JPH01283332A - Palladium alloy for dental use - Google Patents

Abstract

PURPOSE:To obtain an excellent Pd alloy for dental use having less coloring at the time of calcining earthenware material and in which a good oxidation film is formed by regulating Pb as a matrix and incorporating specific amounts of Fe, Sn, Ga and In thereto. CONSTITUTION:As an alloy for dental use, particularly as an alloy for baking of earthenware material, a Pd alloy constituted of, by weight, 3-10% Fe, 3-12% Sn, 3-10% Ga, 0.1-10% In and the balance consisting of Pd is used. The Pd alloy for dental use having high bonding strength with earthenware material, in which the color of an oxidation film generated on the surface does not exert adverse influence on the earthenware material, having sufficient strength and elongation and furthermore having excellent castability and workability can be obtd.

Description

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

(Prior Art and Problems to be Solved by the Invention) Conventionally, materials used to repair missing teeth include porcelain, resin,
Alloys and the like are used, and among these, porcelain is frequently used where the color of natural teeth is required. A mixture of metal oxides such as quartz and alumina is used as the porcelain, but since it is brittle, it is generally reinforced by baking into an alloy. Such alloys are
In addition to being inert in the oral cavity and causing no harm to living organisms, it must also have enough strength to withstand occlusal pressure during mastication and a strong bonding force with the porcelain material depending on the intended use.

Dental alloys that have been developed so far, especially alloys for porcelain baking, can be roughly divided into high-strength rat precious metal alloys containing a total of 90% gold and platinum; gold contained in high-strength rat precious metal alloys; and low-carat precious metal alloys in which most of the platinum is replaced with silver and/or IP radium; silver-silver-radium alloys containing no gold or platinum but mainly composed of silver and radium; and nickel- and chromium-based alloys. There are four types of non-noble metal alloys that do not contain any precious metal elements.

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

Second, low-carat precious metal alloys and silver-i4-carat alloys are lower in cost than high-strength precious metal alloys due to their lower content of gold and platinum, but their strength is insufficient and their constituent components Silver turns into silver oxide during firing of the porcelain and causes the porcelain to yellow, which has the disadvantage that the most important feature of the porcelain, its aesthetics, is impaired.

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 are nickel and chromium. may cause harm to living organisms.

In order to simultaneously improve the drawbacks of these alloys, we have recently developed a new alloy that uses palladium as its main component and does not contain any expensive gold or platinum, silver that yellows porcelain, or nickel or chromium that may be harmful to living organisms. Nogradium alloys have been proposed.

For example, in JP-A-61-186437, Ni and C
At least 5 to 15 qb of one type of u, 2 to 10 qb of Ga, Ge
At least one of O, 1-3qb, 8n and In 0.0
1-5%, Ca 0.001-0.7%, Mo 0.
A dental alloy consisting of 0.001% to 1.2%, the balance being Pd,
In addition, Japanese Patent Application Laid-open No. 59-28545 discloses that substantially about 35 to 85% palladium, 0 to 12% copper, 5 to 15% by weight,
% gallium, 0-50% gold, 0-5% aluminum, 0-13% cobalt, and 0.1-0.5% ruthenium or rhenium (however, the sum of these components is 100%) A radium-based dental alloy consisting of
Furthermore, Japanese Patent Application Laid-Open No. 61-60843 describes a palladium alloy for baking dental porcelain in which other elements are added to the base alloy consisting of 4 radium, antimony, indium, tin, and iron. Ratio is palladium 50-9
0%, antimony 1-25%, 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 0.5-15%.
05-5%.

0.01-5% silver, 0.01-1% nickel, 0.01-5% silicon, 0.01-5% aluminum, 0.01-1% iridium, 0.01% ruthenium. 01 to 1%, and a radium alloy for dental porcelain baking has been proposed in which at least one of these additive elements is added to the base alloy.

These alloys are cheaper than precious metal alloys containing gold;
The strength is also sufficient. However, since the main ingredients are copper and antimony, the oxide film formed during firing of the porcelain becomes very dark in color, which impairs the aesthetics of the porcelain. Furthermore, when the firing time becomes longer, the thickness of the oxide film increases, the adhesion between the oxide film and the alloy decreases, and there is also the drawback that the alloy may peel off from the porcelain.

(Means for Solving the Problems) The present inventors have conducted intensive research on a dental tsucladium alloy that improves the above-mentioned drawbacks and in which the color of the oxide film formed on the alloy surface does not have an adverse effect on the porcelain. I've been repeating it.

As a result, palladium was used as the base material, and a specific amount of iron was added to it.
An alloy containing tin, gallium, and indium can form a good oxide film with little coloring during firing of porcelain, and has sufficient strength and elongation as well as strong bonding strength with porcelain. This finding led to the completion of the present invention.

That is, the present invention contains 3-10% by weight of iron, 3-12% by weight of tin, 3-10% by weight of gallium, and 0.1-1% by weight of indium.
This is a dental palladium alloy characterized by comprising 0% by weight and the balance being 70% by weight.

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

The ceradium alloy of the present invention has many excellent properties for use in porcelain baking.

One component that makes up the alloy of the present invention is iron.

The iron is an element necessary to form an iron oxide film on the surface of the alloy that firmly bonds with the porcelain, and also has the effect of improving the strength of the alloy. The iron content is preferably selected to be 3 to 10% by weight in the alloy. If the iron content is less than 3 parts by weight, it will be difficult to form a good film with little iron oxide coloring, and the bonding strength with the porcelain will decrease, while if it exceeds 10 parts by weight, the strength of the alloy will be reduced. Not only does this decrease the oxide film, but it also increases the thickness of the oxide film, making it easier to peel off from the alloy. The amount of iron may be within the above range, but in order to easily form an oxide film by normal firing, it is most suitable if it is selected from the range of 4 to 8% N.

Another component of the alloy of the present invention is tin. The tin is an element necessary to lighten the color of the film made of iron oxide so that the aesthetics of the porcelain is not impaired.
It exhibits properties that improve the adhesion between crushed iron oxide and alloy. The tin is preferably selected in an amount of 3-12% by weight in the alloy, most preferably in a range of 4-9% by weight.

If the tin content is less than 3% by weight, the above functions will not be exhibited, while if it exceeds 12% by weight, the strength of the alloy will decrease.
, Yet another component of the 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 is 3 to 10% by weight in the alloy, and the content of gallium is 4 to 8% by weight.
Selected to be a weight clerk. If the gallium content is less than 3% by weight, the above functions will not be exhibited;
If it exceeds 10% by weight, it not only embrittles the alloy, but also prevents the formation of a film made of iron oxide, resulting in significant discoloration.

Yet another component of the alloy of the present invention is indium. Indium is an element necessary to reduce the difference in thermal expansion coefficient between the alloy and the porcelain and to prevent the porcelain from peeling off from the alloy during firing of the porcelain.

The content of indium in the alloy is preferably selected to be 01 to 101 to 10% by weight or 0.5 to 8% by weight. If the indium content is less than 0.1ffiJ1%, the above function will not be exhibited, while if it exceeds 10% by weight, the alloy will become brittle.

The balance of each of the above components of the alloy of the present invention is enriched with isoradium. This isoradium is inactive in the oral cavity and has good affinity with living organisms. In addition, it has good castability and workability, and when combined with the above-mentioned elements, high strength and strong bonding force with porcelain can be obtained.

The method for producing the alloy of the present invention is not particularly limited. For example, iron, tin, gallium, indium, and palladium are used as raw materials, either singly or together with a master alloy made by pre-alloying two or more of these elements, and these are heated in a vacuum under an inert gas. During,
Regardless of whether it is in the atmosphere or not, alloying is generally performed by a known melting method.

Examples of such melting methods include arc melting, high frequency melting, and furnace melting. In general, it is preferable to melt the raw materials in a large amount, have an appropriate melting point, and relatively inactive starting with the raw materials, and then sequentially add small amounts or active raw materials. Moreover, two or more kinds of raw materials may be added at the same time, and furthermore, all the raw materials may be melted 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 alloy of the present invention exhibits excellent functionality when used in any porcelain. That is, it not only has a strong bonding force with the porcelain material, but also does not impair the aesthetics of the porcelain material. Furthermore, it has sufficient strength against occlusal pressure during mastication. Moreover,
Since the alloy of the present invention is mainly composed of AI radium, it is inert in the oral cavity and does not cause any harm to living organisms.
It also has excellent castability and workability. Furthermore, the alloy of the present invention has the economic advantage of being able to be manufactured at low cost and easily available to users based on its manufacturing method.

The alloy of the present invention, which has the excellent characteristics described above, can be used not only as an alloy for porcelain baking, but also in other dental prosthetic materials, such as cast crowns, bridge dentures, and 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) The alloy with the composition shown in Table 1 is about 50I! After melting in a high frequency vacuum melting furnace, it was forged and hot rolled to a thickness of 2n, and then cut into a 101+1lIX 10N1RX 2 dragon shape. Next, the alloy obtained as described above is
The pieces were cast in the shape of i) 10IIX 10 dragons by the lost wax method, and the pieces were used as test pieces for oxidation weight gain tests, porcelain aesthetic tests, castability tests, and hardness measurements. In addition, the above alloy was cast using a similar casting method to obtain a diameter of 2iIII,
A cylinder with a length of 50 mm and a cylinder with a diameter of 4 mm and a length of 20 mm were formed, and the former was used as a test piece for measuring tensile strength and elongation.
The latter was used as a test piece for measuring the coefficient of thermal expansion. Further, by the same casting method, it was molded into a 25 m x 6 x 1 positive shape, and used as a test piece for measuring the bonding force with porcelain. The contents of each test are as follows.

(1) Oxidation weight gain test After polishing the surfaces of the two test pieces cast as described above to a mirror finish, the weight of each test piece was weighed using a rupture scale manufactured by Long Needle Scale Co., Ltd. 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 before heating was determined, and this was determined as the weight gain by oxidation. The unit of oxidation weight gain was ~/cm''. The results are shown in Table 1.

(2) After mirror-finishing the surface of the porcelain aesthetic test specimen, it was heated in the atmosphere at 980°C for 5 minutes to form an oxide film on the alloy surface.Next, water was added to make it mud-like. Opaque porcelain manufactured by VITA of West Germany (VMK 68, 511).

A2) was uniformly formed on the entire alloy surface, and after drying, it was placed in an electric furnace at 700°C and heated at 980'C in vacuum.
The over-covered porcelain and the test piece were fired by increasing the temperature at a rate of 5° C. per minute until the temperature reached 5°C. After cooling to room temperature, VITA's Moffin porcelain (VMK 68, 541, A2) and enamel porcelain (VMK 68, 558, A2) were applied to the opaque porcelain by the same firing method as above. After cooling to room temperature again, it was determined whether the color of the porcelain matched the color of the shade guide on the back of VITA.The results are shown in Table 11C.In addition, ○ in the table indicates a match. , × indicates no match.

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

The results are shown in Table 1. In the table, ◯ indicates that no roughness or blowholes were generated, and × 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 finish, using a Micro Vickers hardness meter manufactured by Matsuzawa Seiki Co., Ltd.
The surface hardness was measured according to JIS Z 2244, and this was taken as the hardness of the alloy. In addition, the load in hardness measurement is 5
0011, and 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 alloy were determined by conducting a tensile test according to JIS Z 2241 using a tensile testing machine manufactured by Toyo Baldwin. In addition, the tensile speed in the measurement was 5III+ per minute, and the distance between the supporting points of the test piece was 20 mm. The results are shown in Table 1.

(6) Measurement of thermal expansion coefficient The thermal expansion coefficient of the alloy is measured using a micro constant force thermal dilatometer manufactured by Rigaku Denki Co., Ltd. The difference in thermal expansion between the alloy and quartz from 150°C to 450°C, the so-called differential It was determined by measuring thermal expansion. Note that the temperature increase rate was 5° C. per minute. The results are shown in Table 1.

(7) Measurement of bond strength with porcelain After polishing the surfaces of two test pieces cast as described above, measuring 25 mm in length, 6 fl in width, and 1 mm in thickness, to a mirror finish,
The alloy was heated in the air at 980° C. for 5 minutes to form an oxide film on the alloy surface. Next, water was added to a portion of one test piece measuring 4 mm long and 6 mm wide from the end to form a slurry.

511, A2), and this thickness is 0.1 V
It was sandwiched between the other test pieces so that In addition, 2
The test specimens were stacked horizontally in opposite directions. After drying the porcelain, the stacked test pieces were heated to 800°C.
The porcelain and test piece were baked in an electric furnace at a temperature of 980°C at a rate of 5°C per minute in a vacuum. Both test pieces were pulled in opposite directions in the horizontal direction using the aforementioned tensile testing machine to break them, and the average stress at this time was taken as the bonding force between the porcelain and the alloy. The results are shown in Table 1.

Claims (1)

[Claims] Iron 3-10% by weight, Tin 3-12% by weight, Gallium 3-3%
A dental palladium alloy comprising 10% by weight of indium, 0.1 to 10% by weight of indium, and the balance consisting of palladium.