GB2038359A - Dental Restorations Using Castings of Non-precious Metals - Google Patents
Dental Restorations Using Castings of Non-precious Metals Download PDFInfo
- Publication number
- GB2038359A GB2038359A GB7940130A GB7940130A GB2038359A GB 2038359 A GB2038359 A GB 2038359A GB 7940130 A GB7940130 A GB 7940130A GB 7940130 A GB7940130 A GB 7940130A GB 2038359 A GB2038359 A GB 2038359A
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- GB
- United Kingdom
- Prior art keywords
- percent
- alloy
- alloys
- dental
- nickel
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
- C22C19/051—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
- C22C19/055—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 20% but less than 30%
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K6/00—Preparations for dentistry
- A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
- A61K6/84—Preparations for artificial teeth, for filling teeth or for capping teeth comprising metals or alloys
- A61K6/842—Rare earth metals
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- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Oral & Maxillofacial Surgery (AREA)
- Plastic & Reconstructive Surgery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Engineering & Computer Science (AREA)
- Epidemiology (AREA)
- Metallurgy (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Dental Preparations (AREA)
- Dental Prosthetics (AREA)
Abstract
A dental restoration comprises a porcelain-covered body of a non- precious metal alloy which includes 58-68% nickel, 18-23% chromium, 6-10% molybdenum, 0.01 to 5% of at least one rare-earth element, 1 to 4% columbium plus tantalum, up to 2% iron, and lesser quantities of carbon, aluminum, titanium, silicon and manganese. The alloy is resistant to corrosion by mouth fluids, is easy to finish and polish, and is closely matched to the thermal-expansion properties of commercially available dental porcelains. The alloy does not contaminate alloy-melting crucibles, exhibits excellent bonding characteristics to dental porcelains, is easy to melt and cast, and has sufficient ductibility to enable margin burnishing of dental-restoration castings of the alloy.
Description
SPECIFICATION
Dental Restorations Using Castings of Non-Precious Metals
Background of the Invention
Dental restorations such as crowns or artificial teeth have traditionally been made by firing porcelain on a cast body of precious metal such as an alloy of gold. The physical properties of these precious alloys are well understood in dentistry, and the alloys bond properly with porcelain and are compatible for use in the mouth. Gold alloys are easy to melt and cast, are sufficiently ductile to permit burnishing of casting margins in the finishing of dental restorations, and can be polished to a high luster to resist plaque formation. Alloys of precious metals, however are relatively heavy, and have increased in cost to such an extent that substitute materials have been sought in recent years.
It is now known that certain stainless alloys of non-precious metals can be used in dentistry, and examples of specific nickel alloys and processing techniques are set forth in United States Patents 3,716,41 8, 3,727,299, 3,749,570 and 3,761,728, the disclosures of these patents being incorporated herein by reference. These nickel alloys have a higher modulus of elasticity than that of precious metal alloys, contributing to better sag resistance of the ceramo-metal structure after repeated firings in a furnace.
The higher strength of nickel alloys enables use of thinner castings which minimize reduction of the natural tooth structure in preparation for installation of the restoration. Nickel-alloy restorations are also light in weight and low in thermal conductivity, and these features provide greater comfort to a patient with a sensitive or deeply involved tooth. These alloys bond satisfactorily to porcelain, and further have the important economic advantage of being significantly lower in cast than gold or other precious metal alloys.
There are various shortcomings of known nickel alloys. For example, these alloys are difficult to finish and polish, thereby requiring more dental laboratory time as compared to precious-metal alloys.
Bond strengths of nickel alloys to dental porcelains are sensitive to the necessary repeated firings in laboratory manipulation and preparation, and this factor can affect clinical performance of the porcelain and nickel-alloy system. It is desirable, therefore, for a nickel alloy to have a high porcelain-metai bond strength to be compatible with the laboratory processing involved in making a restoration. Another problem is that slags of known nickel alloys tend to adhere to clay crucibles used to melt the alloy prior to casting. It takes time and effort to grind or chip off these tenacious slags to avoid possible contamination of other alloys during subsequent casting.
It is believed that these and other problems arise from the use in known alloys of elements such as beryllium, tin, silicon, gallium and boron which are added for improved melting and casting performance. In contrast to precious-alloy ingots which melt into a pool with little or no slag, prior-art nickel-alloy ingots tend to form into an individual molten mass covered by a thick slag when melted by a torch. This problem is at least partially controlled by use of the aforementioned elements, but not without incurring other problems.
For example, beryllium poses a health risk if not carefully handled during alloy processing. Alloys containing significant amount of siiicon and gallium tend to be brittle, and have an as-cast elongation of only about 2% due to the formation of intermetallic compounds. Alloys of this type must be heat treated at 1 8000F for about 30 minutes, foilowed by slow cooling in air, to provide sufficient ductility for margin burnishing, and the increased labor cost arising from this processing tends to cancel the reduced cost of a non-precious alloy. Some other alloys exhibit satisfactory ductility (over 5% elongation as cast), but microscopic carbides and intermetallics in the alloy result in more difficult and time-consuming shaping and polishing as compared to castings of precious alloys.
The new alloy of this invention overcomes these disadvantages of known nickel alloys, while maintaining the advantages of these materials as described above.
Summary of the Invention
This invention relates to the use of non-precious alloys characterized by high nickel-chrome content, and by the inclusion of molybdenum, columbium plus tantalum, at least one element selected from the rare-earth family, and other lesser components to provide thermal-expansion characteristics closely matched to commercially available dental porcelains, excellent bonding characteristics to these porcelains, good ductility, and easy shaping and polishing characteristics.
Description of the Preferred Embodiment
The non-precious dental alloy of this invention has the following elemental components (percentages are by weight):
Element Acceptable Range ( /OJ Nickel 58-68 Chromium 18-23 Molybdenum i 610 Columbium plus tantalum 0.1-4 Element Acceptable Range {%) One or more rare-earth elements 0.01-5 Iron 0.20-2 Silicon 0.01-0.5 Manganese 0.01-0.4 Titanium 0.01--0.2 Aluminum 0.01-1.0 Carbon 0.01-0.1 The reiatively high chromium content of the alloy, and the use of molybdenum, provide satisfactory corrosion resistance when the alloy is exposed to mouth fluids. The ranges specified for other elemental components are important to insure proper formation of carbide in the alloy (tantalum, columbium, titanium and chromium), for precipitation of the gamma-prime phase (aluminum and titanium), and for solid-solution hardening (molybdenum), these factors all contributing to strength and desired ductility of the final cast alloy. Nickel, chromium and molybdenum are the primary determinants of the thermal-expansion properties of the alloy, though the other components play some role in this characteristic.One or more rare-earth elements (defined as those elements with atomic numbers from 57 through 71 in the periodic chart of elements) and the use of aluminum, contribute to the ease of shaping and polishing the alloy, and provide good melting and casting characteristics.
Beryllium and tin are avoided in formulating the alloy.
The components are alloyed by induction melting under argon, and rare-earth elements are the last addition to the melt. The molten alloy is cast into smell slugs or pellets for convenient remelting when the alloy is subsequently cast into a dental prosthesis.
Conventional techniques are used to make a finished dental restoration with the alloy. A ceramic mold is prepared using the usual lost-wax or burnout-plastic methods. The alloy is then melted (a torch fed with propane at 10 psi and oxygen at 20 psi is used to achieve a 2360--24500F melting range of the alloy) and poured in the mold which is mounted in a centrifugal casting machine. After cooling, the mold is broken away and the casting is cleaned, trimmed, polished and finished in preparation for application of porcelain by the usual firing techniques.
Polishing of the alloy is done with conventional equipment such as a Shofu Brownie and Greenie rubber wheel. The casting is brought to a high luster with an Abbott-Robinson brush (used with polishing compound) and Black's felt wheels impregnated with tin oxide.
The alloys of this invention are particularly weil matched to the thermal properties of commercially available dental porcelains such as distributed by Vita Zahnfabrik under the trademark
VMK-68, distributed by Densply International, Inc. under the trademark Biobond and those distributed by Ceramco Division of Johnson 8 Johnson. These above-named dental porcelains generally form a strong bond to the metal alloy casting of the present invention.
The alloys are also useful in making removable dental appliances such as orthodontic retainers.
The reiative softness of the alloys avoids surface damage to natural teeth over which the appliance is fitted, and the alloys are sufficiently ductile to permit hand shaping for interim or final alignment of the appliance. Utility of the invention is thus not limited to appliances on which porcelain is fired.
Strength, elongation and modulus of elasticity are tested by using an Instron tensile instrument.
Vickers hardness is obtained by testing specimens of the alloy with a microhardness tester with diamond indenter. Thermai expansion coefficients are measured with a dilatometer. These tests and instruments are well known to those skilled in the art.
Typical properties of the alloy of this invention as cast are as follows:
Ultimate tensile strength 75,000 psi
Yield strength (0.2% offset) 54,000 psi
Modulus of elasticity 27x 106 psi
Elongation 8 percent
Vickers hardness 200
Thermal expansion coefficient 14x 10-6 C-' The following examples further illustrate the invention and some of the tests which have been
made in evaluating the invention, and are not intended to be limiting. The figures shown are element
percentages by weight.
Example 1 Example 2 Example 3
Nickel 63.06 60.54 62.80
Chromium 21.60 20.74 21.76
Molybdenum 8.40 8.06 8.45
Dysprosium 1.00 5.00 0
Neodymium O 0 1.00
Example 1 Example 2 Example 3
Columbium plus Tantalum 3.80 3.64 3.85
Iron 1.25 1.20 1.25
Silicon 0.35 0.33 0.34
Manganese 0.28 0.27 0.27
Aluminum 0.10 0.10 0.12
Titanium 0.10 0.07 0.10
Carbon 0.06 0.05 0.06
Alloys of Examples 1 through 3 melt similarly to precious alloys, and form only very thin layers of oxide which cover the molten alloy pool. These alloys are easy to shape and to polish, and exhibit good ductility for burnishing the margins of castings.
Example 4 Example 5 Example 6
Nickel 60.62 62.37 64.18
Chromium 21.12 20.87 21.22
Molybdenum 8.12 8.26 8.34
Samarium 5.00 0 0
Praseodymium 0 3.00 0
Gadolinium O 0 0.50
Columbian plus Tantalum 3.11 3.42 3.71
Iron 1.23 1.24 1.20
Silicon 0.32 0.32 0.30
Manganese 0.25 0.28 0.29
Aluminum 0.10 0.11 0.13
Titanium 0.08 0.07 0.09
Carbon 0.05 0.06 0.04
Alloys of these examples are melted easily and are ductile. These alloys are not shaped and polished as easily as alloys of Examples 1 through 3.
Example 7 Example 8 Example 9
Nickel 60.01 62.99 62.46
Chromium 21.00 21.60 21.63
Molybdenum 8.20 8.40 8.40
Cerium 2.50 0.50 0.50
Lanthanum 1.50 0.50 0.50
Neodymium 0.70 0 0
Praseodymium 0.30 0 0
Tin O 0 0.60
Columbium plus Tantalum 3.72 3.80 3.80
Iron 1.23 1.25 1.25
Silicon 0.32 0.35 0.35
Manganese 0.26 0.28 0.28
Aluminum 0.12 0.17 0.07
Titanium 0.09 0.10 0.10
Carbon 0.05 0.06 0.06
Alloys of Example 7 through 9 are ductile. Alloys of Examples 7 and 8 are very easy to shape and polish. The alloy of Example 9 which contains tin is difficult to shape and polish. Alloys of Example 7 through 9 when melted form a molten mass covered by a somewhat thicker oxide as compared to.
alloys of Example 1 through 3.
Claims (6)
1. A non-precious metal base for a dental restoration, comprising:
a body of a stainless metal alloy configured for intra-oral installation, the alloy comprising about:
58 to 68 percent nickel, 18 to 23 percent chromium, 6 to 10 percent molybdenum, 1 to 4 percent columbium plus tantalum, and 0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and dysprosium.
2. A dental restoration, comprising:
a body of stainless metal alloy configured for intra-oral installation, and a porcelain jacket fired on the alloy body, the alloy comprising:
nickel, 58 to 68 percent;
chromium, 18 to 23 percent;
molybdenum, 6 to 10 percent;
columbium plus tantalum, 1 to 4 percent; iron, 0.02 to 2 percent; silicon, 0.01 to 0.5 percent; manganese, 0.01 to 0.4 percent;
titanium, 0.01 to 0.2 percent;
aluminum, 0.01 to 1.0 percent; carbon, 0.01 to 0.1 percent; and
0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and dysprosium.
3. A method for making a dental restoration, comprising: firing a porcelain jacket on a body of non-precious metal alloy, the alloy comprising:
nickel, 58 to 68 percent; chromium, 18 to 23 percent;
molybdenum, 6 to 10 percent;
columbium plus tantalum, 1 to 4 percent; iron, 0.02 to 2 percent; silicon, 0.01 to 0.5 percent; manganese, 0.01 to 0.4 percent;
titanium, 0.01 to 0.2 percent;
aluminum, 0.01 to 1.0 percent; carbon, 0.01 to 0.1 percent; and
0.01 to 5 percent of at least one rare-earth element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, and dysprosium.
4. A method for making a dental restoration substantially as hereinbefore described.
5. A non-precious metal base for a dental restoration substantially as hereinbefore described in any one of the Examples.
6. A dental restoration substantially as hereinbefore described in any one of the Examples.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US05/962,118 US4210447A (en) | 1974-05-01 | 1978-11-20 | Dental restorations using castings of non-precious metals |
Publications (2)
Publication Number | Publication Date |
---|---|
GB2038359A true GB2038359A (en) | 1980-07-23 |
GB2038359B GB2038359B (en) | 1983-05-25 |
Family
ID=25505441
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB7940130A Expired GB2038359B (en) | 1978-11-20 | 1979-11-20 | Dental restorations using castings of nonprecious metals |
Country Status (9)
Country | Link |
---|---|
JP (1) | JPS5573841A (en) |
CA (1) | CA1147988A (en) |
CH (1) | CH633956A5 (en) |
DE (1) | DE2946863A1 (en) |
FR (1) | FR2441380A1 (en) |
GB (1) | GB2038359B (en) |
HK (1) | HK89886A (en) |
IT (1) | IT1120627B (en) |
SE (1) | SE449178B (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4556534A (en) * | 1983-12-20 | 1985-12-03 | Dentsply Research & Development Corp. | Nickel based casting alloy |
US4592890A (en) * | 1983-08-08 | 1986-06-03 | Dentsply Research & Development Corp. | Dental prostheses alloy |
EP0648850A1 (en) * | 1993-09-20 | 1995-04-19 | Mitsubishi Materials Corporation | Nickel-based alloy |
US6103383A (en) * | 1998-01-27 | 2000-08-15 | Jeneric/Pentron Incorporated | High tungsten, silicon-aluminum dental alloy |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1982003007A1 (en) * | 1981-03-03 | 1982-09-16 | Komar Kalmar Jozsef | Cobalt and nickel alloy,in particular for the preparation of dental protheses |
DE3630321A1 (en) * | 1986-09-05 | 1988-03-10 | Thyssen Edelstahlwerke Ag | Material for crowns and bridges to be veneered with dental ceramic |
IT1216774B (en) * | 1987-01-09 | 1990-03-14 | Centro Speriment Metallurg | NON PRECIOUS ALLOY FOR NICKEL-BASED DENTAL PROSTHESES AND CONTAINING CHROME |
JPH01119111A (en) * | 1987-10-30 | 1989-05-11 | Alpine Electron Inc | Display system for audio device |
JP4672433B2 (en) * | 2005-05-17 | 2011-04-20 | 株式会社東芝 | Heat-resistant casting alloy and manufacturing method thereof |
RU2454988C1 (en) * | 2011-01-18 | 2012-07-10 | Федеральное Государственное Унитарное Предприятие "Центральный научно-исследовательский институт черной металлургии им. И.П. Бардина" (ФГУП "ЦНИИчермет им. И.П. Бардина") | High-strength nickel alloy for orthopaedic dentistry |
CN110273085B (en) * | 2019-04-15 | 2022-01-07 | 上海大学 | Gadolinium-rich nickel-based alloy material for reactor spent fuel storage and preparation method thereof |
CN110373573B (en) * | 2019-08-13 | 2021-06-04 | 上海大学 | Gadolinium-rich nickel-tungsten-based alloy material for nuclear shielding and preparation method thereof |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE788719A (en) * | 1971-09-13 | 1973-01-02 | Cabot Corp | NICKEL-BASED ALLOY RESISTANT TO HIGH TEMPERATURES AND THERMALLY STABLE OXIDIZATION |
US3914867A (en) * | 1974-05-23 | 1975-10-28 | Dentsply Res & Dev | Dental alloy |
JPS5129316A (en) * | 1974-09-06 | 1976-03-12 | Nippon Steel Corp | |
US4053308A (en) * | 1974-12-24 | 1977-10-11 | Howmedica, Inc. | Nonprecious alloy for fusion to porcelain |
FR2378869A1 (en) * | 1977-02-01 | 1978-08-25 | Touitou Richard | Nickel-base alloy for use in metalloceramic dental prostheses - providing improved adhesion between the metal and ceramic layers |
-
1979
- 1979-11-16 FR FR7928353A patent/FR2441380A1/en active Granted
- 1979-11-19 SE SE7909578A patent/SE449178B/en not_active IP Right Cessation
- 1979-11-19 IT IT50852/79A patent/IT1120627B/en active
- 1979-11-19 CA CA000340082A patent/CA1147988A/en not_active Expired
- 1979-11-20 CH CH1035979A patent/CH633956A5/en not_active IP Right Cessation
- 1979-11-20 GB GB7940130A patent/GB2038359B/en not_active Expired
- 1979-11-20 JP JP15054379A patent/JPS5573841A/en active Granted
- 1979-11-20 DE DE19792946863 patent/DE2946863A1/en active Granted
-
1986
- 1986-11-20 HK HK898/86A patent/HK89886A/en unknown
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4592890A (en) * | 1983-08-08 | 1986-06-03 | Dentsply Research & Development Corp. | Dental prostheses alloy |
US4556534A (en) * | 1983-12-20 | 1985-12-03 | Dentsply Research & Development Corp. | Nickel based casting alloy |
EP0648850A1 (en) * | 1993-09-20 | 1995-04-19 | Mitsubishi Materials Corporation | Nickel-based alloy |
US5529642A (en) * | 1993-09-20 | 1996-06-25 | Mitsubishi Materials Corporation | Nickel-based alloy with chromium, molybdenum and tantalum |
US6103383A (en) * | 1998-01-27 | 2000-08-15 | Jeneric/Pentron Incorporated | High tungsten, silicon-aluminum dental alloy |
Also Published As
Publication number | Publication date |
---|---|
GB2038359B (en) | 1983-05-25 |
JPS6249340B2 (en) | 1987-10-19 |
IT1120627B (en) | 1986-03-26 |
FR2441380A1 (en) | 1980-06-13 |
IT7950852A0 (en) | 1979-11-19 |
FR2441380B1 (en) | 1982-11-26 |
HK89886A (en) | 1986-11-28 |
SE449178B (en) | 1987-04-13 |
SE7909578L (en) | 1980-05-21 |
CH633956A5 (en) | 1983-01-14 |
JPS5573841A (en) | 1980-06-03 |
DE2946863A1 (en) | 1980-05-29 |
CA1147988A (en) | 1983-06-14 |
DE2946863C2 (en) | 1987-11-19 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |