KR101717255B1 - Recycled zirconia block and method for preparing the same - Google Patents

Abstract

The present invention relates to a recycled zirconia block and a production method thereof. More specifically, the present invention relates to a recycled zirconia block exhibiting excellent physical properties and exterior quality compared to existing zirconia blocks, by filling holes of waste zirconia blocks with plaster or zirconia powder filler. The present invention further relates to a production method thereof.

Description

Recycled zirconia block and method for preparing same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerated zirconia block and a method of manufacturing the same, and more particularly, to a regenerated zirconia block produced by recycling a waste zirconia block generated in a scouring process, and a manufacturing method thereof.

The zirconia block is a round plate-shaped artificial tooth generally used for producing an artificial tooth including an implant, a tooth bridge, and a tooth crown.

Generally, after purchasing a zirconia block, the zirconia block is cut out using a CAD according to the shape and size of the artificial tooth sent from the dentist, and the zirconia block is cut in consideration of the plastic shrinkage ratio of the zirconia in the subsequent firing. Cutting process.

Fig. 1 is a photograph of a general zirconia block, and Fig. 2 is a photograph of a waste zirconia block after the zirconia block is precisely cut.

Referring to FIG. 2, the waste zirconia block after the precise cutting of the zirconia block is left with a plurality of holes and a body portion that can still be cut into artificial teeth.

Up to now, there has been used a method of simply disposing such a waste zirconia block, or filling the voids of the waste zirconia block by a gypsum reaction after filling the waste zirconia block with gypsum, and recycling the zirconia block.

However, since the coefficient of expansion of the gypsum is high, the zirconia block is pushed out between the voids of the block after drying, so that cracks are formed partially, or gypsum adheres to the zirconia after CAD processing. Gypsum reacts to form a poor layer formed. Such a defective layer is a zirconia-gypsum composite layer, for example, and causes defective artificial teeth.

Therefore, the development of a regenerated zirconia block capable of preventing generation of a defective layer by cracking due to a gypsum reaction or reaction between zirconia and gypsum in a regenerated zirconia block using gypsum, and the development of a regenerated zirconia block using a substance other than gypsum Development is required.

Korean Patent No. 1533530

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a regenerated zirconia block using gypsum or zirconia powder as a filler and a method of manufacturing the same.

It is another object of the present invention to provide an artificial tooth made of reclaimed zirconia block in various embodiments of the present invention and a method of manufacturing the artificial tooth.

An aspect of the present invention is a zirconia block comprising a plurality of holes;

A gypsum powder or zirconia powder filler filled in the hole; And

And a buffer layer formed between the hole and the gypsum powder filler.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a buffer layer on a surface of a plurality of holes included in a waste zirconia block;

Filling the inside of the hole formed with the buffer layer by filling gypsum powder; And

And curing the waste zirconia block filled with the gypsum powder.

According to another aspect of the present invention, there is provided a method of manufacturing a zirconia block, comprising: charging a mixture of zirconia powder and a binder by filling a plurality of holes included in a waste zirconia block; And

And firing a waste zirconia block filled with a mixture of the zirconia powder and the binder.

Another aspect of the present invention is to provide an artificial tooth made of the reclaimed zirconia block.

According to still another aspect of the present invention, there is provided a method for manufacturing a reclaimed zirconia block, comprising the steps of: And a step of baking.

According to the present invention, it is possible to recycle a waste zirconia block, which is generally discarded after being used in a tooth or dental clinic, so that it is possible to reduce the cost of manufacturing a new zirconia block with expensive zirconia and increase the use efficiency of the zirconia block .

Further, since the regenerated zirconia block according to the present invention exhibits physical properties equal to or higher than that of the novel zirconia block, it can be widely manufactured as various types of artificial teeth.

Particularly, the body part can be recycled into an artificial tooth in a waste zirconia block including a plurality of holes and a body part excluding the holes.

Figure 1 is a photograph of a typical zirconia block.
2 is a photograph of a waste zirconia block after forming an artificial tooth.
3 is a schematic view of a regenerated zirconia block including gypsum according to an embodiment of the present invention.
4 is a schematic view of a zirconia block including zirconia powder according to another embodiment of the present invention.
5 is a flowchart illustrating a process of manufacturing a regenerated zirconia block including gypsum according to an embodiment of the present invention.
FIG. 6 is a flowchart illustrating a manufacturing process of a regenerated zirconia block including zirconia powder according to another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

An aspect of the present invention relates to a waste zirconia block comprising a plurality of holes; A gypsum powder or zirconia powder filler filled in the hole; And a buffer layer formed between the hole and the gypsum powder filler.

In the waste zirconia block including the plurality of holes, the hole refers to a void space remaining after cutting an artificial tooth in the zirconia block.

FIG. 3 is a schematic view of a regenerated zirconia block filled with a gypsum powder filler according to an embodiment of the present invention, which is a photograph before firing.

Referring to FIG. 3, the regenerated zirconia block includes a closed zirconia block including a plurality of holes; A gypsum powder filler filled in the hole; And a buffer layer formed on the surface of the hole.

The gypsum powder filler may be used in a kneaded state in which gypsum powder and water are mixed. In consideration of mechanical properties of the molded and formed zirconia block, 5 to 12 parts by weight of water may be mixed with 100 parts by weight of gypsum powder .

In addition, the gypsum powder filler may be mixed with calcium phosphate. Since the calcium phosphate has the same properties as cement, it can improve the mechanical strength of the filler part with the gypsum powder filler, and can harden and solidify the connection part of the gypsum powder filler and the buffer layer without any unevenness. , 20 to 100 parts by weight of calcium phosphate may be included relative to 100 parts by weight of the gypsum powder filler.

The gypsum powder may be a dental gypsum powder, and the dental gypsum powder may be general gypsum, gypsum and hard gypsum depending on the strength. Among them, the hardened gypsum is the strongest. Specifically, the hardened gypsum can harden even when the water is least diluted, and the hardened gypsum can be hardened and hardened because the water is diluted less.

The buffer layer can prevent the compression impact applied to the waste zirconia block while the gypsum is dried during the manufacturing process and can prevent the formation of the zirconia-gypsum composite layer which can be generated by directly pushing the waste zirconia block . Since the zirconia-gypsum composite layer has a zirconia-gypsum reaction layer formed during sintering at 1300 to 1600 캜 during the production of the artificial teeth, it causes defective artificial teeth. Therefore, the buffer layer prevents the formation of the zirconia- Thereby making it possible to reduce the defective rate of artificial teeth.

The buffer layer may be formed by coating a composite of soft plastic resin and calcium phosphate on the surface of the hole.

The flexible plastic resin is an elastic resin capable of absorbing the impact applied to the waste zirconia block due to expansion of gypsum, and is preferably at least one selected from silicon, polyethylene, polypropylene, polyvinyl chloride and polystyrene.

The calcium phosphate has the same properties as cement and can harden and solidify at the connection portion between the gypsum powder filler and the waste zirconia block so that the gypsum powder filler and the waste zirconia block can be connected without any sense of difference.

The soft plastic resin and the calcium phosphate can be mixed at a content ratio of 10 to 50% by weight and 50 to 90% by weight in consideration of minimization of impact applied to the zirconia block by gypsum expansion and unity of gypsum and waste zirconia blocks .

In addition, the buffer layer minimizes the impact applied to the zirconia block by the expansion of the gypsum and considers the unity of the gypsum and the waste zirconia block. And 3 to 7 mm in thickness on the hole surface of the waste zirconia block.

4 is a schematic view of a regenerated zirconia block filled with zirconia powder according to another embodiment of the present invention, which is a photograph before firing.

Referring to FIG. 4, the regenerated zirconia block includes a waste zirconia block including a plurality of holes; And a zirconia powder filler filled in the hole, wherein the zirconia powder filler is filled in the hole while being mixed with the binder.

The binder may be an aqueous binder which is removed by burning by firing during the manufacture of an artificial tooth.

The water-soluble binder may be selected from the group consisting of polyvinyl alcohol (PVA), an acrylic resin, a latex resin, a vinyl acetate resin, a vinyl acetate resin, an acryl-styrene copolymer resin, ethylene vinyl acetate (EVA), a water-soluble polyurethane resin, , Urea resin, rosin resin, melamine resin, starch, cellak, gelatin and casein.

The mixing ratio of the zirconia powder filler and the binder may be 10 to 50% by weight and 50 to 90% by weight, in consideration of the moldability and the mechanical properties of the reclaimed zirconia block to be produced.

The zirconia powder may be a Yttria-stabilized zirconia (YSZ) powder, a pulverized zirconia block, or a zirconia powder.

By using the powder of the zirconia block as the zirconia powder, recyclability can be improved.

The zirconia powder filler may further include calcium phosphate. Since the calcium phosphate has the same properties as cement and hardens and solidifies, the calcium phosphate can improve the mechanical strength of the filler portion with the zirconia powder filler, and the zirconia powder filler and the waste zirconia block can be connected without any sense of difference. , 20 to 100 parts by weight of calcium phosphate may be included relative to 100 parts by weight of the zirconia powder filler.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a buffer layer on a surface of a plurality of holes included in a waste zirconia block; Filling the inside of the hole formed with the buffer layer by filling gypsum powder; And curing the waste zirconia block filled with the gypsum powder.

5 is a flowchart illustrating a process of manufacturing a regenerated zirconia block including gypsum according to an embodiment of the present invention.

Referring to FIG. 5, a buffer layer is formed on a plurality of hole surfaces formed in a waste zirconia block, and filled with a gypsum powder filler to fill the zirconia block, thereby producing a regenerated zirconia block.

The buffer layer may be formed by coating a composite of a soft plastic resin and calcium phosphate on the surface of the plurality of holes. Specific examples of the function and constituent materials of the buffer layer are as described above.

The gypsum powder filler may be filled in the holes by mixing and kneading gypsum and water. The dilution ratio between the gypsum and water may be 5 to 12 parts by weight based on 100 parts by weight of the gypsum, considering the mechanical properties of the molded zirconia block.

The gypsum powder filler is filled and then cured for 6 to 12 hours to prepare a regenerated zirconia block.

Another aspect of the present invention is a method for manufacturing a zirconium-containing zirconia block, comprising filling a zirconia powder and a binder mixture in a plurality of holes contained in a waste zirconia block to fill the zirconia block; And firing a waste zirconia block filled with a mixture of the zirconia powder and the binder.

FIG. 6 is a flowchart illustrating a manufacturing process of a regenerated zirconia block including zirconia powder according to another embodiment of the present invention.

Referring to FIG. 6, a regenerated zirconia block can be prepared by mixing a zirconia powder and a binder, and filling the voids of the waste zirconia block.

Specific examples of the zirconia powder and the binder and mixing ratios are as described above.

After charging the zirconia powder filler, the zirconia block is fired at 1100 to 1200 ° C for 1 to 3 hours to prepare a regenerated zirconia block.

Yet another aspect of the present invention relates to an artificial tooth prepared by using the regenerated zirconia block, wherein the artificial tooth may be at least one selected from the group consisting of an implant, a tooth crown, and a tooth bridge.

According to another aspect of the present invention, there is provided a method of manufacturing a reclaimed zirconia block, And a method of manufacturing an artificial tooth including the step of baking.

The firing may be performed at 1300 to 1600 ° C. By baking at the above temperature, a zirconia block having an appearance similar to a natural tooth and having enhanced strength can be produced.

And further comprising the step of applying the glaze after the baking step, the aesthetic similarity with the natural teeth can be further improved.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope and content of the present invention can not be construed to be limited or limited by the following Examples. In addition, it is apparent that, based on the teachings of the present invention including the following examples, those skilled in the art can easily carry out the present invention in which experimental results are not specifically shown.

Example 1 Preparation of Reclaimed Zirconia Block and Artificial Tooth Using Gypsum

1-1. Manufacture of recycled zirconia blocks using gypsum

In order to form a buffer layer on the hole surface of the waste zirconia block including a plurality of holes, 50 wt% of silicone resin and 50 wt% of calcium phosphate were mixed as soft plastic resin, and then coated on the hole surface to form a buffer layer .

Thereafter, 8 parts by weight of water was mixed with 100 parts by weight of dental gypsum powder as a gypsum powder, filled in the holes of the waste zirconia block coated with the buffer layer, and cured to prepare a regenerated zirconia block.

1-2. Manufacture of artificial teeth

The regenerated zirconia block prepared in 1-1 above was processed into artificial teeth using CAD / CAM and then cut to produce artificial teeth.

Example 2 Preparation of Reclaimed Zirconia Block and Artificial Tooth Using Zirconia Powder

2-1. Manufacture of reclaimed zirconia block using zirconia powder

A yttria-stabilized zirconia powder obtained by pulverizing a waste zirconia block was prepared.

70% by weight of the yttria-stabilized zirconia powder and 30% by weight of PVA as a binder were mixed, filled in the pores of the waste zirconia block, and then sintered at 1100 ° C for 2 hours to prepare a reclaimed zirconia block.

2-2. Manufacture of artificial teeth

The regenerated zirconia block prepared in the above 2-1 was cut into artificial teeth using CAD / CAM and cut to produce artificial teeth.

Comparative Example 1

A regenerated zirconia block was prepared in the same manner as in Example 1 except that no buffer layer was formed.

Comparative Example 2

A regenerated zirconia block was prepared in the same manner as in Example 2 except that no binder was used.

Comparative Example 3

A commercial zirconia block (Kubotec, Korea) was prepared.

Experimental Example 1: Comparison of appearance of recycled zirconia block

In the regenerated zirconia block prepared in each of Examples 1 and 2 and Comparative Examples 1 and 2, the overall appearance of the block was observed around the boundary between the recycled zirconia block and the filler, for example, gypsum and zirconia powder.

As a result, it was observed that in the waste reclaimed zirconia of Examples 1 and 2, space was formed on the surface of the filler and the hole, and no boundary was formed, thereby making the block having a smooth surface as a whole.

On the other hand, in the waste reclaimed zirconia of Comparative Examples 1 and 2, voids were formed due to shrinkage of the filler in some holes, and in some holes, portions reacted at the interface between the gypsum and zirconia were found to be defective.

Experimental Example 2: Flexural strength and hardness test

The flexural strength and hardness of the regenerated zirconia block prepared in Examples 1 and 2 and Comparative Examples 1 and 2 and the conventional zirconia block of Comparative Example 3 were measured and the results are shown in Table 1. At this time, the bending strength was measured by three-point bending strength, and the hardness was measured by Vicker's hardness.

Bending strength
(MPa) Hardness
(Hv) Example 1 1100 1450 Example 2 1140 1300 Comparative Example 1 950 1050 Comparative Example 2 1000 1000 Comparative Example 3 1140 1400

As a result, it was confirmed that the pulmonary regenerated zirconia blocks of Examples 1 and 2 exhibited flexural strength and hardness equal to or higher than that of the conventional zirconia block of Comparative Example 3. [

Experimental Example 3: Observation of recycled zirconia block according to buffer layer thickness

The appearance of the reclaimed zirconia block prepared by forming the buffer layers 1 mm, 3 mm, 5 mm, 7 mm, 9 mm and 11 mm, respectively, in the same manner as in Example 1, for example, (i) And (ii) cracks that can be generated by expanding as the gypsum powder filler is cured and impacting the pneumatic zirconia block, which is formed at the boundary between the filler material and the waste zirconia block, thereby forming a zirconia- the formation of cracks was visually observed.

The bending strength and the hardness were measured. The bending strength was measured at a three-point bending strength, and the hardness was measured by Vicker's hardness. The results are shown in Table 2.

Buffer layer thickness
(mm) Whether zirconia-gypsum composite layer is formed crack
Formation Bending strength
(MPa) Hardness
(Hv) Sample 1 One ○ ○ 1000 1200 Sample 2 3 X X 1100 1420 Sample 3 5 X X 1100 1450 Sample 4 7 X X 1070 1430 Sample 5 9 X X 990 1150 Sample 6 11 X X 960 1080

As a result, as shown in Table 2, when the thickness of the buffer layer is 1 mm, the zirconia of the gypsum powder filler and the zirconia block of the waste zirconia block react directly to form a zirconia-gypsum composite layer, , And a crack is formed.

In the case of the buffer layer thickness of 9 mm and 11 mm, cracks were not formed in the zirconia-gypsum composite layer, but the bending strength and hardness were decreased as the buffer layer with elasticity became thicker.

As a result, when a gypsum powder filler is filled in a hole in a waste zirconia block to form a buffer layer having a thickness of 3 to 7 mm in manufacturing a regenerated zirconia block, the defective rate of the regenerated zirconia block is lowered and mechanical properties such as bending strength and hardness Can be secured.

Experimental Example 4: Comparison of strength and hardness according to the type of gypsum powder

The bending strength and the hardness were measured after preparing a regenerated zirconia block by varying the type of gypsum powder. The bending strength was measured by three-point bending strength, and the hardness was measured by Vickers hardness (Vicker's hardness), and the results are shown in Table 3.

Gypsum powder Bending strength
(MPa) Hardness
(Hv) Sample 1 Dental porcelain 1100 1450 Sample 2 General plaster for dentistry 1050 1420 Sample 3 Dental gypsum plaster 1190 1500 Sample 4 Plaster for art 940 1250

As a result, as shown in Table 3, bending strength and hardness were both excellent when dental pavers, general plaster and hard plaster were used as gypsum powders. In particular, when using dental hard gypsum, bending strength and hardness You can see the best.

On the other hand, bending strength and hardness were significantly decreased when using artistic gypsum.

As described above, the regenerated zirconia block according to the present invention exhibits physical properties and appearance equal to or higher than that of conventional zirconia blocks. In the conventionally discarded waste zirconia block, a body portion excluding a plurality of holes is recycled, The possibility of manufacturing a tooth can be confirmed.

It will be apparent to those skilled in the art that the present invention is not limited to the embodiments described above and that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the appended claims. As shown in FIG.

It will be understood by those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention as defined by the appended claims and their equivalents. .

Claims (26)

A waste zirconia block comprising a plurality of holes;
A gypsum powder or zirconia powder filler filled in the hole; And
And a buffer layer formed between the hole and the gypsum powder filler. The method according to claim 1,
Wherein the buffer layer comprises a composite of a soft plastic resin and calcium phosphate coated on the surface of the hole. 3. The method of claim 2,
Wherein the soft plastic resin is at least one selected from the group consisting of silicon, polyethylene, polypropylene polyvinyl chloride and polystyrene. 3. The method of claim 2,
Wherein the soft plastic resin and the calcium phosphate composite comprise 10 to 50 wt% of soft plastic resin and 50 to 90 wt% of calcium phosphate. The method according to claim 1,
Wherein the buffer layer has a thickness of 3 to 7 mm. The method according to claim 1,
Wherein the zirconia powder filler comprises zirconia powder and a binder. 8. The method of claim 7,
Wherein the zirconia powder filler comprises 10 to 50 wt% zirconia powder and 50 to 90 wt% binder. The method according to claim 6,
The binder may be at least one selected from the group consisting of polyvinyl alcohol (PVA), acrylic resin, latex resin, vinyl acetate resin, vinyl acetate resin, acryl-styrene copolymer resin, ethylene vinyl acetate (EVA), water-soluble polyurethane resin, polyvinyl acetate Wherein the water-soluble binder is at least one selected from the group consisting of urea resin, urea resin, rosin resin, melamine resin, starch, cellar, gelatin and casein. The method according to claim 1,
Wherein the zirconia powder is a powder of a waste zirconia block. 10. The method of claim 9,
Wherein the zirconia powder is a Yttria-stabilized zirconia (YSZ) powder. The method according to claim 1,
Wherein the gypsum powder filler or the zirconia powder filler further comprises calcium phosphate. Forming a buffer layer on the surface of the plurality of holes included in the waste zirconia block;
Filling the inside of the hole formed with the buffer layer by filling gypsum powder; And
And curing the waste zirconia block filled with the gypsum powder. 13. The method of claim 12,
Wherein the gypsum powder is mixed with water to form a kneaded state. 13. The method of claim 12,
Wherein the gypsum powder is mixed with calcium phosphate to fill the regenerated zirconia block. 13. The method of claim 12,
Wherein the buffer layer is formed by mixing a soft plastic resin and calcium phosphate and coating the surface of the hole with the soft plastic resin and calcium phosphate. 16. The method of claim 15,
Wherein the soft plastic resin is at least one selected from the group consisting of silicon, polyethylene, polypropylene, and polyvinyl chloride and polystyrene. Filling a plurality of holes included in the waste zirconia block by filling a mixture of zirconia powder and a binder into the holes; And
And firing a waste zirconia block filled with the mixture of the zirconia powder and the binder. 18. The method of claim 17,
Wherein the zirconia powder is a powder of a waste zirconia block. 18. The method of claim 17,
Wherein the zirconia powder is Yttria-stabilized zirconia (YSZ) powder. 18. The method of claim 17,
The binder may be at least one selected from the group consisting of polyvinyl alcohol (PVA), acrylic resin, latex resin, vinyl acetate resin, vinyl acetate resin, acryl-styrene copolymer resin, ethylene vinyl acetate (EVA), water-soluble polyurethane resin, polyvinyl acetate Wherein the water-soluble binder is at least one water-soluble binder selected from urea resin, urea resin, rosin resin, melamine resin, starch, cellak, gelatin and casein. 13. The method of claim 12,
Wherein the zirconia powder is mixed with calcium phosphate to fill the regenerated zirconia block. An artificial tooth prepared with the reclaimed zirconia block of any one of claims 1 to 11. 23. The method of claim 22,
Wherein the artificial tooth is at least one selected from the group consisting of an implant, a tooth crown, and a tooth bridge. 20. A method for manufacturing a reclaimed zirconia block, comprising the steps of: forming an artificial tooth form on a reclaimed zirconia block produced by the manufacturing method of any one of claims 12 to 21; And
And baking the mixture. 25. The method of claim 24,
Wherein the baking step is performed at a temperature of 1300 to 1600 캜. 25. The method of claim 24,
Further comprising the step of applying a glaze after the firing step.

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