KR102381025B1 - Manufacturing method of dental prosthesis using 3D printer - Google Patents

Abstract

The present invention relates to a method for manufacturing a dental prosthesis, and the dental prosthesis manufactured according to the present invention has improved bonding strength and overall resistance strength between the core and porcelain, and has a color and light transmittance similar to natural teeth, thereby improving aesthetics. .
In addition, the manufacturing method according to the present invention has the effect of easily manufacturing a dental prosthesis in a short time.

Description

Manufacturing method of dental prosthesis using 3D printer

The present invention relates to a method of manufacturing a dental prosthesis, and more particularly, to a method of easily manufacturing a dental prosthesis having improved bonding strength and overall resistance strength between a core and a ceramic material using a 3D printer.

An artificial replacement of a tooth or dental tissue is called a dental prosthesis. Dental prostheses include removable dentures and non-removable crowns and bridges.

Polymers, metals, alloys, ceramics, and composite materials are used as materials for dental prostheses. In general, noble metal materials such as gold, non-noble metal alloy materials such as nickel-chromium alloys or cobalt-chromium alloys, and ceramic materials are widely used. .

Recently, users' expectations for aesthetics are increasing due to the improvement of living standards, and in the case of dental prostheses that cover the entire tooth, such as crowns, the demand for dental prostheses using ceramic materials is higher than that of conventional metal prostheses.

As such a ceramic material, the use of dental prostheses using zirconia is increasing in consideration of mechanical performance such as strength and durability, but zirconia has limitations in aesthetics due to its turbid surface color.

Accordingly, a dental prosthesis manufactured by veneering a porcelain layer on a zirconia core in the form of a coating is more preferred than manufacturing a dental prosthesis using a zirconia-only material.

However, in the case of a prosthesis in which a porcelain such as resin or ceramic is coated on the surface of zirconia, there is a problem in that the adhered resin or ceramic is peeled off or the zirconia core itself is fractured.

In this regard, Korean Patent No. 10-1763573 discloses a technique for increasing the mechanical bonding force between resins or ceramics by etching the zirconia ceramic surface with an etchant composition containing hydrofluoric acid, sulfuric acid, a catalyst and methyl alcohol to increase the roughness. Although this has been disclosed, there is a disadvantage in that a separate etching composition preparation step and an etching step are required.

In addition, there are products containing silicon dioxide to increase the bonding strength and transmittance of zirconia, but this also has a problem in that the strength is significantly lowered.

In addition, in the case of zirconia blocks, there are disadvantages in that the price of the block and the price of the processing tool are high, expensive equipment is required, and a long manufacturing time is required.

Republic of Korea Patent Publication No. 10-1763573

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a method of easily manufacturing a dental prosthesis having improved bonding strength and overall resistance strength between a core and a ceramic material using a 3D printer.

In order to achieve the above object, the present invention

laminating and curing the photocurable restorative composition to form a core;

sintering the core; and

It provides a method of manufacturing a dental prosthesis comprising the step of applying a glass composition to the surface of the sintered core and heat-treating the glass composition to penetrate the inside of the core.

The dental prosthesis manufactured according to the present invention has improved bonding strength and overall resistance strength between the core and porcelain, and has a color and light transmittance similar to natural teeth, thereby improving aesthetics.

In addition, the manufacturing method according to the present invention has the effect of being able to easily manufacture a dental prosthesis in a short time.

1 is a pyrolysis graph of the photocurable repair composition of Preparation Example 1 of the present invention.
2 is a graph confirming the flexural strength of the dental prosthesis manufactured according to Example 1 of the present invention.

Hereinafter, the present invention will be described in detail. The terms or words used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

The present invention is

laminating and curing the photocurable restorative composition to form a core;

sintering the core; and

It provides a method of manufacturing a dental prosthesis comprising the step of applying a glass composition to the surface of the sintered core and heat-treating the glass composition to penetrate the inside of the core.

The photocurable repair composition refers to a repair composition including a material cured by light irradiation, and may include a photocurable monomer, a photocurable oligomer, a photocurable polymer, a photoinitiator, a diluent, a catalyst, and the like.

The core is a part that fills the space in contact with the tooth to be restored, supports the remaining tooth structure, strengthens the holding power of the prosthesis, and serves to provide an insulating effect to the dental nerve area.

The shape of the core may be designed based on the scan of the tooth model.

As an example, the core may be designed by scanning a tooth model manufactured by directly taking impressions of natural teeth with an extraoral scanner, and then designing and correcting it using a computer aided design (CAD) program.

Alternatively, after scanning a dental model manufactured using an intraoral scanner with an extraoral scanner, it may be designed and designed by using a computer aided design (CAD) program.

The core is formed by laminating and curing a photocurable restorative composition based on the designed design.

The curing may be made by irradiating ultraviolet (UV), visible light, laser, etc., and preferably by irradiating ultraviolet (UV).

In this case, the forming of the core may be characterized in that the photocurable repair composition is laminated with a 3D printer and cured to proceed.

When using a 3D printer, the photocurable repair composition is preferably in the form of a slurry. Accordingly, the photocurable restorative composition may be prepared as a slurry of an appropriate viscosity by supplying moisture using distilled water if necessary, and then injected into a slurry tube of a 3D printer and sprayed.

The 3D printer may use a DLP (Digital Light Processing), SLA ([Stereolithography Apparatus), or SLS (Selective Laser Sintering) method, preferably a Poly-Jet method combining FDM (Fused Deposition Modeling) and DLP. can be used

The DLP method is a method of making a molded body by irradiating ultraviolet light to a liquid photocurable polymer in a water tank with a beam projector. It has the advantage of high precision.

The SLA method is similar to the DLP method, but DLP uses ultraviolet light using a beam project, whereas the SLA method uses laser light.

In addition, the SLS method is a method of obtaining a molded article by irradiating a laser to a powder material to melt or partially melt the powder particles to induce bonding between the particles.

Poly-Jet method is a printing method in which material is sprayed through a nozzle like FDM method and then solidified by irradiating ultraviolet light like DLP method. , economical, and at the same time, has the advantage of securing a high level of precision and productivity.

The photocurable repair composition may include alumina, zirconia, a photoinitiator and an acrylate-based monomer.

The alumina (Al ₂ O ₃ ) is a biocompatible ceramic material having abrasion resistance and chemical stability.

The zirconia (ZrO ₂ ) is a biocompatible ceramic material having the best mechanical strength at room temperature, and there is no deformation or discoloration, so it can have the same effect as a natural tooth.

The alumina and zirconia may be in a powder form, and in the case of the zirconia powder, a zirconia powder stabilized with ceria (CeO ₂ ) may be used.

The ceria-stabilized zirconia powder exhibits an effect of improving durability by improving the flexural strength of the core.

The ceria-stabilized zirconia powder may be prepared by mixing ceria and zirconia powder, and a molar ratio of ceria to zirconia is preferably 1:1 to 15.

In addition, the average particle diameter of the alumina and zirconia powder may be 0.01 to 30 μm, preferably 0.1 to 20 μm, and more preferably 1 to 10 μm.

If the average particle diameter of the alumina and zirconia powder is out of the above range, a decrease in strength or abrasion resistance may occur.

The photocurable repair composition may include 10 to 100 parts by weight of zirconia based on 100 parts by weight of alumina.

Specifically, based on 100 parts by weight of alumina, 20 to 80 parts by weight of zirconia may be included, preferably 30 to 60 parts by weight, and more preferably 40 to 50 parts by weight.

When the alumina and zirconia are included in the above range, the flexural strength of the formed core is maximized, thereby remarkably improving durability.

In addition, the photocurable restoration composition may further include 10 to 100 parts by weight of yttria (Y ₂ O ₃ ) powder based on 100 parts by weight of alumina, and the average particle diameter of the yttria powder may be 0.01 to 30 μm. .

The photoinitiator is a component that is excited by ultraviolet (UV) or visible light to induce photopolymerization, and any photoinitiator commonly known in the art may be used without limitation.

In the present invention, the photoinitiator is camphorquinone, 2- (dimethylamino methacrylate) (2- (Dimethylamino methacrylates), phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (Phenylbis (2) , 4,6-trimethylbenzoyl) phosphine oxide) and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide) can do.

The photoinitiator may be included in an amount of 1 to 100 parts by weight, preferably 2 to 50 parts by weight, based on 100 parts by weight of alumina.

The acrylate-based monomer is bisphenol A-glycidyl methacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), ethylene glycol dimethacrylate (TGDMA), ethoxylate bisphenol A dimethacrylic Bis-EMA, urethane dimethacrylate (UDMA), dipentaerythritol pentacrylate monophosphate (PENTA), 2-hydroxyethyl methacrylate (HEMA) ), polyalkenic acid, biphenyl dimethacrylate (BPDM), glycerol phosphate dimethacrylate (GPDM) and 1,6-hexanediol diacrylate (1, 6-Hexanediol diacrylate) may be characterized in that at least one selected from the group consisting of.

Preferably, the acrylate-based monomer is urethane dimethacrylate (UDMA), 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA) and 1,6 -Hexanediol diacrylate (1,6-Hexanediol diacrylate) can be used.

The acrylate-based monomer may be included in an amount of 50 to 1,000 parts by weight, preferably 100 to 500 parts by weight, and more preferably 200 to 400 parts by weight based on 100 parts by weight of alumina.

The photocurable repair composition may further include at least one selected from an oligomer composed of an acrylate-based monomer and a polymer composed of an acrylate-based monomer.

The oligomers and polymers have the effect of maintaining the shape of the core, which is an output, when lamination and curing are performed using a 3D printer, and increase workability during sintering.

The sintering is performed by drying the core at a temperature of 300 to 700° C. for 1 to 30 minutes, maintaining it at a temperature of 800 to 1500° C. for 10 to 30 minutes, and then cooling it at a temperature of 300 to 700° C. for 1 to 10 minutes. It can be characterized as being.

The sintering condition corresponds to a condition capable of securing the strength of the core itself while forming a porous structure in the core.

The glass composition is based on 100 parts by weight of lanthanum oxide, 10 to 100 parts by weight of silica, 10 to 100 parts by weight of alumina, 10 to 100 parts by weight of boron oxide, 1 to 50 parts by weight of sodium oxide, 1 to 30 parts by weight of calcium oxide and It may be characterized in that it contains 1 to 30 parts by weight of magnesium oxide.

Preferably, based on 100 parts by weight of lanthanum oxide, 20 to 80 parts by weight of silica, 20 to 80 parts by weight of alumina, 20 to 70 parts by weight of boron oxide, 1 to 30 parts by weight of sodium oxide, 1 to 20 parts by weight of calcium oxide and oxide May contain 1 to 20 parts by weight of magnesium, more preferably, based on 100 parts by weight of lanthanum oxide, 30 to 70 parts by weight of silica, 30 to 70 parts by weight of alumina, 30 to 50 parts by weight of boron oxide, 1 to 20 parts by weight of sodium oxide. It may include 1 to 10 parts by weight of calcium oxide and 1 to 10 parts by weight of magnesium oxide.

The content range is a content range that can improve the penetration of the glass composition into the core to form a tensile force, and maximize the aesthetics and mechanical strength of the dental prosthesis.

In particular, the range of magnesium oxide corresponds to a range capable of maximizing penetration into the core, and the range of lanthanum oxide is a range that does not weaken brittleness while improving transparency by improving the esthetic of the dental prosthesis.

Here, the weight ratio of the sintered core to the applied glass composition may be 1: 0.01 to 10.

Specifically, the weight ratio of the sintered core to the applied glass composition may be preferably 1:0.1-5, more preferably 1:0.5-3.

When the weight ratio of the core and the glass composition is out of the above range, there may be problems in that the glass composition does not sufficiently penetrate into the pores formed inside the core, so that durability is reduced, or the glass composition in excess remains on the surface of the core, thereby reducing the aesthetics. there is.

The heat treatment is performed by drying at a temperature of 300 to 700 ° C for 1 to 10 minutes, maintaining at a temperature of 800 to 1500 ° C for 20 to 60 minutes, and then cooling at a temperature of 300 to 700 ° C for 1 to 10 minutes. can be done with

The heat treatment conditions correspond to conditions that do not require excessive time and high-temperature heat while improving strength by sufficiently penetrating the glass composition into the porous structure of the core by capillary action.

Hereinafter, examples and experimental examples will be described in detail to explain the present invention in detail. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art.

<Preparation Example 1> Preparation of photocurable restorative composition

Zirconia (ZrO ₂ ) (CF-Super, Z-Tech Co, USA) powder having an average particle size of 9.14 μm was added with ceria (CeO ₂ ) having an average particle size of 9.80 μm (Unocal Molycop, USA) as a phase-stabilizer 13 After adding and mixing in mol%, heat treatment was performed at 1,600° C. for 2 hours, cooled to 25° C. at a rate of 30° C./min, and then pulverized with a ball mill to prepare ceria-stabilized zirconia powder.

A ceramic composition was prepared by mixing the prepared ceria-stabilized zirconia powder with alumina powder (AM-21, Sumitomo Co, Japan) having a purity of 99.99% and an average particle size of 6.98 μm in a 3:7 weight ratio.

A photo-curable restoration composition for a 3D printer was prepared by mixing a photoinitiator and an acrylate-based monomer with the ceramic composition.

Components and contents used in the preparation are shown in Table 1 below.

composition type Preparation Example 1
(parts by weight) ceramic composition Alumina (Al2O3) 30 Zirconia (ZrO2) 70 photoinitiator camphorquinone 2 Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide
(Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide) 2 Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide
(Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide) 2 monomer 2-hydroxyethyl methacrylate (HEMA) 30 Triethylene glycol dimethacrylate (TEGDMA) 30 1,6-Hexanediol diacrylate 30 Urethane Dimethacrylate (UDMA) 30

<Preparation Example 2> Preparation of glass composition

38 wt % lanthanum oxide (La ₂ O ₃ ), 19 wt % silica (SiO ₂ ), 19 wt % alumina (Al ₂ O ³ ), 16 wt % boron oxide (B ₂ O ₃ ), 4 wt % % sodium oxide (Na ₂ O), 2 wt % calcium oxide (CaO), and 2 wt % magnesium oxide (MgO) were mixed to prepare a glass composition.

<Experimental Example 1> Measurement of decomposition temperature of UV curing polymer

The decomposition temperature of the photocurable repair composition for a 3D printer of Preparation Example 1 was measured using differential scanning calorimetry, which is shown in FIG. 1 .

As a result, it was confirmed that the polymer was decomposed at 316.5°C. After the core was printed, the prosthesis was manufactured so that the printed polymer was decomposed by maintaining it at 400°C for 20 minutes, leaving only pure ceramics.

<Example 1> Manufacturing of dental prosthesis using 3D printer

After scanning human teeth for prosthesis manufacturing, a model of the core was designed using CAD (Computer Aided Design).

Then, the photocurable repair composition of Preparation Example 1 is placed in a slurry tube of a 3D printer, the photocurable repair composition is laminated using a 3D printer (Illuminade), and cured by UV irradiation (at 405 nm for 30 seconds) By doing so, a core was formed.

The output core was put in a ceramic kiln, dried at 400°C for 20 minutes, raised to 1,150°C at a rate of 70°C/min, maintained at 1,150°C for 20 minutes, cooled to 500°C for 5 minutes, and a sintered core was obtained.

The sintered core was washed with tap water after adjusting the thickness to 0.5 mm using a diamond point.

The glass composition of Preparation Example 2 was mixed with distilled water on the core and applied in a weight ratio of 1:1 with the core, put in a ceramic kiln, dried at 500°C for 5 minutes, and then raised to 1,150°C at a rate of 70°C/min. and maintained for 30 minutes, and then cooled to 600° C. for 5 minutes to allow the glass composition to penetrate into the core.

Here, the vacuum started at 500 °C and was maintained at 1,150 °C for 7 minutes.

When the glass composition flowed into the inner surface of the core, it was cleanly removed without damage to the margin by sand blasting with alumina powder of 100 microns in size.

<Experimental Example 1> Evaluation of the physical properties of a dental prosthesis manufactured using a 3D printer

The strength of the manufactured dental prosthesis was measured through a three-point flexural strength test of ISO6872, and the results are shown in Table 2 and FIG. 2 below.

Maximum flexural load
[N] maximum flexural strength
[MPa] thickness
[mm] width
[mm] One 91.49 354,91 1.41 3.89 2 130.69 404.91 1.59 3.83 3 102.26 404.57 1.37 4.04 4 110.28 366,21 1.52 3.91 5 116,86 399.33 1.52 3.80 6 92.48 306.34 1.52 3.92 7 103.48 359.47 1.49 3.89 8 118.74 375.33 1.56 3.90 9 105.48 365.22 1.51 3.80 10 88.20 383.76 1.30 4.08 Average 106.00 372.01 1.48 3.91

As a result, the maximum flexural strength was shown as an average of 372.01 MPa, and it was confirmed that the prosthesis manufactured according to the present invention exhibited excellent strength.

Claims (8)

laminating and curing the photocurable restorative composition to form a core;
sintering the core; and
applying a glass composition to the surface of the sintered core and heat-treating it to penetrate the glass composition into the core;
The photocurable repair composition comprises alumina, zirconia, a photoinitiator and an acrylate-based monomer,
The photocurable repair composition comprises 40 to 50 parts by weight of zirconia based on 100 parts by weight of alumina,
The zirconia is zirconia stabilized with ceria (CeO ₂ ),
The ceria-stabilized zirconia has a molar ratio of ceria and zirconia of 1:1 to 15,
The weight ratio of the sintered core to the applied glass composition is 1: 0.5 to 3,
The glass composition is based on 100 parts by weight of lanthanum oxide, 30 to 70 parts by weight of silica, 30 to 70 parts by weight of alumina, 30 to 50 parts by weight of boron oxide, 1 to 20 parts by weight of sodium oxide, 1 to 10 parts by weight of calcium oxide and A method of manufacturing a dental prosthesis, comprising 1 to 10 parts by weight of magnesium oxide.
According to claim 1,
The forming of the core is a method of manufacturing a dental prosthesis, characterized in that the photocurable restorative composition is laminated with a 3D printer and cured.
delete According to claim 1,
The photoinitiator is camphorquinone, 2- (dimethylamino methacrylate) (2- (Dimethylamino methacrylates), phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (Phenylbis (2,4,6- Trimethylbenzoyl) phosphine oxide) and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide) Preparation of a dental prosthesis comprising at least one selected from method.
According to claim 1,
The acrylate-based monomer is bisphenol A-glycidyl methacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), ethylene glycol dimethacrylate (TGDMA), ethoxylate bisphenol A dimethacrylic Late (Bis-EMA), urethane dimethacrylate (UDMA), dipentaerythritol pentacrylate monophosphate (PENTA), 2-hydroxyethyl methacrylate (HEMA) ), polyalkenic acid, biphenyl dimethacrylate (BPDM), glycerol phosphate dimethacrylate (GPDM) and 1,6-hexanediol diacrylate (1, 6-Hexanediol diacrylate), a method of manufacturing a dental prosthesis, characterized in that at least one selected from the group consisting of. delete delete delete

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