JPH0293033A - Dental palladium alloy - Google Patents

Abstract

PURPOSE:To improve the bonding strength of the title alloy with earthenware material and its strength by specifying cobalt, tin, gallium, indium and palladium. CONSTITUTION:The dental palladium alloy is formed with the compsn. constituted of, by weight, 3 to 7% cobalt, 4 to 9% tin, 2 to 6% gallium, 1 to 5% indium and the balance palladium. The above alloy shows excellent function in the bonding with an earthenware material. The alloy has few coloring caused by an oxide film and has no loss of aesthetic properties. The alloy furthermore has sufficient strength and withstands biting pressure at the time of masticating.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a palladium alloy suitable for reinforcing porcelain used as a restoration material for tooth defects.

(Prior Art and Problems to be Solved by the Invention) Porcelain, resin, alloys, etc. have traditionally been used as materials for repairing tooth defects. It is frequently used where it is needed. A mixture of metal oxides such as quartz and alumina is used as the porcelain material, but since it is brittle, it is generally reinforced by baking into an alloy. Such alloys are not only inert in the oral cavity and do not cause any harm to living organisms, but also have sufficient strength to withstand occlusal pressure during mastication and strong bonding strength with porcelain depending on the cooling conditions. It is necessary to have

Dental alloys that have been developed to date, especially alloys for porcelain baking, can be roughly divided into high-strength precious metal alloys containing 90% by weight or more of gold and platinum, and high-strength precious metal alloys containing gold and platinum. A low-carat precious metal alloy in which most of the platinum is replaced with silver and/or palladium, a silver-palladium alloy that contains no gold or platinum and has silver and palladium as its main components, and a silver-palladium alloy that contains nickel and chromium as its main components and contains no precious metal elements. There are four types of non-precious metal alloys that do not contain

Among these alloys, high-strength precious metal alloys have good affinity with living organisms (and bond strongly with porcelain), but due to the recent rise in gold and platinum prices, they have become expensive and
Since the main component is gold, the hardness is low (therefore, it is difficult to obtain enough strength to withstand the occlusal pressure during mastication).

Next, low-carat precious metal alloys and silver-palladium alloys have insufficient strength due to their low content of gold and platinum, and the silver, which is a main component, turns into silver oxide during firing of the porcelain. This has the disadvantage that the most important feature of porcelain, its aesthetics, is lost due to the yellowing of the porcelain.

In addition, non-noble metal alloys are the lowest in cost among the four types of alloys and have sufficient strength, but their bonding strength with porcelain is significantly inferior to that of noble metal alloys, and their main components, such as nickel and chromium, are May cause harm to living organisms.

On the other hand, in order to simultaneously improve the drawbacks of these alloys, recently, palladium is the main component, and expensive gold and platinum, silver that yellows porcelain, and nickel and chromium that may be harmful to living bodies have been completely removed. Palladium-free alloys have been proposed.

For example, Japanese Patent Application Laid-open No. 186437/1986 discloses that nickel (N1) and copper (Cu) are contained in a small amount (both 5 to 15% of one kind).
Gallium (Ga) 2-10%, Kermanium (Ge) 0
-1 to 3%, low content of tin (Sn) and indium (In) (both species 0.01 to 5%, calcium (Ca) 0
．． 001-0.7%, Molybde:/(Mo) 0.
001 to 1.2% by weight, the balance being palladium (Pd);
The basic components are 0 to 5 weight % indium, 0 to 10 weight % tin, 0605 to 0.2 weight % aluminum, and 15 to 0.50 weight % rhenium. Fine-grained palladium-based dental alloys for metal-welded porcelain restorative materials have been proposed, with the sum of all components being 100%.

Although these alloys have sufficient strength, there is still room for further improvement in workability, especially elongation. Furthermore, since it contains copper and 8 to 10% by weight of cobalt, there is room for improvement in coloring the oxide film formed during firing of the porcelain.

In addition, as alloys with high elongation (and good workability), palladium, antimony,
Indium, tin.

In a palladium alloy for dental porcelain baking in which other elements are added to a base alloy consisting of iron, the weight mixing ratio of the base material is 50 to 90% palladium and 1 to 25% antimony.
, indium 0.5-15%, tin 0.5-15%, iron 0.1-5%, and the other additive elements mentioned above and their blended weight ratios are molybdenum 0.05-5% and silver 0.01%. ~5
%, cobalt 0.01-1%, nickel 0.01-5%
, silicon 0.01-1%.

Aluminum 0.01-5%, Iridium 0.01-1
%, ruthenium 0.01 to 1%, and a palladium alloy for dental porcelain baking has been proposed in which at least one of these additive elements is added to the above base alloy. However, since this alloy contains antimony as an essential component,
The adhesion between the oxide film formed during porcelain firing and the alloy tends to decrease, and there is room for improvement in the bonding strength between the alloy and the porcelain. Furthermore, since the color of the oxide film is very dark, further improvement is required in terms of the surface aesthetics of the colored porcelain.

(Means for Solving the Problems) The present inventors have developed a palladium alloy that improves the physical properties of the alloy described above, and that the color of the oxide film formed on the alloy surface does not have an adverse effect on the porcelain. - I have been conducting extensive research on this topic. As a result, an alloy that uses palladium as a base material and contains specific amounts of cobalt, tin, gallium, and indium can form a good oxide film with little coloring during porcelain firing, and has sufficient strength. It was discovered that it has a strong bonding strength with porcelain materials.
The present invention has now been completed.

That is, the present invention contains 3 to 7% by weight of cobalt.

4-9% by weight of tin, 2-6% by weight of gallium.

This is a dental palladium alloy characterized by comprising 1 to 5% by weight of indium and the balance being palladium.

Each component of the palladium alloy of the present invention will be explained in detail below.

One component that makes up the palladium alloy of the present invention is cobalt. Cobalt is an element necessary to form a cobalt oxide film on the alloy surface that firmly bonds with the porcelain, and also has the effect of improving the strength of the palladium alloy. The cobalt content is 3 to 7% by weight in the alloy.
It is preferable to select it so that When the content of cobalt is less than 3% by weight, it is difficult to form a good film with little cobalt oxide coloration, resulting in not only a decrease in strength and elongation but also a decrease in bonding strength with the porcelain. On the other hand, if it exceeds 71% by weight, the elongation of the alloy 1 will be reduced, the thickness of the oxide film will increase, coloring will increase, and it will easily peel off from the alloy. The amount of cobalt may be within the above range, but since an oxide film is easily formed by normal firing, K is
Special! /c is most preferably selected from the range of 4 to 6% by weight.

Another component of the palladium alloy of the present invention is tin. The tin is an element necessary to lighten the color of the film made of cobalt oxide and add K so that the aesthetics of the porcelain are not impaired. Further, it is preferable that the tin content in one alloy be selected to be 4 to 9% by weight, and the most preferable range is 5 to 8% by weight. If the tin content is less than 4% by weight, the above functions will not be exhibited, while if it exceeds 9% by weight, the strength and elongation of the alloy will decrease.

Yet another component of the palladium alloy of the present invention is gallium. The gallium is an element necessary for improving the castability of the alloy and further improving the strength of the alloy.

The content of gallium in the alloy is selected to be 2 to 6% by weight, preferably 4 to 5% by weight.

If the content of gallium is less than 2% by weight, the above-mentioned functions will not be exhibited and the elongation will also decrease. on the other hand,
If it exceeds 6% by weight, not only will the alloy become brittle and its strength and elongation will decrease, but the formation of a film made of cobalt oxide will be hindered, and the bonding strength between the palladium alloy and the porcelain will decrease. Additionally, coloration due to gallium increases.

Yet another component of the palladium alloy of the present invention is indium. The indium is an element necessary to improve the adhesion between the cobalt oxide film and the alloy,
It also functions to improve the strength of palladium alloys. The content of indium in the alloy is 1 to 5% by weight,
Preferably, it is selected to be 2 to 4% by weight. If the content of indium is less than 1% by weight, the above functions will not be exhibited, while if it exceeds 5% by weight, the alloy will become brittle and the elongation will be significantly reduced.

The balance of each of the above components of the palladium alloy of the present invention is palladium. The palladium is inert in the oral cavity and has good affinity with living organisms. Also.

It has good castability and workability, and when combined with the specific elements mentioned above, it can achieve high strength and elongation, as well as strong bonding strength with porcelain.

The method for producing a palladium alloy according to the present invention is not limited to a particular schedule. Typical manufacturing methods include cobalt, tin, and gallium.

Indium and palladium each as a single substance.

Alternatively, the raw material may include a master alloy etc. that is pre-alloyed with two or more selected from these element groups,
Examples include a method of alloying these by a known melting method, regardless of whether in vacuum, inert gas, or air. Examples of such melting methods include arc melting, high frequency melting, and furnace melting. In general, a large quantity, moderate melting point, and relatively inactive raw material is dissolved in the melting process, followed by the addition of small amounts or active raw materials.
The method is preferred. Moreover, two or more types of raw materials may be added at the same time, and furthermore, all raw materials may be welded at the same time. Alternatively, it may be produced by a powder metallurgy method in which powders of individual elements or raw material powders including mother alloy powders are mixed and then fired and sintered.

(Effects) The palladium alloy of the present invention exhibits excellent functionality in bonding with porcelain. That is, it not only exhibits a strong bonding force with the porcelain baked on its surface, but also has little coloring due to the oxide film, so the aesthetics of the porcelain is not impaired.

Furthermore, it has sufficient strength to withstand occlusal pressure during mastication. Moreover, since the palladium alloy of the present invention has palladium as its main component, it is inert when placed in the oral cavity and does not cause any harm to living organisms (it also has excellent castability and processability. Based on the manufacturing method, the palladium alloy of the present invention can be manufactured at low cost and has the economic advantage of being easily available to users.

The alloy of the present invention, which has the excellent characteristics described above, is applicable not only to porcelain baking alloys but also to other dental prosthetic materials, such as cast crowns and bridge dentures.

It can also be used for applications such as denture bases. Furthermore, as mentioned above, it can be used as a biomaterial for artificial bones, implant materials, etc. because it is inactive in vivo and has high strength.

Examples are shown below to further specifically explain the present invention, but the present invention is not limited to these Examples.

(Example) Examples 1 to 7. Comparative Examples 1 to 15 Metals were added to the composition shown in Table 1, and the composition I
After melting DOIi in a high frequency vacuum melting furnace, it was forged and hot rolled into a plate shape with a thickness of 2 mm. Then add this to 10
It was cut into a shape of mX 10+mX2txm. The palladium alloy piece thus obtained was cast into a shape of 10 x 10 m x 1 by the lost wax method, and was subjected to the following oxidation weight gain test, porcelain aesthetic test, castability test, and hardness measurement test. It was a piece. In addition, the palladium alloy pieces were formed into cylinders of φ2sw + This was used as a test piece for measurement and a test piece for measuring bond strength with porcelain.

The contents of each test are as follows.

(1) Oxidation weight increase test After polishing the surfaces of the two test pieces cast as described above to a mirror-like finish, the weight of each test piece was measured using a new weighing balance manufactured by Long Needle Scale Co., Ltd. It was measured using Next, one test piece was heated in the air at 1000°C for 5 minutes, and the other test piece was heated in the air at 1000°C for 20 minutes to form an oxide film on the alloy surface. After heating, the weight of each test piece was measured again, and the difference from the weight of the heated seedling was determined, and this was taken as the oxidation weight gain. Note that the unit of oxidation weight gain was W/ffl.

The results are also shown in Table 1.

(2) Aesthetics Test of Porcelain After the surface of the specimen was mirror-finished, it was heat-treated in the atmosphere at 980° C. for 5 minutes to form an oxide film on the surface. Next, an opaque porcelain (VMK68.511, A2) manufactured by VITA of West Germany, which had been mixed with water to form a slurry, was uniformly formed on the entire surface of the specimen, and after drying,
Placed in an electric furnace at 00℃ and heated at 5℃ per minute up to 980℃ in vacuum.
The opaque porcelain and the specimen were fired at elevated temperatures. After cooling to room temperature, Dentin porcelain manufactured by VITA (VMK6B, 5
41, A2) and enamel porcelain (VMK68.55
8. A2) was baked. After cooling to room temperature again, it was determined whether the color of the porcelain matched the color of the VITA shade guide. The results are also shown in Table 1.

Note that O in the table indicates that the results matched, and X indicates that there was no match.

(3) Castability test Roughness or cavities on the surface of the test piece were visually confirmed.

The results are also shown in Table 1. Note that 0 in the table indicates that no roughness or blowholes were generated, and X indicates that they were generated.

(4) Hardness measurement The hardness of the alloy was measured by polishing the surface of the test piece to a mirror-like surface and using a micro Vickers hardness meter manufactured by Matsuzawa Seiki @).
The surface hardness was measured according to ISZ, 2244, and this was taken as the hardness of the test piece. In addition, the load for hardness measurement was 5o
oy, the holding time was 20 seconds. The results are shown in Table 1.

(5) Measurement of tensile strength and elongation The tensile strength and elongation of the test piece were determined by conducting a tensile test according to JISZ 2241 using a tensile tester manufactured by Toyo Baldwin. The tensile speed in the measurement was 5 cm per minute, and the distance between the supporting points of the test piece was 20 cm.
It was a day. The results are also shown in Table 1.

(6) Measurement of thermal expansion coefficient The thermal expansion coefficient of the test piece is measured by the difference in thermal expansion between the test piece and quartz from 150°C to 450°C using a small constant force thermal dilatometer manufactured by Rigaku Denki Co., Ltd.

It was determined by measuring the so-called differential thermal expansion. Note that the temperature increase rate was 5° C. per minute.

The results are also shown in Table 1.

←) Measurement of bonding strength with porcelain The surface of a cylindrical test piece with a diameter of 3 cm and a length of 50 m cast as described above was polished to a mirror finish, and then heated in the atmosphere at 980°C for 5 minutes to perform the test. An oxide film was formed on one surface. Next, opaque porcelain manufactured by VITA (VMK6
8.511, A2) was uniformly constructed so that the thickness was 0.3 m. After drying the porcelain, the test piece was
Placed in an electric furnace at 00℃ and heated at 5℃ per minute up to 980℃ in vacuum.
The opaque porcelain and the test piece were baked at elevated temperatures.

After cooling to room temperature, Dentin porcelain manufactured by VITA (VMK
68,541, A2) was baked to a thickness of 3 cm.

After cooling to room temperature again, the porcelain was fixed, and a test piece was pulled out from the porcelain using a tensile testing machine manufactured by Toyo Baldwin. The average shear stress at this time was taken as the bonding strength between the porcelain and the test piece.

The results are also shown in Table 1.

Claims (1)

[Claims] 1. A dental palladium alloy comprising 3 to 7% by weight of cobalt, 4 to 9% by weight of tin, 2 to 6% by weight of gallium, 1 to 5% by weight of indium, and the balance consisting of palladium.