JPS642179B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The disclosed technology belongs to the field of alloy composition technology for baking porcelain in dental healing treatment. <Summary of the gist> The present invention is an alloy for baking dental porcelain, which is a base alloy consisting of a predetermined composition of palladium, gold, antimony, and indium, in which other trace elements are blended. This invention relates to a palladium-gold alloy for baking dental porcelain, and in particular, the composition of the base alloy is as follows: palladium 30 to 75%, gold 10 to 60%, antimony 1 to 25%, in terms of material elements and weight ratios. It is a composition alloy with a compounding ratio of 0.5 to 15% indium, and other trace elements mixed with this are gallium in weight ratio.
0.01 to 10% tin, 0.01 to 10% tin, 0.1 to 5% iron, and 0.01 to 1% iridium, and at least one of these trace elements is blended into the alloy with the above composition ratio. This invention relates to a palladium-gold alloy for baking dental porcelain. <Prior art> As is well known, there are various healing methods and means in dental treatment, but various technical techniques are available for attaching dentures to replace missing teeth such as broken teeth. It has been used since ancient times. In recent years, seed dentures have been developed with a focus on physical aspects that deal with functions during use, chemical aspects that deal with changes in properties during use, and aesthetic aspects that greatly affect the feel and psychology during use. Three aspects have come to be regarded as important as constraints for healing and techniques, and in order to basically satisfy these three aspects, metal bodies mainly made of alloys have been developed since ancient times. A technique is used to bake porcelain on the surface and integrate it, and the alloy with this porcelain baked is used as a so-called porcelain baking alloy. Therefore, the basic conditions of the porcelain baking alloy that restrict the function of dentures include, of course, the inherent mechanical properties of the porcelain in order to match the properties of the porcelain to which it is bonded. Although it is hard, the downside of brittleness is compensated as much as possible by the alloy metal, and there are inherently strong physicochemical bonding conditions that aim to integrate the two. The elastic modulus of the alloy is high with respect to the occlusal force applied during occlusal chewing that is frequently repeated in the oral cavity, and the thermal expansion coefficients of the porcelain and the alloy match as much as possible during baking, and furthermore, The physicochemical properties of both during firing are such that the melting point of the alloy is higher than the firing temperature of the porcelain, and furthermore, the bonding strength between the metal molecules of the porcelain and the alloy after firing is strong. This is a necessary condition. The conventional alloys for porcelain baking that have been developed so far can be roughly divided into noble metal alloys containing gold as the main component, palladium-silver alloys containing palladium and silver as the main component, and nickel and silver alloys. It is classified as a non-precious metal alloy whose main components are chromium and cobalt. <Problem to be solved by the invention> Therefore, in the above-mentioned conventional porcelain baking alloy,
Precious metal alloys mainly composed of gold have a strong bond with porcelain because the coefficient of thermal expansion of gold is almost the same as that of porcelain, and have good compatibility with porcelain. Although it has the positive side of being widely used because it is welcomed for its satisfaction, it naturally has the disadvantage of being expensive due to its main component being gold. Also, because it is mainly composed of gold, its hardness value is low, and although it has good compatibility with porcelain, it is soft as an alloy for porcelain baking.
It has the disadvantage of not being able to withstand the occlusal pressure that is applied during chewing, and there is a risk that the bonded porcelain may peel off from the alloy due to repeated feeding, and it also has poor resistance to high temperatures. The problem is that the alloy is deformed during the porcelain firing process and does not meet the basic requirements due to its weakness. On the other hand, palladium-silver alloys, which are mainly composed of palladium and silver, have the advantage of being cheaper in terms of cost and having a higher hardness value because they do not contain gold compared to noble metal alloys, but they still contain less gold. In addition to the disadvantage that the ideal hardness value is insufficient to withstand the occlusal pressure during eating, the porcelain may be colored during firing, resulting in large damage to the porcelain baking alloy. It had the disadvantage of losing its characteristic aesthetics, and was not as good as noble metal alloys whose main component was gold. In addition, non-precious metal alloys are the cheapest in terms of cost and are superior in terms of hardness, high-temperature strength, etc., but they have poor technical castability in dental healing treatments, and they also have high As a result, the porcelain becomes colored during firing, making it less aesthetically pleasing as an oral cavity material.Furthermore, it has the disadvantage that it does not have sufficient bonding strength with the porcelain. For certain reasons, it was still inferior to the above-mentioned noble metal alloys containing gold as a main component. <Objective of the Invention> The object of the present invention is to solve the problems of noble metal alloys whose main component is gold, which are inherently superior as alloys for porcelain baking based on the above-mentioned prior art, and to , improved mechanical properties such as coefficient of thermal expansion and strength, and improved physicochemical properties such as high temperature strength characteristics, castability, and melting point, and also improved bondability with porcelain. An excellent base alloy that satisfies almost all of the properties required as an alloy for porcelain baking and is low cost, as well as a selective blend of these, makes it an excellent alloy for porcelain baking. By selecting at least one other trace element that further increases The purpose of this invention is to provide a palladium-gold alloy for firing porcelain. <Means/effects for solving the problems> In order to solve the problems mentioned above, the structure of the present invention, which is based on the scope of the above-mentioned claims, is as follows:
As a palladium-gold alloy for porcelain firing used in dental healing and treatment, it is basically made to match the coefficient of thermal expansion with the porcelain, and when fired with the porcelain, its melting point is higher than the firing temperature of the porcelain. The weight ratio of palladium, which is necessary to improve the bonding and compatibility of porcelain and prevent it from discoloring or corroding in the oral cavity, should be 30 to 75%, and for gold, the weight ratio should be 30 to 75%. Basically, its thermal expansion coefficient matches that of porcelain, and therefore it is necessary to strengthen the bond between porcelain and alloy and improve mechanical properties, and its weight ratio is 10 to 60%. Antimony not only improves compatibility with porcelain materials, but also improves castability, so it does not cause coloring of porcelain materials and does not reduce the aesthetically healthy color. The weight ratio is 1 to 25%, and further,
Regarding indium, an oxide film is formed on the alloy surface to strengthen the bond between the porcelain and the alloy, and the weight ratio is also adjusted to improve castability and compatibility.
0.5 to 15%, and increases the bonding force with the porcelain material in order to selectively improve the properties of the base alloy with these compositions, and improves the gingiva in the oral cavity. Reproducing an aesthetically healthy color in the area,
The weight ratio of gallium to other blended elements is 0.01 to 10 to provide a deoxidizing effect, improve mechanical properties, improve castability, refine crystals, and prevent brittleness of the alloy. %, for tin 0.01-10%, for iron 0.1-5%,
Regarding iridium, it should be 0.01 to 1%, and
This is a technical measure in which at least one of the above elements is selectively blended to improve the properties. <Theoretical Composition Background> Next, we will discuss the qualitative and quantitative theoretical background and experimental conditions for limiting the composition of each component and its weight ratio in the palladium gold alloy for dental porcelain baking of this invention. Explain the reasons for the background. That is, first, to explain the base alloy, palladium is used as a material for dental healing treatment, and is used in combination with porcelain.
It is used to sufficiently ensure compatibility and therefore has a coefficient of thermal expansion equal to that of the porcelain, and is necessary to raise the melting point of the alloy higher than the firing temperature of the porcelain. Furthermore, as mentioned above, it is a basic metal that does not change color or elute in the oral cavity after wearing the denture, and is necessary to ensure sufficient corrosion resistance, and experimentally shows that 30% Experiments have shown that adding more than 75% reduces the effect, and that adding more than 75% causes the melting point to become higher than necessary, which not only deteriorates castability and compatibility, but also worsens the bonding strength with the porcelain. Since this was confirmed, the addition weight ratio was set at 30 to 75%. Next, regarding gold, it is necessary to strengthen the bond between the alloy and porcelain and to improve mechanical properties.
If it is less than 60%, the effect cannot be expected, and if it is added more than 60%, the mechanical properties will deteriorate, making it impossible to withstand occlusal pressure, and increasing costs. This is a range of amounts. Furthermore, antimony is added to improve castability and compatibility with porcelain, and when dentures are worn in the oral cavity, exposed metal parts around the tongue are generally visible. However, it is necessary to aesthetically reproduce a healthy color in the gums of the relevant area, to ensure that the design is not bad, and to prevent discoloration of the porcelain. Therefore, it has been experimentally confirmed that the effect cannot be expected when the amount added is less than 1% by weight, and on the contrary, the good function is lost when the amount added is 25% or more. As for antimony, the weight ratio is limited to 1 to 25% as the optimum addition range. Next, indium improves elasticity against the occlusal pressure applied during chewing in the oral cavity and improves mechanical properties.However, when bonding with porcelain, indium has a suitable thickness on the alloy surface. It acts to form an oxide film to improve castability and compatibility, and experiments have shown that it is necessary to add at least 0.5% by weight to fully exhibit these properties.
On the other hand, it has been confirmed that if more than 15% of indium is added, the high-temperature properties deteriorate and the alloy becomes brittle. Therefore, the addition weight ratio of indium is 0.5%.
The range is limited to ~15%. Regarding other trace elements that are selectively added to the base alloy having these compositions, first of all, gallium has the function of imparting a deoxidizing effect to the alloy, and , not only forms an appropriate oxide film on the alloy surface to strengthen the bond with the porcelain, but also damages the aesthetics of the gingival area of the exposed metal around the tongue when the denture is placed in the oral cavity. It is necessary to effectively reproduce a natural, healthy color, and to prevent the porcelain from becoming colored and deteriorating its aesthetics, and it is only through experiments that these effects can be effectively expected. is within the range of 0.01% and 10%, and 0.01
If it is less than 10%, the above effect cannot be expected;
It has been found that if the weight ratio exceeds 0.01% to 10%, the castability and compatibility deteriorate. In addition, tin is added to improve the mechanical properties against occlusal pressure during mastication, and like palladium, is added to strengthen the bonding force with porcelain, and according to experiments, it is 0.01%. If it is less than 10%, the effect is weak, and if it exceeds 10%, it becomes brittle and undesirable, so the weight ratio is limited to 0.01 to 10%. Next, due to its basic properties, iron improves the mechanical properties, and also forms an appropriate oxide film on the alloy surface to increase the bonding strength with the porcelain. It is an element necessary to increase the carbon content, and experiments have shown that it has almost no desired effect at less than 0.1%, and on the other hand, when added in excess of 5%, it actually impairs its properties. Based on the above results, the optimum weight ratio of addition was determined to be 0.1 to 5%. Finally, iridium is added to increase mechanical properties and make crystals finer, and experiments have shown that a weight ratio of less than 0.01% does not have the desired effect; It has been confirmed that the alloy becomes brittle when the amount of iridium is added is 0.01 to 1%. <Examples> Next, Examples of the present invention are shown in Table 1 below, and are shown together with known alloys for baking porcelain.

[Table] Regarding the samples Nos. 1 to 10 of the comparison examples in Table 1 and the known alloys Nos. 15 and 16, each material element was heated at 1400℃ in a well-known high frequency heating melting furnace. Melt for 30 minutes at melting temperature, t10 x w50
It was cast into a shape of ×l 100 mm, and then rolled into a predetermined shape using a well-known rolling roll. Each sample of the example obtained as described above and the processed material of the known alloy were formed into a desired number of plate-shaped test pieces of t1.0 x w10 x l15 mm by centrifugal casting. A hardness test was conducted. In addition, a rod-shaped test piece with a diameter of 2.0 mm and a length of 50 mm was prepared using the same manufacturing method, and a tensile test and an elongation measurement test were conducted on the rod-shaped test piece. The contents of each test are as follows. 1 Hardness test Using a Microvits hardness tester with a load of 200
g, and the load application time was 30 seconds. 2. Tensile strength test A tensile test piece with a gage length of 20 mm was measured using a Tensilon tensile tester at a tensile speed of 10 mm/min. 3. Elongation measurement test This test was conducted in the same manner as the above tensile strength test. 4 Discoloration observation test After polishing each test piece with No. 400 abrasive paper specified in JIS R 6253, one type of test piece was 37±2
Discoloration was observed after full immersion for 3 days in 0.1% sodium sulfide solution at .degree. For other types of test pieces, the temperature is 37±2℃.
The state of discoloration was observed after being completely immersed for 3 days in a mixed solution of equal amounts of 0.1% sodium sulfide and 1% lactic acid. 5 Porcelain discoloration observation test The presence or absence of discoloration of the porcelain after baking the porcelain on each test piece was observed. The results of each of the above-mentioned tests are shown in Table 2. In the discoloration test results shown in Table 2, the ◯ mark indicates that there was no change at all.

[Table] As can be seen from the test data shown in Table 2,
The palladium-gold alloy for baking dental porcelain materials of this invention has significantly superior hardness and tensile strength compared to conventionally known alloys, is comparable in elongation, and satisfies the special conditions for porcelain materials. We have obtained data to It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments. For example, equivalent elements having the same function and effect as each element of the constituent elements of the above-mentioned claims may be substituted. Various aspects can be adopted, such as being able to be used as <Effects of the Invention> As described above, according to the present invention, basically, in the alloy for baking dental porcelain, the composition of the base alloy and the trace elements added thereto is adjusted to meet the constituent requirements described in the scope of the claims. By limiting the physical, mechanical, and
The excellent effect of providing a palladium-gold alloy that is almost completely satisfactory in terms of chemical properties, hygiene, and aesthetics is achieved. Therefore, even when placed in the oral cavity, the state of bonding with the porcelain material is sufficiently maintained over time.
Moreover, it maintains a sufficient elastic modulus even against mechanically repeated applied forces during occlusion caused by mastication during ingestion, prevents peeling of the porcelain, and also prevents peeling of the porcelain material from the gingiva of the metal exposed area around the tongue side. The excellent effect of being able to reproduce and maintain the aesthetically healthy color of the skin is achieved, and furthermore, the effect of fully satisfying practicality is achieved. In addition, it not only has excellent properties as a tooth, but also has good casting properties and a good deoxidizing effect when placed in the oral cavity.In addition, it has excellent workability and is easy to operate. This has the excellent effect of providing an optimal denture that is easy to remove. Furthermore, since the content of gold can be lower than that of palladium, it has the advantage of being inexpensive and easily available, which is an advantage for dental treatment, and is also advantageous for users and patients. Therefore, the elements added in trace amounts to the base alloy mentioned above can also promote various properties of the base alloy and promote energization, so by selectively adding at least one of these elements, it is possible to improve the properties of dental porcelain. An excellent effect is achieved in that the excellent properties as a palladium-gold alloy can be further improved.

Claims (1)

[Claims] 1. In a palladium-gold alloy for dental porcelain baking, in which other elements are blended with a base alloy consisting of palladium, gold, antimony, and indium, the weight mixing ratio of the material metal of the base alloy is palladium 30 to 75.
%, gold 10-60%, antimony 1-25%, indium 0.5-15%, and the other elements mentioned above and their weight ratios are gallium 0.01-10%, tin 0.01-10%,
A palladium-gold alloy for baking dental porcelain, consisting of 0.1-5% iron, 0.01-1% iridium, and at least one of them.