped groove portion having a shape corresponding to the first thread portion; A first screw core pin separation step of rotating and disengaging the first screw core pin coupled to the polymer insert; The second threaded portion of the second screw core pin is placed inside the threaded groove of the polymer insert, and the second feedstock made of ceramic material is injected, so that a cylindrical fastening portion corresponding to the first threaded portion is formed on the outer surface. An implant injection molding step of injection molding an implant injection body having an open lower end and a fastening groove having a shape corresponding to the second screw portion. A second screw core pin separation step of rotating and disengaging the second screw core pin coupled to the implant injection body; A polymer insert removal step of dissolving the polymer insert coupled to the implant injection molding body using an organic solvent; A solvent degreasing step to remove paraffin wax and stearic acid present in the implant extruded body; A heating degreasing step of removing polyethylene by heating the implant extruded body from which paraffin wax and stearic acid have been removed; A sintering step of sintering the degreased body obtained through the heating degreasing step. A method of manufacturing a detachable dental implant made of ceramic material is provided, comprising:

In a preferred embodiment, the first feedstock is made of polymethyl methacrylate (PMMA) or styrene-acrylonitrile (SAN), and has a melting point of 160°C or higher.

In a preferred embodiment, the second feedstock is zichronium oxide (ZrO2) powder, ATZ (Alumina Toughened Zirconia) powder, or a ceramic powder in which 1 to 20 wt% of zichronium oxide (ZrO2) powder and alumina (Al2O3) powder are mixed. , a mixture of polyethylene, paraffin wax, and stearic acid is used.

In a preferred embodiment, the polymer insert removal step uses acetone, methyl ethyl ketone (MEK), hexane, heptane, THF, benzene, ether, or chloroform as an organic solvent.

In a preferred embodiment, the polymer insert removal step removes the polymer insert by immersing the implant injection molded body with the polymer insert in the organic solvent for 12 hours.

In a preferred embodiment, the solvent degreasing step uses THF (Tetra Hydro Furan) as a solvent and is performed within 72 hours at a temperature of 20°C to 30°C.

In a preferred embodiment, the heat degreasing step includes a first heat degreasing step of raising the temperature to 250 to 230° C. at a rate of 0.1 to 0.4° C./min and maintaining the temperature for 4 to 8 hours; A second heating degreasing step in which the temperature is raised to 170-350°C at a rate of 0.2-0.5°C/min and maintained for 4-8 hours; A third heating degreasing step of raising the temperature to 350-500°C at a rate of 0.2-0.4°C/min and maintaining it for 4-8 hours; And a pre-sintering step of raising the temperature to 500-850°C at a rate of 1.0-5.0°C/min and maintaining it for 2 hours.

In a preferred embodiment, the sintering step includes a first sintering step of raising the temperature to 250-600°C at a rate of 1.0-2.0°C/min and maintaining it for 1-2 hours; A second sintering step of raising the temperature to 600-1,100°C at a rate of 0.7-1.5°C/min and maintaining it for 2 hours; And a third sintering step of raising the temperature to 1,100-1,450°C at a rate of 0.5-1.0°C/min and maintaining it for 2-4 hours.

The present invention has the following excellent effects.

According to the method of manufacturing a detachable dental implant made of ceramic material of the present invention, a dental implant made of ceramic material is used using a polymer insert and a screw core pin formed of a polymer material with a thread-shaped groove having a shape corresponding to the screw shape of the dental implant. After injection molding the implant, the screw core pin and polymer insert are separated, and a separate parting dental implant made of ceramic material without a parting line is manufactured through a solvent degreasing step, a heat degreasing step, and a sintering step. There is no need for post-treatment processes such as line removal processes, which has the effect of increasing product production efficiency.

Furthermore, it can be very easily used to manufacture implants with various thread shapes, and has the advantage of manufacturing implant parts not only of ceramic materials but also of metal (titanium, Co-Cr-Mo materials, etc.), and of complex-shaped thread parts. Since it is a technology that can be applied to industrial products, it can be usefully used in various fields such as information and communications, automobiles, semiconductors, medicine, precision machinery, and aerospace.

1 is a step diagram illustrating a method of manufacturing a detachable dental implant made of ceramic material according to the present invention.

Figure 2 is a diagram for explaining the polymer insert manufacturing steps of the present invention.

Figure 3 is a diagram for explaining the implant injection molding step of the present invention.

Figure 4 is a photograph showing various types of polymer inserts manufactured through the polymer insert manufacturing step of the present invention.

Figure 5 is a photograph showing a dental implant (implant injection body) manufactured by the method of manufacturing a detachable dental implant made of ceramic material according to the present invention.

100: Dental implant injection body

100a: fastening part

100b: Fastening groove

110: polymer insert

110a: Threaded groove part

P1: 1st screw core pin

P2: 2nd screw core pin

The terms used in the present invention are general terms that are currently widely used as much as possible. However, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning described or used in the detailed description of the invention rather than the simple name of the term is considered. Therefore, its meaning must be understood.

Hereinafter, the technical configuration of the present invention will be described in detail with reference to preferred embodiments shown in the attached drawings.

However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Like reference numerals refer to like elements throughout the specification.

1 is a step diagram illustrating a method of manufacturing a detachable dental implant made of ceramic material according to an embodiment of the present invention.

Referring to FIG. 1, the method for manufacturing a detachable dental implant made of ceramic material according to an embodiment of the present invention is a process for manufacturing a detachable dental implant made of ceramic material in which a parting line is not formed by injection molding. As shown in Figure 2, first, a polymer insert manufacturing step (S100) of manufacturing a polymer insert 110 made of a polymer material is performed.

The polymer insert manufacturing step (S100) is a process for injection molding a polymer insert 110 in a cylindrical shape with an open bottom and a thread-shaped groove 110a formed, and includes a first thread portion corresponding to the screw shape of a dental implant ( The first threaded core pin (P1) formed with a) is used as an insert core, and a first feedstock made of polymer is injected to form a threaded groove portion (110a) having a shape corresponding to the first threaded portion (a). Polymer inserts are injection molded.

Here, the first feedstock may be made of PMMA (polymethyl methacrylate) or SAN (styrene-acrylonitrile) material.

In addition, the first feedstock may be made of a material having a melting point of at least 160°C, and it is more preferable to use a polymer having a melting point of 200°C or more.

Afterwards, a first screw core pin separation step (S200) of rotating and disengaging the first screw core pin (P1) coupled to the polymer insert 110 is performed.

That is, after the injection molding of the polymer insert 110 is completed by the mold in which the first screw core pin (P1) is used as an insert, the first screw core pin (P1) is rotated away, leaving no parting line. The thread-shaped groove portion 110a may be formed.

Next, as shown in FIG. 3, the manufactured polymer insert 110 is used as an insert in a mold for ceramic injection molding, and the second screw core pin (P2) is used as an insert core to inject a ceramic implant. The implant injection molding step (S300) of injection molding the body is performed.

To be more specific, the second threaded portion (b) of the second screw core pin (P2) is located inside the threaded groove portion (110a) of the polymer insert (110), and a second feedstock made of ceramic material is installed. By injection, as shown in FIG. 5, a fastening part 100a of a shape corresponding to the first screw part (a) is formed on the outer surface in a cylindrical shape, and the lower end is opened to connect the second screw part (b). The implant injection body 100 with the fastening groove 100b of a corresponding shape is formed by injection molding.

Additionally, the second feedstock is a mixture of ceramic powder, polyethylene, paraffin wax, and stearic acid.

Here, the ceramic powder may be ZrO2 (3YSZ) powder, ATZ (Alumina Toughened Zirconia) powder, or a powder in which 1 to 20 wt% of alumina (AL2O3) powder is mixed with ZrO2 (3YSZ) powder.

Next, a second screw core pin separation step (S400) of rotating and disengaging the second screw core pin (P2) coupled to the implant injection body 100 is performed.

That is, since the first screw core pin (P2) is rotated away, the fastening groove (100b) without a parting line can be formed in the implant injection body (100).

Next, a polymer insert removal step (S500) is performed in which the polymer insert 110 formed in the implant injection molded body 100 is dissolved using an organic solvent.

The organic solvent used in the polymer insert removal step (S500) may be acetone, MEK, hexane, heptane, THF, benzene, ether, or chloroform.

At this time, it is preferable to immerse the implant injection body 100 on which the polymer insert 110 is formed in the organic solvent for 12 hours to remove the polymer insert 110.

Next, a solvent degreasing step (S600) is performed to remove paraffin wax and stearic acid present in the implant extruded body 100.

The solvent used in the solvent degreasing step (S600) may be THF (Tetra Hydro Furan), and is preferably treated within 72 hours at a temperature of 20°C to 30°C.

Next, a heating degreasing step (S700) is performed to remove polyethylene by heating the implant extruded body from which paraffin wax and stearic acid have been removed.

The heat degreasing step (S700) may be performed sequentially through a first heat degreasing step, a second heat degreasing step, a third heat degreasing step, and a pre-sintering step.

More specifically, the first heating degreasing step is to raise the temperature to 250-230 ℃ at a rate of 0.1-0.4 ℃/min and then maintain it for 4-8 hours, and to 170-350 ℃ at a rate of 0.2-0.5 ℃/min. A second heating degreasing step in which the temperature is raised and maintained for 4 to 8 hours, a third heating degreasing step in which the temperature is raised to 350 to 500 ℃ at a rate of 0.2 to 0.4 ℃/min and maintained for 4 to 8 hours, and 1.0 to 5.0 ℃ The heating degreasing step is completed by sequentially going through a pre-sintering step in which the temperature is raised to 500-850°C at a rate of /min and maintained for 2 hours.

Thereafter, a sintering step (S800) of sintering the degreased body obtained through the heating degreasing step (S700) is performed.

The sintering step (S800) can be completed through a three-step sintering process. To be described in more detail, the first temperature is raised to 250-600°C at a rate of 1.0-2.0°C/min and then maintained for 1-2 hours. Sintering step, the second sintering step in which the temperature is raised to 600-1,100 ℃ at a rate of 0.7-1.5 ℃/min and maintained for 2 hours, and the temperature is raised to 1,100-1,450 ℃ at a rate of 0.5-1.0 ℃/min and then 2-4 It is completed sequentially through the third sintering step, which is maintained for a period of time.

Example

Polymer insert manufacturing and first screw core pin separation steps (S100, S200)

Using SAN material as a raw material, a polymer insert 110 with a thread-shaped groove 110a of a shape corresponding to the thread shape of the implant was manufactured by injection molding so that the thread shape of the dental implant could be transferred. Figure 4 shows photographs of polymer inserts manufactured in various shapes.

At this time, a first screw core pin with a first threaded portion was used as an insert of the mold used for injection molding, and by rotating and removing the first screw core pin from the injection molded body, the screw core pin was attached to the polymer insert 110. A groove portion 110a was formed.

Implant injection molding step and first screw core pin separation step (S300, S400)

The polymer insert 110 was used as an insert in a mold for ceramic injection molding, a second screw core pin with a second threaded portion was used as an insert core, and a mixture of ZrO2, PE, paraffin wax, and stearic acid was used as a feedstock. , an implant injection body was molded in a cylindrical shape, with a fastening part having a shape corresponding to the first threaded part formed on the outer surface, and the lower end being opened to form a fastening groove having a shape corresponding to the second screwed part.

Afterwards, the second screw core pin coupled to the implant injection body was rotated away and separated.

Polymer insert removal step (S500)

With the polymer insert formed on the implant extruded body, it was immersed in acetone solvent and reacted at a temperature of 25°C for 12 hours to remove the polymer insert.

Solvent degreasing step (S600)

Afterwards, it was reacted in THF solvent at a temperature of 25°C for 48 hours to remove paraffin wax and stearic acid present in the implant extruded body.

Heating degreasing step (S700)

The implant extruded body from which paraffin wax and stearic acid were removed was heated at room temperature to 800°C for 2 hours to remove polyethylene.

Sintering step (S800)

Thereafter, the obtained degreased body was sintered at a temperature of 1,450°C for 2 hours to produce a separate (2-body type) ceramic implant. A photograph of the sintered dental implant sintered body is shown in FIG. 5.

As described above, according to the method of manufacturing a detachable dental implant made of ceramic material according to the present invention, a polymer insert made of a polymer material and a screw core pin with a thread-shaped groove having a shape corresponding to the screw shape of the dental implant is formed. After injection molding a dental implant made of ceramic material, the screw core pin and polymer insert are separated, and through the solvent degreasing step, heat degreasing step, and sintering step, a detachable dental implant made of ceramic material that does not form a parting line is made. By manufacturing, there is no need for post-processing processes such as a separate parting line removal process, which has the effect of increasing the production efficiency of the product.

As discussed above, the present invention has been illustrated and described with reference to preferred embodiments, but it is not limited to the above-described embodiments and is intended to be used by those skilled in the art without departing from the spirit of the invention. Various changes and modifications will be possible.

Implants manufactured using the manufacturing method of the present invention can be provided as dental implants made of metal (titanium, Co-Cr-Mo materials, etc.) as well as ceramic materials. Furthermore, the manufacturing method of the present invention allows for threads of complex shapes to be formed. Since it is a technology that can be applied to existing industrial products, it can be usefully used in various fields such as information and communications, automobiles, semiconductors, medicine, precision machinery, and aerospace.

Claims

A first screw core pin with a first thread portion corresponding to the screw shape of a dental implant is used as an insert core, and a first feedstock made of polymer is injected to form a cylindrical shape with the bottom open and corresponding to the first thread portion. A polymer insert manufacturing step of injection molding a polymer insert having a thread-shaped groove portion formed therein;

A first screw core pin separation step of rotating and disengaging the first screw core pin coupled to the polymer insert;

The second threaded portion of the second screw core pin is placed inside the threaded groove of the polymer insert, and the second feedstock made of ceramic material is injected, so that a cylindrical fastening portion corresponding to the first threaded portion is formed on the outer surface. An implant injection molding step of injection molding an implant injection body having an open lower end and a fastening groove having a shape corresponding to the second screw portion.

A second screw core pin separation step of rotating and disengaging the second screw core pin coupled to the implant injection body;

A polymer insert removal step of dissolving the polymer insert coupled to the implant injection molding body using an organic solvent;

A solvent degreasing step to remove paraffin wax and stearic acid present in the implant extruded body;

A heating degreasing step of removing polyethylene by heating the implant extruded body from which paraffin wax and stearic acid have been removed;

A method of manufacturing a detachable dental implant made of ceramic, comprising a sintering step of sintering the degreased body obtained through the heating degreasing step.
According to clause 1,

The first feedstock is

A method of manufacturing a detachable dental implant made of ceramic material, wherein polymethyl methacrylate (PMMA) or styrene-acrylonitrile (SAN) material is used and the melting point is above 160°C.
According to clause 1,

The second feedstock is

Zirconium oxide (ZrO2) powder, ATZ (Alumina Toughened Zirconia) powder, or ceramic powder containing 1 to 20 wt% of zichronium oxide (ZrO2) powder and alumina (Al2O3) powder, and a mixture of polyethylene, paraffin wax, and stearic acid. A method of manufacturing a detachable dental implant made of ceramic material, characterized in that it is used.
According to clause 1,

The polymer insert removal step is a method of manufacturing a detachable dental implant made of ceramic material, characterized in that acetone, methyl ethyl ketone (MEK), hexane, heptane, THF, benzene, ether, or chloroform is used as an organic solvent.
According to clause 4,

The polymer insert removal step is

A method of manufacturing a detachable dental implant made of ceramic, characterized in that the implant injection body on which the polymer insert is formed is immersed in the organic solvent for 12 hours to remove the polymer insert.
According to clause 1,

The solvent degreasing step is

A method of manufacturing a detachable dental implant made of ceramic material, wherein THF (Tetra Hydro Furan) is used as a solvent and processed within 72 hours at a temperature of 20°C to 30°C.
According to clause 1,

The heating degreasing step is

A first heating degreasing step in which the temperature is raised to 250-230°C at a rate of 0.1-0.4°C/min and maintained for 4-8 hours;

A second heating degreasing step in which the temperature is raised to 170-350°C at a rate of 0.2-0.5°C/min and maintained for 4-8 hours;

A third heating degreasing step of raising the temperature to 350-500°C at a rate of 0.2-0.4°C/min and maintaining it for 4-8 hours; and

A method of manufacturing a detachable dental implant made of ceramic material, comprising a pre-sintering step of raising the temperature to 500-850 °C at a rate of 1.0-5.0 °C/min and maintaining it for 2 hours.
According to clause 1,

The sintering step is

A first sintering step in which the temperature is raised to 250-600°C at a rate of 1.0-2.0°C/min and maintained for 1-2 hours;

A second sintering step of raising the temperature to 600-1,100°C at a rate of 0.7-1.5°C/min and maintaining it for 2 hours; and

A method of manufacturing a detachable dental implant made of ceramic material, comprising: a third sintering step of raising the temperature to 1,100 to 1,450 °C at a rate of 0.5 to 1.0 °C/min and maintaining it for 2 to 4 hours.