KR101345339B1 - Ni-cr dental alloys with combined properties of a low melting point and high strength and elongation - Google Patents

Abstract

The present invention relates to a low-melting point nickel-chrome based dental alloy having excellent strength and ductility. More particularly, the present invention relates to a dental alloy, which is prepared by adding an appropriate amount of molybdenum (Mo), aluminum (Al), niobium (Nb), tantalum (Ta), or the like to enhance the yield strength, adding an appropriate amount of boron (B), iron (Fe), niobium (Nb), tantalum (Ta), or the like to improve the elongation, and adding an appropriate amount of boron (B), silicon (Si), niobium (Nb), or the like to lowe the melting point. The alloy of the present invention is harmless to the human body, satisfies the yield strength or elongation, and lowers the melting point, thereby remarkably improving the castability in the dental or molding process in the dental laboratory and thus easily manufacturing dentures. Further, the alloy of the present invention enhances the binding strength with the proclaim material, thereby enhancing the masticatory strength and improving dental esthetics while using teeth for a long time.

Description

Ni-Cr dental alloys with combined properties of a low melting point and high strength and elongation}

The present invention relates to an alloy for dental ceramics, and more particularly, it does not contain beryllium (Be), which is harmless to the human body and satisfies yield strength and elongation, but also has a particularly low melting point, such as pores and moldings in dental laboratories. A low melting Ni-Cr based dental alloy excellent in castability and excellent in strength and ductility providing ease in producing dentures.

Generally, metals have excellent mechanical properties such as tensile strength and compressive strength, but they have the disadvantage that they can not obtain the natural tooth color due to the unique color of the metal, and they also cause corrosion. Therefore, in order to overcome these disadvantages, we use dental prosthesis alloy which combines excellent mechanical properties and precision of porcelain and metal with excellent aesthetics. Such an alloy is called an alloy for ceramic porcelain.

Because dental alloys are used in the oral cavity where various environmental changes such as temperature, acidity, and pressure change occur, they should first be able to withstand the mating pressure, be free of wear and deformation, be comparable to the hardness and strength of teeth , Should be similar to tooth color. In addition, there should be no corrosion or discoloration in the mouth and no harmfulness to human body. From this point of view, non-precious metal prosthetic alloys for dental porcelain soap satisfying all conditions are nickel (Ni) - chromium (Cr) based ceramics.

However, almost all nickel-chromium (Cr) based alloys which are currently sold globally contain beryllium (Be), which is likely to cause various diseases due to toxicity. The reason for adding beryllium (Be) to the nickel (Ni) - chromium (Cr) based alloy is that harmful to the human body, beryllium (Be) is added not only to lower the melting point of the alloy and improve the casting composition, This is because the thickness of the oxide layer is thin, thereby enhancing the bonding strength with the porcelain as well as excellent esthetics. As the toxicity of beryllium (Be) became known, its use was restricted and a commercial alloy containing no beryllium (Be) was developed. However, bonding strength with porcelain is lower than that of beryllium alloy.

On the other hand, it is known that the bonding strength between an alloy and a porcelain depends on the coefficient of thermal expansion of the metal and the thickness, composition, and roughness of the oxide layer formed on the surface of the metal. In the alloy containing no beryllium (Be) For the improvement, it is a key technology to control the characteristics of the oxide layer by appropriately designing the composition of the alloy.

Beryllium (Be) is an alkaline earth metal belonging to the second group of the periodic table and is used as a moderator and a reflector of a reactor, and is known as a harmful substance. Therefore, when exposed to high concentrations of dust for a short period of time or at low concentrations of dust for a long time, it causes acute contact dermatitis. In case of continuous exposure for more than one year, chronic lung disease, acute interstitial pneumonia, chronic beryllium poisoning . As a result, the Korea Food & Drug Administration revised the maximum allowable content of beryllium (Be) from 2% to 0.02% through the revision of the 'Medical Device Standard Partial Amendment Notice' in July 2008, and the manufacture of dental alloys containing beryllium (Be) I have ordered an import ban.

Further, in the case of the nickel (Ni) -crome (Cr) based alloy for porcelain porcelain, it replaces human teeth unlike an alloy used for other purposes, For yield strength or elongation, appropriate standards should be met. The alloys for ceramics are exposed to the fatigue load caused by the chewing motion and their lifespan depends heavily on the mechanical properties such as yield strength and elongation.

On the other hand, if the elongation rate of the alloy for porcelain forming part is small, there is a possibility that the dent casted by the dentist may be broken. If the yield strength is too high, it is difficult for the dentist to postpone the denture. Therefore, there is a demand for a ceramic material alloy having a high elongation and an appropriate yield strength for the life of the teeth and ease of dental cavities.

However, in the case of the conventional nickel (Ni) based alloy, the yield strength, the elongation and the elastic modulus meet the above-mentioned appropriate reference value. However, beryllium (Be) . Recently, a cobalt (Co) based alloy mainly composed of cobalt (Co) has been produced in order to overcome the disadvantage of a nickel (Ni) based alloy containing harmful beryllium (Be) The product is dissolved even if a part of cobalt (Co) system having a low melting point is produced. However, due to the nature of cobalt (Co), a thick oxide film is formed when dissolving. Therefore, it is necessary to perform several polishing operations, There is a case where the bonding strength with the porcelain becomes weak due to the remaining oxide layer due to the work.

An object of the present invention for solving the above problems is not beryllium (Be) is not harmless to the human body but satisfies the yield strength and elongation, etc., but also the melting point is particularly low castability such as pores or molding in the dental laboratories The present invention relates to a low-melting Ni-Cr based dental alloy having excellent strength and ductility providing excellent ease in manufacturing dentures.

Low-melting Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention for achieving the above object, 22.0 to 27.0% by weight of chromium (Cr) and 3.0 to 5.0% by weight of molybdenum (Mo ), 0.4 to 0.6 wt% aluminum (Al), 0.4 to 0.6 wt% silicon (Si), 0.4 to 0.6 wt% iron (Fe), 0.15 wt% or less boron (B), Niobium (Nb) of 5.0 to 9.0 wt% is included, and the rest is characterized by consisting of nickel (Ni).

Further, the low-melting Ni-Cr dental alloy having excellent strength and ductility according to the present invention includes 22.0 to 27.0 wt% chromium (Cr), 3.0 to 5.0 wt% molybdenum (Mo), and 0.4 to 0.6 wt%. % Aluminum (Al), 0.4 to 0.6 wt% silicon (Si), 0.4 to 0.6 wt% iron (Fe), 0.15 wt% or less boron (B), and 5.0 to 9.0 wt% niobium (Nb), 2.0 wt% or less of tantalum (Ta), and the remainder is made of nickel (Ni).

As described above, in the low-melting Ni-Cr dental alloy having excellent strength and ductility according to the present invention, yielding without using beryllium (Be) in an alloy containing nickel (Ni) and chromium (Cr) as a main component Molybdenum (Mo), silicon (Si), aluminum (Al), niobium (Nb), tantalum (Ta), etc. are added in order to improve the strength, and boron (B), iron (Fe), and niobium ( Nb), tantalum (Ta) and the like are added in an appropriate amount, and in order to lower the melting point, boron (B), silicon (Si), niobium (Nb) and the like are added to make a dental alloy.

Therefore, it is not only harmless to the human body but also satisfies the yield strength, elongation, and the like, and has a particularly low melting point, which is excellent in castability such as pores and molding in the dental laboratories.

In addition, by improving the bonding force with the porcelain has the advantage that can be used for a longer time to improve the chewing strength and aesthetics of the tooth.

1 is a mechanical property evaluation result table according to an embodiment of the low-melting point Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention.
Figure 2 is a thermal analysis graph showing the melting point according to one embodiment of the low melting point Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention.
Figure 3 is a graph showing the bonding strength according to one embodiment of the low melting point Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the low-melting point Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention.

1 is a mechanical property evaluation result table according to an embodiment of a low melting point Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention, Figure 2 is a low melting point excellent in strength and ductility according to the present invention Thermal analysis graph showing the melting point according to an embodiment of the Ni-Cr-based dental alloy is shown, Figure 3 of the low-melting point Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention In accordance with one embodiment a graph showing the bond strength is shown.

The effect of each component element in the low-melting Ni-Cr-based dental alloy excellent in strength and ductility according to the present invention has a very complicated effect, so if the content exceeds or falls below each specific range, the effect is rather adverse. do. Therefore, in the present invention, nickel (Ni) as a main component, chromium (Cr), molybdenum (Mo), aluminum (Al), silicon (Si), iron (Fe), boron (B), niobium (Nb), tantalum (Ta) ) Is added in an appropriate amount, preferably 22.0 to 27.0% by weight of chromium (Cr), 3.0 to 5.0% by weight of molybdenum (Mo), 0.4 to 0.6% by weight of aluminum (Al), 0.4 to 0.6% by weight of silicon (Si), 0.4 to 0.6 wt% of iron (Fe), 0.15 wt% or less of boron (B), and 5.0 to 9.0 wt% of niobium (Nb), and the remainder of the percentage is mixed so as to consist of nickel (Ni).

In addition, 2.0 wt% or less of tantalum (Ta) may be further included in the alloy to be mixed.

In the above mixture, nickel (Ni) is a material having excellent resistance to corrosion and discoloration resistance, which significantly increases the tensile strength and yield strength of the alloy and is biologically stable by the combination with chromium (Cr), and chromium (Cr) And the stability can be maintained in the oral environment by the passivation mechanism by the formation of dense oxide film. Therefore, nickel (Ni) is preferably mixed in the range of 55 to 69% by weight and chromium (Cr) is mixed in the range of 22 to 27% by weight in order to improve corrosion resistance.

And, molybdenum (Mo) has the advantage of improving the coefficient of thermal expansion and corrosion resistance and increase the strength of the alloy, aluminum (Al) to make up the alloy to compensate for the weak strength of the light, high strength and durable properties Since the alloy with silicon (Si) has the advantage of excellent moldability and corrosion resistance, silicon (Si) has the advantage of good castability because it has good strength and lower the melting point. Therefore, in order to obtain the above characteristics, molybdenum (Mo) is limited to the range of 3.0 to 5.0 wt%, aluminum (Al) is limited to the range of 0.4 to 0.6 wt%, and silicon (Si) is 0.4 to 0.6 wt% It is desirable to.

In addition, iron (Fe) not only improves the elongation, but also improves the properties of the oxide layer to improve the bonding strength with the porcelain, and boron (B) improves the melting point and castability of the alloy and strengthens the grain boundary. Niobium (Nb) is an element with excellent biocompatibility. It is an alloy with nickel (Ni), which not only lowers the melting point of nickel (Ni) but also forms a solid solution or precipitates in nickel (Ni). By increasing the strength and ductility, tantalum (Ta) is a malleable and ductile, bio-friendly element with an alloy with nickel (Ni) has the advantage of improving the tensile strength. Therefore, in order to obtain the characteristics described above, iron (Fe) is mixed in the range of 0.4 to 0.6% by weight, boron (B) is limited to 0.15% by weight or less, niobium (Nb) is 5.0 to 9.0 weight % And tantalum (Ta) is preferably mixed together in a proportion of up to 2.0% by weight.

Meanwhile, in order to obtain a mechanical characteristic evaluation result table as shown in FIG. 1, a specimen should first be manufactured.

Cr Mo Al Si Fe B Nb Ta Ni G11 24.0 4.0 0.5 0.5 0.5 0.1 5.0 2.0 63.4

24.0 wt% chromium (Cr), 4.0 wt% molybdenum (Mo), 0.5 wt% aluminum (Al), 0.5 wt% silicon (Si), 0.5 wt% iron (Fe), 0.1 wt% boron (B), niobium ( Nb) 5.0% by weight, tantalum (Ta) 2.0% by weight, and the rest 63.4% by weight of nickel (Ni) to charge the above elements in the crucible in a vacuum or argon (Ar) atmosphere and the temperature of 1500 ℃ to 1550 ℃ After melt | dissolving at high temperature, it inject | pours into a mold and naturally cools for about 1 to 2 hours, and the mechanical characteristic evaluation result value as shown in FIG. 1 can be obtained.

Cr Mo Al Si Fe B Nb Ta Ni G12 22.0 3.0 0.5 0.5 0.5 0.1 8.0 65.4

22.0 wt% chromium (Cr), molybdenum (Mo) slightly reduced 3.0 wt%, aluminum (Al) 0.5 wt%, silicon (Si) 0.5 wt%, iron (Fe) 0.5 wt%, boron (B) 0.1 wt% By increasing the ratio of niobium (Nb) to 8.0% by weight, without adding tantalum (Ta), and preparing the specimen in the same manner as in the experiment for obtaining G11 by preparing 65.4% by weight of nickel (Ni) with the remainder of FIG. 1 Mechanical property evaluation results as in the above can be obtained.

Cr Mo Al Si Fe B Nb Ta Ni G13 22.0 3.0 0.5 0.5 0.5 0.1 9.0 64.4

22.0 wt% chromium (Cr), 3.0 wt% molybdenum (Mo), 0.5 wt% aluminum (Al), 0.5 wt% silicon (Si), 0.5 wt% iron (Fe), 0.1 wt% boron (B), niobium ( The weight of Nb) was slightly increased to 9.0% by weight, and the remainder was prepared in 64.4% by weight of nickel (Ni) to prepare a specimen in the same manner as in the experiment for obtaining G11. You can get it.

Cr Mo Al Si Fe B Nb Ta Ni G14 22.0 4.0 0.5 0.5 0.5 0.1 8.0 64.4

22.0 wt% chromium (Cr), slightly increased molybdenum (Mo) 4.0 wt%, 0.5 wt% aluminum (Al), 0.5 wt% silicon (Si), 0.5 wt% iron (Fe), 0.1 wt% boron (B) Niobium (Nb) is slightly reduced to 8.0 wt%, and the remainder is mixed with 64.4 wt% with nickel (Ni) to prepare the specimen in the same way as the experiment to obtain the G11 mechanical properties as shown in FIG. Evaluation results can be obtained.

Cr Mo Al Si Fe B Nb Ta Ni G15 22.0 5.0 0.5 0.5 0.5 0.1 8.0 63.4

22.0 wt% chromium (Cr), molybdenum (Mo) slightly increased to 5.0 wt%, aluminum (Al) 0.5 wt%, silicon (Si) 0.5 wt%, iron (Fe) 0.5 wt%, boron (B) 0.1 The mechanical properties evaluation results as shown in FIG. 1 can be obtained by preparing the specimen by the same method as the experiment for obtaining G11 by preparing the wt%, 8.0 wt% of niobium (Nb), and 63.4 wt% of the remainder with nickel (Ni). .

Cr Mo Al Si Fe B Nb Ta Ni G16 22.0 5.0 0.5 0.5 0.5 0.1 8.0 2.0 61.4

22.0 wt% chromium (Cr), 5.0 wt% molybdenum (Mo), 0.5 wt% aluminum (Al), 0.5 wt% silicon (Si), 0.5 wt% iron (Fe), 0.1 wt% boron (B), niobium ( Nb) added 2.0% by weight of tantalum (Ta) to 8.0% by weight, and preparing the specimen in the same manner as in the experiment to obtain the G11 by preparing the remaining 61.4% by weight of nickel (Ni) as shown in FIG. Characteristic evaluation result can be obtained.

The results of mechanical properties of G are compared with those of Supranium (A), Nobel (B), Verabond 2V (C), and T3 (D) which are commercially available alloy products in FIG. A thermal analysis graph, shown at 3 and showing melting points, is shown in FIG. 2 compared to T3 (D) above.

This shows that the combination of strength and elongation is superior to that of Supranium (A), Nobel (B), Verabond 2V (C), and T3 (D), which are commercially available alloy products, and the bond strength is higher than that of (A). It can be seen that the level is similar to (C). In particular, the melting point is lowered to facilitate the dissolution of oxygen or gas torch in the dental laboratories, the experimental value of G16 compared to T3 (D) which is a product containing beryllium (Be) harmful to the human body in the present invention It can be seen that the results showed almost the same melting point as the Be-free component composition of (Be).

The scope of the present invention is not limited to the above-described embodiments, and many other modifications based on the present invention will be possible to those skilled in the art within the scope of the present invention.

Claims (2)

22.0 to 27.0 weight percent chromium (Cr), 3.0 to 5.0 weight percent molybdenum (Mo), 0.4 to 0.6 weight percent aluminum (Al), 0.4 to 0.6 weight percent silicon (Si), 0.4 to 0.6 weight percent 0.6% by weight of iron (Fe), 0.15% by weight or less of boron (B), and 5.0 to 9.0% by weight of niobium (Nb), the remainder is composed of nickel (Ni) and Low-melting Ni-Cr dental alloy with excellent ductility. 22.0 to 27.0 weight percent chromium (Cr), 3.0 to 5.0 weight percent molybdenum (Mo), 0.4 to 0.6 weight percent aluminum (Al), 0.4 to 0.6 weight percent silicon (Si), 0.4 to 0.6 weight percent 0.6 wt% iron (Fe), 0.15 wt% or less boron (B), 5.0 to 9.0 wt% niobium (Nb), 2.0 wt% or less tantalum (Ta), and the rest nickel (Ni) Low-melting Ni-Cr-based dental alloy excellent in strength and ductility, characterized in that consisting of.

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