KR101556902B1 - Ceramic ingot for artificial tooth and manufacturing method of the same - Google Patents

Abstract

The present invention relates to a ceramic ingot for an artificial tooth which includes 15.0~40.0 mol% of SiO_2, 25.0-45.0 mol% of CaO, 10.0-30.0 mol% of MgO, 1.0-20.0 mol% of TiO_2, 1.0-15.0 mol% of P_20_5, 0.01-5.0 mol% of CaF_2, and 0.01-5.0 mol% of ZrO_2, and to a method for manufacturing the same. According to the present invention, the ceramic ingot for an artificial tooth has thermal conductivity similar with thermal conductivity of a real tooth and thus can prevent tooth ache caused by cold, has transparency and the color which are similar to transparency and the color of the real tooth and thus is less visibly different from the real tooth; has strength and hardness which are very similar to strength and hardness of the real tooth and thus can prevent the real tooth from being worn, and has excellent durability.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic ingot for artificial teeth having excellent durability and a manufacturing method thereof.

The present invention relates to a ceramic ingot for artificial teeth and a method of manufacturing the same. More particularly, the present invention relates to a ceramic ingot for artificial teeth, and more particularly to a ceramic ingot for artificial teeth which is similar in thermal conductivity to natural teeth and can suppress tooth whitening phenomenon and exhibits translucency and color similar to natural teeth, The present invention also relates to a ceramic ingot for artificial teeth having excellent durability and a method of manufacturing the same.

Tooth restoration is the procedure of restoring teeth that are severely damaged by dental caries or trauma. That is, the restoration of the damaged tooth is made with a standard shape and applied to the teeth. Dental restorations are made of metal or resin, but they do not satisfy strength and aesthetics at the same time, discoloration and fracture occur due to color stability and strength decrease, and they are disadvantageous in aesthetically not good in the upper anterior part as an esthetically important part have.

Particularly, precious metal alloys such as gold (Au) alloys have been used for dental restorations such as veneers, inlay, onlay, stump, and crown. However, precious metal alloys such as gold (Au) alloys are expensive, and recently gold (Au) values have risen sharply in accordance with the global trend, and the cost of manufacturing noble metal alloy restorations is increasing steeply . In addition, since the noble metal alloy is different in color from the natural tooth, there are many users who are reluctant to use it for aesthetic reasons.

There is an attempt to use inexpensive metal alloys instead of noble metal alloys as tooth restorations, but metallic alloys are controversial to human health.

As the economy improves, there is a growing interest in improving the esthetics. In order to restore teeth, it is necessary to develop a ceramic ingot for artificial teeth that has higher strength, better aesthetics and higher biocompatibility than ordinary metal and resin types However, up to now, satisfactory level of artificial tooth ceramic ingots have not been commercialized.

In recent years, research has been conducted to produce dental restorations with ceramics capable of producing the appearance corresponding to natural teeth as much as possible for aesthetic reasons.

Glass-ceramics are mainly used for such tooth restoration. For example, U.S. Patent No. 4,798,536 discloses a restoration comprising a ceramic dental restoration made of limestone glass-ceramics containing 45 wt% or more of leucite as a crystalline phase.

A tooth restoration made of glass-ceramics is represented as a glass-ceramic which is present in such a way that at least one crystal phase is distributed on the glass, and the glass-ceramics can be obtained by subjecting the amorphous primary glass to a controlled partial crystallization treatment.

However, the conventional general glass-ceramic tooth restoration can be used for veneers, inlays, onlay, etc. However, it can not be used for crowns of molar teeth due to its weak strength There are disadvantages.

In addition, since the glass-ceramic tooth restoration sold in Korea is expensive, it is a heavy burden on the user.

In addition, the glass-ceramic tooth restoration has a complicated manufacturing process, which makes it difficult to mass-produce it, and the reproducibility is low.

United States Patent Number 4,798,536 Korea Patent Registration No. 10-1160128 Korea Patent Registration No. 10-1290127

The problem to be solved by the present invention is that the thermal conductivity is similar to that of a natural tooth, the tooth whitening phenomenon can be suppressed, the translucency and color similar to that of a natural tooth are manifested, And thus it is possible to suppress abrasion of the natural teeth and to provide a ceramic ingot for artificial teeth having excellent durability.

Another object to be solved by the present invention is to provide a manufacturing method of a toothbrush which is less toxic to humans and uses natural raw materials because it uses natural raw materials, Ceramic ingots can be manufactured and can be used not only for veneers, inlays, onlay, but also for crown of molar teeth since they have higher strength than general tooth restoration materials. And a method of manufacturing a ceramic ingot for artificial teeth.

The present invention, SiO ₂ 15.0~40.0 mol%, CaO 25.0~45.0% by mole, mole% 10.0~30.0 MgO, TiO ₂ 1.0~20.0 mol%, P ₂ O ₅ 1.0~15.0% by mole, CaF ₂ 0.01~5.0 mol % And ZrO _{2 in an} amount of 0.01 to 5.0 mol% based on the total weight of the ceramic ingot.

The artificial tooth ceramic ingot may further include 0.01 to 5.0 mol% of Ca ₅ (PO ₄ ) ₃ (OH).

Further, the ceramic ingot for the artificial tooth may further comprise a _{3Al 2 O 3 · 2SiO 2 0.01~3.0} % by mole.

The artificial tooth ceramic ingot may further contain 0.01 to 5.0 mol% of MgAl ₂ O ₄ .

The artificial tooth ceramic ingot may further contain 0.001 to 3.0 mol% of Fe ₂ O ₃ .

In addition, the present invention, (a) synthetic ceramic ingot is SiO ₂ 15.0~40.0% mol, CaO 25.0~45.0% by mole, mole% 10.0~30.0 MgO, TiO ₂ 1.0~20.0% mol, P ₂ O ₅ for the teeth 1.0 ~15.0 mol%, CaF ₂ 0.01~5.0 mol%, and _{ZrO 2 0.01~5.0 SiO 2, CaCO 3} , MgO to contain by _{mole%, TiO 2, H 3 PO} 4, CaF 2 , and ZrO ₂ ingredients are weighed the starting materials (C) heating and quenching the dried product to form a frit to form a frit; (d) pulverizing the frit; (e) heating the pulverized product to a frit (F) shaping the softened resultant into a mold to be molded in the form of an ingot and slowly cooling the resultant, and (g) heat-treating the resultant of the molding for crystallization to form a synthetic ceramic And a step of forming an ingot. The present invention also provides a method of manufacturing a ceramic ingot for artificial teeth.

The starting material may further contain 0.01 to 5.0 mol% Ca ₅ (PO ₄ ) ₃ (OH).

Further, the starting material may further include a _{3Al 2 O 3 · 2SiO 2 0.01~3.0} % by mole.

In addition, the starting material may further contain 0.01 to 5.0 mol% of MgAl ₂ O ₄ .

In addition, the starting material may further contain 0.001 to 3.0 mol% of Fe ₂ O ₃ .

The method for producing a ceramic ingot for artificial teeth may further include a step of coating Li ₂ CO ₃ on the surface of the resultant of molding obtained in step (f) before step (g) after step (f).

The heat treatment in the step (c) may include heating and maintaining a first temperature of 300 to 600 캜, raising and maintaining a temperature of 700 to 1100 캜 to a second temperature, And maintaining and drying the dried product.

The heating in the step (e) is preferably performed at a temperature of 1250 to 1500 ° C.

In the step (f), it is preferable that the mold is maintained at a temperature of 400 to 600 ° C for molding into an ingot form.

In the step (g), the heat treatment for crystallization is preferably performed at a temperature of 620 to 780 캜.

According to the ceramic ingot for artificial teeth according to the present invention, since it has a higher strength than a general tooth restoration, it can be used not only for a veneer, an inlay, and an onlay but also for a crown of a molar Can be used.

The ceramic ingot for artificial teeth according to the present invention, unlike the conventional metal and resin injection tube, is esthetically excellent as a ceramic, has excellent biocompatibility, has high strength and toughness.

In addition, the ceramic ingot for artificial teeth according to the present invention has a thermal conductivity similar to that of a natural tooth, so that the tooth whitening phenomenon can be suppressed, the translucency and color similar to natural teeth are exhibited, The propagation of bacteria such as streptococcus mutans is suppressed and the strength and hardness are very similar to natural teeth, so that abrasion of natural teeth is suppressed and durability is excellent.

Further, according to the method for producing a ceramic ingot for artificial teeth of the present invention, since a natural raw material is used, the harmfulness to human body is small, and a low cost natural raw material is used, It is possible to manufacture a reliable ceramic ingot for artificial teeth having reproducibility.

1 is a view showing a process of heat-treating a starting material to be melted.
2 is a graph showing the results of differential scanning calorimetry (DSC) of the ingot prepared according to the experimental example (the ingot before the application of Li ₂ CO ₃ as the ingot demolded from the mold).
3 is a view showing an X-ray diffraction (XRD) pattern of a ceramic ingot for artificial teeth prepared according to Experimental Example.
4A and 4B are scanning electron microscope (SEM) photographs showing the microstructure of a ceramic ingot for artificial teeth prepared according to Experimental Example.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not.

Ceramic ingot for artificial teeth is SiO ₂ 15.0~40.0 mol%, CaO 25.0~45.0% by mole, mole% 10.0~30.0 MgO, TiO ₂ 1.0~20.0 mol%, P ₂ O ₅ 1.0~15.0% by mole, CaF ₂ 0.01~ 5.0 mol% of ZrO _{2 and} 0.01 to 5.0 mol% of ZrO ₂ .

SiO ₂ is a material forming a glass matrix and has a cohesive force and an adhesive force, and serves as a binder for bonding materials. When the raw materials are mixed and heat-treated, SiO ₂ softens to form a glass phase to bind the particles. SiO ₂ is preferably contained in the artificial tooth ceramic ingot in an amount of 15.0 to 40.0 mol%.

CaO contains a large amount of calcium (Ca) in natural teeth and helps to develop translucency and color similar to natural teeth. When the content of CaO is less than 25.0 mol%, there is a limit in expressing light transmittance and color similar to natural teeth, and the content of CaO is 45.0 mol %, The strength of the ceramic ingot for artificial teeth can be reduced.

MgO serves to enhance the durability against thermal degeneration. MgO is preferably contained in the artificial tooth ceramic ingot in an amount of 10.0 to 30.0 mol%.

TiO ₂ is used as nucleating agent in the formation of free crystals. TiO ₂ is known to be harmless to the human body because of its excellent biocompatibility. TiO ₂ is an effective component for expressing similar colors in living teeth and shows an efficient performance in coloring during dental processing. TiO ₂ is preferably contained in the artificial tooth ceramic ingot in an amount of 1.0 to 20.0 mol%.

P ₂ O ₅ is a substance that forms a glass matrix and contains phosphorus (P), which is contained in natural teeth. It has a translucency and color similar to that of natural teeth, But also inhibits the growth of bacteria such as Streptococcus mutans. P ₂ O ₅ is from 1.0 to 15.0 in the artificial teeth for ceramic ingot it is preferable to be contained by mole%, P ₂ O ₅ 1.0 When the amount of the mol% is less than the translucent similar to the effect of the natural tooth for inhibiting bacteria and color , And when the content of P ₂ O ₅ is more than 15.0 mol%, the strength of the ceramic ingot for artificial teeth can be reduced.

CaF ₂ plays a role of flux, so if it is mixed with raw materials and heat-treated, it promotes fluidity, which enables heat treatment at low temperature, helps formation of glass phase, and improves chemical durability. It is preferable that CaF ₂ is contained in the artificial tooth ceramic ingot in an amount of 0.01 to 5.0 mol%.

ZrO ₂ affects the mechanical properties of ceramic ingots for artificial teeth, resulting in improved mechanical properties such as fracture toughness and flexural strength. ZrO ₂ is preferably contained in an amount of 0.01 to 5.0 mol% in the artificial tooth ceramic ingot. When the content of ZrO ₂ is too large, the color of the ceramic ingot for artificial teeth may become turbid and the light transmittance may be significantly reduced.

The artificial tooth ceramic ingot may further include 0.01 to 5.0 mol% of Ca ₅ (PO ₄ ) ₃ (OH). The 3Al ₂ O ₃ · If 2SiO ₂ is presented containing the same as the body's bones or teeth main component and has excellent biocompatibility, and is an advantage that can be readily compatible with the living tissue it can be enhanced in strength of the ceramic ingot for artificial teeth. The Ca ₅ (PO ₄ ) ₃ (OH) is preferably contained in the artificial tooth ceramic ingot in an amount of 0.01 to 5.0 mol%.

Further, the ceramic ingot for the artificial tooth may further comprise a _{3Al 2 O 3 · 2SiO 2 0.01~3.0} % by mole. When the ₂ O ₃ · 2SiO ₂ is 3Al be contained reducing the thermal deformation and the strength of the ceramic ingot for artificial teeth can be enhanced. The 3Al ₂ O ₃ · 2SiO ₂ It is preferable to be contained 0.01~3.0 mol% in the ceramic ingot for artificial teeth.

The artificial tooth ceramic ingot may further contain 0.01 to 5.0 mol% of MgAl ₂ O ₄ . When MgAl ₂ O ₄ is contained, thermal deformation is reduced and the strength of the ceramic ingot for artificial teeth can be enhanced. The MgAl ₂ O ₄ is preferably contained in the artificial tooth ceramic ingot in an amount of 0.01 to 5.0 mol%.

The artificial tooth ceramic ingot may further contain 0.001 to 3.0 mol% of Fe ₂ O ₃ . Fe ₂ O ₃ is added to control the color of ceramic ingots for artificial teeth similar to natural teeth, and it also serves to improve the mechanical properties of ceramic ingots for artificial teeth. The Fe ₂ O ₃ is preferred that to be contained 0.001~3.0 mol% in the ceramic ingot for artificial teeth, similar to the case the content of Fe ₂ O ₃ is less than 0.001 mol%, the color of ceramic ingot for artificial teeth and natural teeth If the content of Fe ₂ O ₃ is more than 3.0 mol%, the color of the ceramic ingot for artificial teeth may be red, which may cause a problem in that the color of the natural tooth may be different from that of the natural tooth.

The ceramic ingots for artificial teeth can be used to make veneers, inlays, onlays, crowns, stumps, facets, artificial teeth, The object for a tooth can be selectively produced.

Hereinafter, a method of manufacturing a ceramic ingot for artificial teeth according to a preferred embodiment of the present invention will be described.

In order to prepare a ceramic ingot for artificial teeth, raw materials of SiO ₂ , CaCO ₃ , MgO, TiO ₂ , H ₃ PO ₄ , CaF ₂ and ZrO ₂ are weighed and prepared as a starting material. H ₃ PO ₄ is changed to P ₂ O ₅ in the subsequent heat treatment process and CaCO ₃ is changed into CaO in the subsequent heat treatment process. Each raw material is weighed, and finally, the ceramic ingot for artificial tooth formed is SiO ₂ 15.0 to 40.0 mol% CaO 25.0 to 45.0 mol% MgO 10.0 to 30.0 mol% TiO ₂ 1.0 to 20.0 mol% P ₂ O ₅ 1.0 to 15.0 mol% CaF ₂ 0.01 to 5.0 mol% ZrO ₂ 0.01 To 5.0 mol% of the starting materials. The starting materials SiO ₂ 15.0~40.0% by mole In one example, CaCO ₃ 25.0~45.0% by mole, mole% 10.0~30.0 MgO, TiO ₂ 1.0~20.0% mol, H ₃ PO ₄ 1.0~15.0% by mole, CaF ₂ 0.01 to 5.0 mol%, and ZrO _{2 in an} amount of 0.01 to 5.0 mol%.

SiO ₂ is a material forming a glass matrix and has a cohesive force and an adhesive force, and serves as a binder for bonding materials. When the raw materials are mixed and heat-treated, SiO ₂ softens to form a glass phase to bind the particles. SiO ₂ is preferably contained in the artificial tooth ceramic ingot in an amount of 15.0 to 40.0 mol%.

The CaCO ₃ is a source material for providing CaO, which is a component of a ceramic ingot for artificial teeth. The CaCO ₃ is converted into CaO by volatilizing the carbon dioxide (CO ₂ ) component as a gas in a heat treatment process to be described later. CaO contains a large amount of calcium (Ca) in natural teeth and helps to develop translucency and color similar to natural teeth. When the content of CaO is less than 25.0 mol%, there is a limit in expressing light transmittance and color similar to natural teeth, and the content of CaO is 45.0 mol %, The strength of the ceramic ingot for artificial teeth can be reduced.

MgO serves to enhance the durability against thermal degeneration. MgO is preferably contained in the artificial tooth ceramic ingot in an amount of 10.0 to 30.0 mol%.

TiO ₂ is used as nucleating agent in the formation of free crystals. TiO ₂ is known to be harmless to the human body because of its excellent biocompatibility. TiO ₂ is an effective component for expressing similar colors in living teeth and shows an efficient performance in coloring during dental processing. TiO ₂ is preferably contained in the artificial tooth ceramic ingot in an amount of 1.0 to 20.0 mol%.

The H ₃ PO ₄ is a source material for providing P ₂ O ₅ , which is a component of a ceramic ingot for artificial teeth. The H ₃ PO ₄ is changed to P ₂ O ₅ after the heat treatment process described below. P ₂ O ₅ is a substance that forms a glass matrix and contains phosphorus (P), which is contained in natural teeth. It has a translucency and color similar to that of natural teeth, But also inhibits the growth of bacteria such as Streptococcus mutans. P ₂ O ₅ is from 1.0 to 15.0 in the artificial teeth for ceramic ingot it is preferable to be contained by mole%, P ₂ O ₅ 1.0 When the amount of the mol% is less than the translucent similar to the effect of the natural tooth for inhibiting bacteria and color , And when the content of P ₂ O ₅ is more than 15.0 mol%, the strength of the ceramic ingot for artificial teeth can be reduced.

CaF ₂ plays a role of flux, so if it is mixed with raw materials and heat-treated, it promotes fluidity, which enables heat treatment at low temperature, helps formation of glass phase, and improves chemical durability. It is preferable that CaF ₂ is contained in the artificial tooth ceramic ingot in an amount of 0.01 to 5.0 mol%.

ZrO ₂ affects the mechanical properties of ceramic ingots for artificial teeth, resulting in improved mechanical properties such as fracture toughness and flexural strength. ZrO ₂ is preferably contained in an amount of 0.01 to 5.0 mol% in the artificial tooth ceramic ingot. When the content of ZrO ₂ is too large, the color of the ceramic ingot for artificial teeth may become turbid and the light transmittance may be significantly reduced.

The starting material may further contain 0.01 to 5.0 mol% Ca ₅ (PO ₄ ) ₃ (OH). The 3Al ₂ O ₃ · If 2SiO ₂ is to be added to the same as that of the human bone or tooth main component and has excellent biocompatibility, and is an advantage that can be readily compatible with the living tissue can be enhanced in strength of the ceramic ingot for artificial teeth.

Further, the starting material may further include a _{3Al 2 O 3 · 2SiO 2 0.01~3.0} % by mole. When the ₂ O ₃ · 2SiO ₂ is 3Al be added to promote the crystallization is reduced and the thermal deformation, and the strength of the ceramic ingot for artificial teeth can be enhanced.

In addition, the starting material may further contain 0.01 to 5.0 mol% of MgAl ₂ O ₄ . When MgAl ₂ O ₄ is added, the crystallization is promoted and thermal deformation is reduced, and the strength of the ceramic ingot for artificial teeth can be enhanced.

In addition, the starting material may further contain 0.01 to 3.0 mol% of F ₂ O ₃ . Fe ₂ O ₃ is added to control the color of ceramic ingots for artificial teeth similar to natural teeth, and it also serves to improve the mechanical properties of ceramic ingots for artificial teeth. The Fe ₂ O ₃ is preferred that to be contained 0.001~3.0 mol% in the ceramic ingot for artificial teeth, similar to the case the content of Fe ₂ O ₃ is less than 0.001 mol%, the color of ceramic ingot for artificial teeth and natural teeth If the content of Fe ₂ O ₃ is more than 3.0 mol%, the color of the ceramic ingot for artificial teeth may be red, which may cause a problem in that the color of the natural tooth may be different from that of the natural tooth.

The starting materials are mixed and dried. The drying is preferably performed at a temperature of about 100 to 400 DEG C on a hot plate until the liquid component is removed and only the powder is left.

The dried product is placed in a crucible made of a material such as platinum or alumina (Al ₂ O ₃ ), the crucible is charged into the furnace, and the starting material is heat treated to be melted and quenched to form a frit. 1 is a view illustrating a heat treatment process for forming a ceramic ingot for artificial teeth according to a preferred embodiment of the present invention. Hereinafter, the heat treatment process will be described in more detail.

Referring to FIG. 1, a crucible containing a starting material is charged into a furnace. The temperature of the furnace is raised to the first temperature and maintained for a predetermined time (for example, 10 minutes to 12 hours) using the heating means provided in the furnace (t1 section in Fig. 1). In this case, the rate of temperature rise of the furnace is preferably about 1 to 50 ° C / min. If the rate of temperature rise of the furnace is too slow, it takes a long time to decrease the productivity. If the rate of temperature rise of the furnace is too fast, It is preferable to increase the temperature of the furnace at a heating rate within the above range. The first temperature is preferably about 300 to 600 ° C. If the temperature is maintained at the first temperature, an organic substance component, which is an impurity, is burned and can be discharged to the outside, and carbon dioxide (CO ₂ ) gas can be generated and discharged to the outside. If the organic component and the carbon dioxide (CO ₂ ) remain, the property of the frit obtained after the heat treatment may not be good, so that it is maintained at the first temperature for a certain period of time.

The temperature is raised from the first temperature to the second temperature and maintained for a predetermined time (for example, 10 minutes to 12 hours) (t2 section in FIG. 1). At this time, the rate of temperature rise of the furnace is preferably about 1 to 50 DEG C / min. The second temperature is preferably about 750 to 1100 ° C. When the temperature is maintained at the second temperature, carbon dioxide (CO ₂ ) gas is generated and can be discharged to the outside. When carbon dioxide (CO ₂ ) remains, the pores are formed and the physical properties of the frit obtained after the heat treatment may not be good, so that the carbon dioxide (CO ₂ ) is maintained at the second temperature for a certain period of time.

The temperature of the furnace is raised to the third temperature (target heat treatment temperature) and maintained for a predetermined time (for example, 10 minutes to 12 hours) (t3 section in FIG. 1). At this time, the rate of temperature rise of the furnace is preferably about 1 to 50 DEG C / min. When the temperature of the furnace reaches a target third temperature (for example, 1350 to 1550 ° C), it is maintained at the third temperature (t3 section in FIG. 2) to melt the dried product.

Quench the heat treated product. The quenching may be carried out in a water-immersed manner. The internal strength of the frit is strengthened by quenching the heat treated product.

The obtained frit can be pulverized by quenching. The pulverization may be performed by various methods such as ball milling, jet milling, induction milling, jaw crusher, pulverizer and disk mill.

The ball milling process is taken as an example. The frit is charged into a ball milling machine and rotated at a constant speed using a ball miller to mechanically pulverize the raw material particles and mix them uniformly. The ball used for ball milling may be a ceramic ball such as zirconia (ZrO ₂ ) or alumina (Al ₂ O ₃ ), and the balls may be all the same size or may be used together with balls having two or more sizes It is possible. The size of the balls, the milling time, and the rotation speed per minute of the ball miller are adjusted so as to be crushed to the target particle size. For example, in consideration of the size of the frit particles, the size of the balls may be set in a range of about 1 mm to 30 mm, and the rotational speed of the ball miller may be set in a range of about 50 to 1000 rpm. The ball milling is performed for 10 minutes to 48 hours considering the size of the target particle. By ball milling, the frit is pulverized into fine sized particles and has a uniform particle size distribution.

The frit is placed in a crucible made of a material such as platinum, alumina (Al ₂ O ₃ ) and heated to soften the frit. Here, softening means that the raw material is changed into a liquid state viscous material state, not a solid state. The heating is preferably performed at a temperature of about 1250 to 1500 DEG C for a predetermined time (for example, 10 minutes to 12 hours). At this time, it is preferable that the heating rate to the heating temperature for softening is about 1 to 50 ° C / min. If the heating rate is too slow, it takes a long time to decrease the productivity and if the heating rate is too fast, Since thermal stress may be applied, it is preferable to raise the temperature at the temperature raising rate within the above range.

The softened resultant is poured into a mold to be molded and molded into an ingot. At this time, it is preferable that the mold maintains a temperature of about 400 to 600 DEG C for forming the ingot shape. The holding temperature for forming the ingot shape is preferably about 400 to 600 ° C in consideration of the diffusion of particles and necking among the particles. When the holding temperature is too high, the mechanical properties If the holding temperature is too low, the mechanical properties of the ingot to be formed may be poor, so it is preferable to keep the temperature within the above range. The mold may be a mold made of graphite. The mold is a mold having a shape to be formed (molded), and a tooth shape, a block shape, or the like is selected and used according to the intended use. The holding time for forming the ingot shape is preferably about 10 minutes to 12 hours.

When the mold is formed into an ingot shape, the temperature of the mold is gradually cooled (slowly cooled), and then the mold is demolded. Molded products formed in the mold are formed to be formed (shaped), and have a shape suitable for the purpose of use, such as a tooth shape and a block shape.

The step of applying Li ₂ CO ₃ to the surface of the resultant molded product thus obtained can be performed. Coating method immerse the molded results in Li ₂ CO ₃ solution, Li ₂ CO ₃ solution to be used ppuryeoju the surface forming the result as a spray method, or a method applying the Li ₂ CO ₃ solution to the surface forming the result as brushes etc. have. The Li ₂ CO ₃ solution may be a solution in which Li ₂ CO ₃ is added to a solvent such as ethanol or methanol. The Li ₂ CO ₃ is the carbon dioxide (CO ₂₎ component in the heat treatment process for crystallization, which will be described later is volatilized into the gas (gas) and to be changed to Li ₂ O, in the heat treatment process for crystallization, which will be described later Li ₂ O is formed resulting And diffuses into the inside. The mechanical properties of the ceramic ingot for artificial teeth can be improved by applying Li ₂ CO ₃ to the surface of the molded product and there is an advantage that the light transmittance and color of the artificial tooth ceramic ingot can be expressed similarly to natural teeth. After coating the resultant product with Li ₂ CO ₃ , the drying process is carried out. The drying process is preferably performed at a temperature of about 40 to 150 DEG C for 10 minutes to 48 hours. The content of Li ₂ CO ₃ applied to the surface of the molded product is preferably about 0.0001 to 3 parts by weight based on 100 parts by weight of the molded product.

A heat treatment process is performed on the molded product (ingot) for crystallization. The heat treatment for crystallization is preferably performed at a temperature of about 620 to 780 캜 for 10 minutes to 12 hours. At this time, it is preferable that the rate of temperature rise to the heat treatment temperature for crystallization is about 0.1 to 20 DEG C / min. If the temperature increase rate is too slow, it takes a long time to decrease the productivity and if the temperature increase rate is too fast, Since thermal stress may be applied, it is preferable to raise the temperature at the temperature raising rate within the above range. The inside of the ingot is crystallized by the heat treatment step, and the mechanical strength of the ingot is increased by the crystallization. After the heat treatment for crystallization, it is preferable to cool slowly (slow cooling) to room temperature in the same manner as natural cooling.

After the heat treatment for crystallization is performed, the ceramic ingot for artificial teeth may be polished to impart luster and barrel processing may be performed to remove the microscopic burr. A barrel polishing machine or the like may be used for the barrel processing.

Hereinafter, experimental examples according to the present invention will be specifically shown, and the present invention is not limited to the following experimental examples.

<Experimental Example>

SiO ₂ , CaCO ₃ , MgO, TiO ₂ , H ₃ PO ₄ , CaF ₂ and ZrO ₂ raw materials were weighed and prepared as starting materials for the production of artificial tooth ceramic ingots. H ₃ PO ₄ was changed to P ₂ O ₅ in the subsequent heat treatment process and CaCO ₃ was changed into CaO in the subsequent heat treatment process. Each of the raw materials was weighed and the finally formed ceramic ingot for artificial tooth was SiO ₂ 24.8 mol%, CaO 28.9 mole%, MgO 11.3 mol%, TiO ₂ 14.7% mol, P ₂ O ₅ 16.3 mol%, CaF ₂ were weighed of each raw material to contain 1.8 mol%, and ZrO _2, 2.2 mol% of the starting material Lt; / RTI &gt; SiO ₂ , CaCO ₃ , MgO, TiO ₂ , CaF ₂ and ZrO ₂ were added to a crucible containing ethanol and stirred for 1 hour by using a magnetic bar. While H ₃ PO ₄ was gradually dropped, When the gas was not released, the silver foil was covered and agitated for 10 hours to become a gel state.

The starting material in gel form was dried on a hot plate. The drying was carried out at a temperature of about 350 ° C for 3 hours until the liquid component was removed and only the powder remained.

The dried product was placed in a crucible made of alumina (Al ₂ O ₃ ), and the crucible was charged into a furnace to heat-treat the starting material to be melted and quenched to form a frit. More specifically, a crucible containing the dried product is charged into a furnace, and the temperature of the furnace is raised to a first temperature (400 ° C) at a heating rate of 10 ° C / min using a heating means provided in the furnace, The temperature of the furnace was raised to a second temperature (900 ° C) at a heating rate of 10 ° C / min, maintained at a second temperature for 1 hour, and the temperature of the furnace was maintained at 10 ° C / min The temperature was raised to the third temperature (1450 ° C) at a heating rate and maintained at the third temperature for 2 hours to melt the starting material. The result of the heat treatment was quenched to obtain a frit. The quenching was carried out in a manner of adding to room temperature distilled water.

The frit obtained by quenching was pulverized. The pulverization was comminuted using a Jaw Crusher, pulverized using a pulverizer and disk mill, and pulverized using a pulverizer and disk mill , And sieved with a 325 mesh (45 mu m) sieve.

The ground frit was placed in an alumina crucible and heated to soften the frit. The heating was carried out at a temperature of 1350 DEG C for 1 hour. The heating rate to the heating temperature was about 10 ° C / min.

The softened result was poured into a graphite mold to form an ingot. At this time, the mold was maintained at a temperature of 500 DEG C for forming an ingot, and the softened product was put in a mold and held at a temperature of 500 DEG C for 1 hour.

After maintaining the mold at 500 DEG C for 1 hour, the temperature of the mold was lowered and then demolded in the mold.

The ingot surface thus obtained was coated with Li ₂ CO ₃ . As a coating method, a method of immersing an ingot in a Li ₂ CO ₃ solution was used, and the Li ₂ CO ₃ solution was a solution in which Li ₂ CO ₃ was added to ethanol. After the ingot surface was coated with Li ₂ CO ₃ , a drying process was performed. The drying process was performed at a temperature of 60 ° C. for 4 hours.

The ingot was subjected to a heat treatment process for crystallization. The heat treatment for crystallization was carried out at a temperature of 700 ° C for 1 hour. At this time, the rate of temperature rise to the heat treatment temperature for crystallization was about 1 ° C / min, and after the heat treatment for crystallization, the temperature was naturally cooled to room temperature.

The physical properties of the ceramic ingots for artificial teeth prepared as described above and the physical properties of natural teeth are shown in Table 1 below.

Ceramic ingot for artificial teeth Natural tooth Density (g / cm3) 2.74 3.0 Thermal conductivity (w / mk) 1.0 0.9 Bending Strength (MPa) 154 60 Vickers hardness (GPa) 3.41 3.7

As shown in Table 1, it can be seen that the density, the thermal conductivity, the bending strength and the Vickers hardness of the ceramic ingot for artificial tooth prepared according to the experimental example and the natural tooth are very similar.

2 is a graph showing the results of differential scanning calorimetry (DSC) of the ingot prepared according to the experimental example (the ingot before the application of Li ₂ CO ₃ as the ingot demolded from the mold).

3 is a view showing an X-ray diffraction (XRD) pattern of a ceramic ingot for artificial teeth prepared according to Experimental Example.

4A and 4B are scanning electron microscope (SEM) photographs showing the microstructure of a ceramic ingot for artificial teeth prepared according to Experimental Example.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, This is possible.

Claims (12)

SiO ₂ 15.0~40.0 mol%, CaO 25.0~45.0 mol%, MgO 10.0~30.0 mol%, TiO ₂ 1.0~20.0% mol, P ₂ O ₅ 1.0~15.0% by mole, CaF ₂ 0.01~5.0 mol%, and ZrO ₂ 0.01 to 5.0 mol%, based on the total weight of the ceramic ingot.
The artificial tooth ceramic ingot according to claim 1, further comprising 0.01 to 5.0 mol% of Ca ₅ (PO ₄ ) ₃ (OH).
According to claim _{1, 3Al 2 O 3 · 2SiO 2} 0.01~3.0 ceramic ingot for the artificial tooth according to claim 1, further comprising a mole%.
The ceramic ingot for artificial teeth according to claim 1, further comprising 0.01 to 5.0 mol% of MgAl ₂ O ₄ .
The artificial tooth ceramic ingot according to claim 1, further comprising 0.001 to 3.0 mol% Fe ₂ O ₃ .
(a) The ceramic ingot for artificial teeth comprises 15.0 to 40.0 mol% of SiO _2, 25.0 to 45.0 mol% of CaO, 10.0 to 30.0 mol% of MgO, 1.0 to 20.0 mol% of TiO ₂ , 1.0 to 15.0 mol% of P ₂ O ₅ , ₂ 0.01 to 5.0 0.01 to 5.0 mol%, and ZrO ₂ are weighed to _{SiO 2, CaCO 3, MgO,} TiO 2, H 3 PO 4, CaF 2 , and ZrO ₂ raw material to contain the mole% of the steps of preparing as the starting material;
(b) drying said starting material;
(c) heat treating and quenching the dried product to form a frit;
(d) grinding the frit;
(e) heating the pulverized product to soften the frit;
(f) pouring the softened resultant into a mold to be molded and molding the resultant into an ingot shape and gradually cooling the mold; And
(g) forming a ceramic ingot for artificial teeth by heat-treating the result of molding to crystallize the ceramic ingot.
[7] The method according to claim 6, wherein the starting material further comprises 0.01 to 5.0 mol% Ca ₅ (PO ₄ ) ₃ (OH).
7. The method of claim 6 wherein the starting material is 3Al ₂ O ₃ · 2SiO ₂ The process for producing a ceramic ingot for the artificial tooth according to claim 1, further including 0.01~3.0 mol%.
7. The method of claim 6 wherein the starting material is MgAl ₂ O ₄ The process for producing a ceramic ingot for the artificial tooth according to claim 1, further including 0.01~5.0 mol%.
The method according to claim 6, wherein the starting material further comprises 0.001 to 3.0 mol% of Fe ₂ O ₃ .
7. The method of claim 6, further comprising, before step (g) after step (f)
Further comprising the step of applying Li ₂ CO ₃ to the surface of the molded product obtained in the step (f).
7. The method of claim 6, wherein the heat treatment in step (c)
Raising and maintaining a first temperature of 300 to 600 ° C;
Raising and maintaining a second temperature of 700 to 1100 캜; And
Heating and maintaining a third temperature of 1350-1550 ° C to melt the dried product,
The heating in step (e) is performed at a temperature of 1250 to 1500 ° C,
In the step (f), the mold is maintained at a temperature of 400 to 600 ° C for molding into an ingot shape,
Wherein the heat treatment for crystallization in step (g) is performed at a temperature of 620 to 780 占 폚.

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