EP0101457A1 - Admix dental alloy and amalgam - Google Patents
Admix dental alloy and amalgamInfo
- Publication number
- EP0101457A1 EP0101457A1 EP83900602A EP83900602A EP0101457A1 EP 0101457 A1 EP0101457 A1 EP 0101457A1 EP 83900602 A EP83900602 A EP 83900602A EP 83900602 A EP83900602 A EP 83900602A EP 0101457 A1 EP0101457 A1 EP 0101457A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- alloy
- weight
- tin
- silver
- atomic percentage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C7/00—Alloys based on mercury
-
- 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
- A61K6/847—Amalgams
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C30/00—Alloys containing less than 50% by weight of each constituent
- C22C30/04—Alloys containing less than 50% by weight of each constituent containing tin or lead
Definitions
- This invention relates in general to a dental composition and dental amalgam suitable for use in repairing carious tooth structure. More specifically the invention relates to a .substantially uniform admixture of two powdered alloys in the form of spheroids and irregularly-shaped or cut particles which when amalgamated with mercury exhibit improved handling characteristics.
- U.S. Patent 3,985,558 teaches an improved dental alloy having a relatively low concentration of silver and a critical atomic ratio of silver plus copper to tin which exhibits enhanced mechanical properties and handling characteristics as compared to conventional high silver alloys.
- the alloy is also more economical to use than conventional alloys which require higher silver concentrations.
- Prior art admix compositions generally combine two different alloy compositions for the respective spherical and irregularly- shaped components. This runs the risk that segregation of individual components may result and lead to inconsistent properti in the final amalgamated alloy.
- the alloys Prior to amalgamation, the alloys are annealed by techniques well known in the art to control the work time of the final alloy. The alloys are also cleaned by chemically treating with a dilute acid.
- the alloy of the present invention is composed of an admixture of spherical and irregularly-shaped or "cut" particles.
- the alloy powder has a fine particle size (all about -325 mesh) , of both the spherical and irregular particles which allows the alloy to have the smooth carve associated with all spherical alloys, but with a firmer packing and carving consistency characteristic of conventional alloys.
- the particle size range for both components is from submicron to about 50 microns.
- Both of the particle configurations are made to the same composition: About 24 to 45 weight percent silver, 28 to 42 weight percent copper and 29 to 34 weight percent tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin.
- a particularly preferred composition comprises about 41% silver, 28% copper and 31 percent tin.
- the powder admixture must be maintained in a weight ratio of about 65 to 85 percent spherical to 15 to 35 percent irregular in order to obtain the enhanced properties described herein. The benefits of this relationship are quite clear; both of the particle configurations participate heavily in the reaction with mercury during amalgamation, therefore enhancing the consistency of the mix and the homogeneity of the amalgam.
- each particle in the alloy of the present invention contains copper, assures that it is distributed fully throughout the amalgam to alloy with tin to prevent formation of the unwanted gamma-2 (tin-mercury) phase.
- This admix alloy produces an amalgam with a smooth carve, but with the body that can be comfortably worked. The amalgam begins to "body-up” upon condensation, which allows for carving to commence almost immediately, with the resistance to carve
- OMP increasing up until the end of working time which can be controlled typically to vary from about 6 1/2 to 11 minutes.
- the alloy composition used was the preferred composition of 41% silver, 28% copper and 31% tin in a weight ratio of 70% spherical to 30 percent irregular particles.
- the concentration of mercury was 48% by weight and the admix alloy constituted 52 weight percent. Both alloy components were of fine particle size of less than 325 mesh.
- the tests were carried out according to ADA speci ication No. 1 for Dental Amalgams.
- the physical properties of the Alloy of the present invention compare favorably to those of other commercial dental alloys.
- spheroidal as used to describe the shape, configuration or form of the first component in the admixture of the present invention means that the individual particles are spheres or shaped like a spheroid.
- the spherical component may be formed by any technique well known to the dental art.
- it may be prepared by first forming a molten alloy in the above concentration ranges and atomizing said alloy at approximately 2,000°F. Atomization is achieved in a conventional manner as described in U.S. Pat. No. 3,305,356 at column 2, lines 9-50, which is incorporated herein by reference. The alloy is then collected and classified using a 325 mesh sieve. The fraction passing through the sieve is retained as the dental alloy product.
- the term "irregularly-shaped" or “cut” as used to described the configuration or form of the second component means that the individual particles are substantially non-equiaxial and are multi-sided and generally angularly shaped or irregular, and usually with rough or otherwise relatively non-smooth surfaces. Typically they are in the form of what is variously referred to in the art as microcut material, lathe-cut material, platelets or filings. Conventional microcutting, lathe cutting or filing techniques, usually from a cast billet of the alloy, can be employed satisfactorily to obtain the irregularly-shaped particles and are well known to those skilled in the art. The irregular particles used in this invention should all be less than 325 mesh in size.
- the dental composition of this invention be in the form of a particulate mixture of the two alloys when used, and may be supplied in such form when supplied, it should be understood that for distribution purposes the two alloys can be in the form of separate powders which can be mixed together by the ultimate user in the required proportions.
- the two admixed alloys in the required proportions can also be pressed into a tablet, used in a capsule form for convenience, or used in bulk powder dispensers.
- the spherical to irregular weight ratio is preferably about 4 to 1; for use in capsule form the preferred ratio is about 7 to 3.
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Oral & Maxillofacial Surgery (AREA)
- Plastic & Reconstructive Surgery (AREA)
- Epidemiology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Dental Preparations (AREA)
- Powder Metallurgy (AREA)
Abstract
Composition indiquée pour l'amalgamation avec du mercure pour former un amalgame dentaire, comprenant un mélange sensiblement uniforme d'une proportion importante en poids du premier alliage sous forme de particules sphéroïdales se composant essentiellement de 24 à 45 % en poids environ d'argent, 28 à 42 % en poids de cuivre et 29 à 34 % en poids d'étain, et où le pourcentage atomique de la quantité totale d'argent plus le cuivre est environ trois fois supérieur au pourcentage atomique de l'étain; une proportion inférieure en poids d'un deuxième alliage sous forme de particules de formes irrégulières possède la même composition que le premier alliage.Composition indicated for amalgamation with mercury to form a dental amalgam, comprising a substantially uniform mixture of a large proportion by weight of the first alloy in the form of spheroidal particles essentially consisting of 24 to 45% by weight approximately of silver, 28 to 42% by weight of copper and 29 to 34% by weight of tin, and where the atomic percentage of the total amount of silver plus copper is approximately three times greater than the atomic percentage of tin; a lower proportion by weight of a second alloy in the form of particles of irregular shapes has the same composition as the first alloy.
Description
ADMIX DENTAL ALLOY AND AMALGAM
BACKGROUND OF THE INVENTION
This invention relates in general to a dental composition and dental amalgam suitable for use in repairing carious tooth structure. More specifically the invention relates to a .substantially uniform admixture of two powdered alloys in the form of spheroids and irregularly-shaped or cut particles which when amalgamated with mercury exhibit improved handling characteristics.
U.S. Patent 3,985,558 teaches an improved dental alloy having a relatively low concentration of silver and a critical atomic ratio of silver plus copper to tin which exhibits enhanced mechanical properties and handling characteristics as compared to conventional high silver alloys. The alloy is also more economical to use than conventional alloys which require higher silver concentrations.
When the above dental alloy is used in the spherical form and not blended with an appreciable concentration of cut or irregularly shaped alloy particles, certain desirable working characteristics such as resistance to condensation or packing within the tooth cavity cannot be attained.
Prior art admix compositions generally combine two different alloy compositions for the respective spherical and irregularly- shaped components. This runs the risk that segregation of individual components may result and lead to inconsistent properti in the final amalgamated alloy.
OBJECTS OF THE INVENTION It is therefore an object of this invention to provide an improved dental alloy suitable for amalgamation with mercury which exhibits outstanding physical and mechanical properties and handli characteristics.
It is another object of this invention to provide a dental amalgam which exhibits outstanding physical and mechanical properties and handling characteristics.
SUMMARY OF THE INVENTION
It has now been discovered that when an alloy of the type taught by U.S. Patent 3,985,558 in the form of a substantially uniform blend of two powdered alloys comprised of spheroids and irregularly- shaped particles, is amalgamated with mercury, the final dental alloy exhibits enhanced handling characteristics. A critical ratio of spherical to irregularly-shaped particles for this alloy ranges from about 65 to 85% spherical to 15 to 35% irregular. The alloy described above is amalgamated by trituration with mercury in a concentration of about 45 to 55 weight percent mercury with the balance of the amalgam comprising the alloy.
Prior to amalgamation, the alloys are annealed by techniques well known in the art to control the work time of the final alloy. The alloys are also cleaned by chemically treating with a dilute acid.
■ OMPI
DETAILED DESCRIPTION OF THE INVENTION The alloy of the present invention is composed of an admixture of spherical and irregularly-shaped or "cut" particles. The alloy powder has a fine particle size (all about -325 mesh) , of both the spherical and irregular particles which allows the alloy to have the smooth carve associated with all spherical alloys, but with a firmer packing and carving consistency characteristic of conventional alloys. The particle size range for both components is from submicron to about 50 microns. Both of the particle configurations are made to the same composition: About 24 to 45 weight percent silver, 28 to 42 weight percent copper and 29 to 34 weight percent tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin. A particularly preferred composition comprises about 41% silver, 28% copper and 31 percent tin. The powder admixture must be maintained in a weight ratio of about 65 to 85 percent spherical to 15 to 35 percent irregular in order to obtain the enhanced properties described herein. The benefits of this relationship are quite clear; both of the particle configurations participate heavily in the reaction with mercury during amalgamation, therefore enhancing the consistency of the mix and the homogeneity of the amalgam. Unlike the alloy of the present invention, many other prior art admixtures because of the different composition of the two components, risk segregation of the individual components which may lead to inconsistencies. The fact that each particle in the alloy of the present invention contains copper, assures that it is distributed fully throughout the amalgam to alloy with tin to prevent formation of the unwanted gamma-2 (tin-mercury) phase. This admix alloy produces an amalgam with a smooth carve, but with the body that can be comfortably worked. The amalgam begins to "body-up" upon condensation, which allows for carving to commence almost immediately, with the resistance to carve
OMP
increasing up until the end of working time which can be controlled typically to vary from about 6 1/2 to 11 minutes.
In the following Table the physical properties for the average of four lots of an amalgamated dental alloy of the present invention are tabulated. The alloy composition used was the preferred composition of 41% silver, 28% copper and 31% tin in a weight ratio of 70% spherical to 30 percent irregular particles. The concentration of mercury was 48% by weight and the admix alloy constituted 52 weight percent. Both alloy components were of fine particle size of less than 325 mesh. The tests were carried out according to ADA speci ication No. 1 for Dental Amalgams.
TABLE
Four Lots
DC (Microns/cm.) -1.80 Tension (psi)
15 min 857
1 hr 2620
24 hr 7870
7 day 8740
Compression (psi)
15 min 8320
1 hr 26000
24 hr 75000
7 day 81300
Creep {%) .067
In addition to providing the advantages described herein, the physical properties of the Alloy of the present invention compare favorably to those of other commercial dental alloys.
The term "spheroidal" as used to describe the shape, configuration or form of the first component in the admixture of the present invention means that the individual particles are spheres or shaped like a spheroid. The spherical component may be formed by any technique well known to the dental art.
For example it may be prepared by first forming a molten alloy in the above concentration ranges and atomizing said alloy at approximately 2,000°F. Atomization is achieved in a conventional manner as described in U.S. Pat. No. 3,305,356 at column 2, lines 9-50, which is incorporated herein by reference. The alloy is then collected and classified using a 325 mesh sieve. The fraction passing through the sieve is retained as the dental alloy product.
The term "irregularly-shaped" or "cut" as used to described the configuration or form of the second component means that the individual particles are substantially non-equiaxial and are multi-sided and generally angularly shaped or irregular, and usually with rough or otherwise relatively non-smooth surfaces. Typically they are in the form of what is variously referred to in the art as microcut material, lathe-cut material, platelets or filings. Conventional microcutting, lathe cutting or filing techniques, usually from a cast billet of the alloy, can be employed satisfactorily to obtain the irregularly-shaped particles and are well known to those skilled in the art. The irregular particles used in this invention should all be less than 325 mesh in size.
While it is essential that the dental composition of this invention be in the form of a particulate mixture of the two alloys when used, and may be supplied in such form when supplied, it should be understood that for distribution purposes the two alloys can be in the form of separate powders which can be mixed together by the ultimate user in the required proportions. Alternatively, the two admixed alloys in the required proportions can also be pressed into a tablet, used in a capsule form for convenience, or used in bulk powder dispensers. When used in tablet form the spherical to irregular weight ratio is preferably about 4 to 1; for use in capsule form the preferred ratio is about 7 to 3.
OMPI
Other modifications and ramifications of the present invention would appear to those skilled in the art upon readin this disclosure. These are also intended to be within the scope of this invention.
Claims
1. A composition suitable for amalgamation with mercury to form a dental amalgam comprising a substantially uniform blend of: a. a major proportion by weight of a first alloy in the form of spheroidal particles having a particle size distribution in the range of about submicron to about 50 microns and consisting essentially of about 24 to 45 weight percent silver, 28 to 42 weight percent copper and 29 to 34 weight percent tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin; and b. a minor proportion by weight of a second alloy in the form of irregularly-shaped particles having a particle size distribution in the range of about submicron to 50 microns and consisting essentially of about 24 to 45 weight percent silver, 28 to 42 weight percent copper and 29 to 34 weight percent tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin.
2. The composition of claim 1 containing about 65% to about 85% by weight of said first alloy and about 15% to about 35% by weight of said second alloy.
3. The composition of claim 1 containing approximately 4 parts by weight of said first alloy and 1 part by weight of said second alloy.
4. The composition of Claim 1 containing approximately 7 parts by weight of said first alloy and 3 parts by weight of said second alloy.
5. The composition of claim 1 wherein said composition contains up to about 2% zinc.
6. The composition of claim 1 amalgamated with about 45 to 55 weight percent of mercury to form a workable dental amalgam.
7. A process for preparing a dental amalgam which comprises triturating the composition of claim 1 with sufficient mercury to form a workable plastic amalgam.
8. A composition suitable for amalgamation with mercury to form a dental amalgam comprising a substantially uniform blend of: a. About 65% to 85% by weight of a first alloy in the form of fine spheroidal particles consisting essentially of about
24 to 45 weight percent silver, 28 to 42 weight percent copper and 29 to 34 weight percent tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin; and b. About 15% to 35% by weight of a second alloy in the form of fine irregularly-shaped particles consisting essentially of about 24 to 45 weight percent silver, 28 to 42 weight percent copper and 29 to 34 weight percent tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin.
9. A composition suitable for amalgamation with mercury to form a dental amalgam comprising a substantially uniform blend of: a. About 70% to 80% by weight of a first alloy in the form of spheroidal particles having a particle size distribution in the range of about submicron to about 50 microns and consisting essentially of about 41% silver, 28% copper and 31% tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin; and b. About 20% to 30% by weight of a second alloy in the form of irregularly-shaped particles having a particle size distribution in the range of about submicron to 50 microns and consisting essentially of about 41% silver, 28% copper and 31% tin, and where the atomic percentage of the total amount of silver plus copper is about 3 times greater than the atomic percentage of tin.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US34989582A | 1982-02-18 | 1982-02-18 | |
| US349895 | 1982-02-18 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0101457A1 true EP0101457A1 (en) | 1984-02-29 |
| EP0101457A4 EP0101457A4 (en) | 1986-04-15 |
Family
ID=23374426
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP19830900602 Withdrawn EP0101457A4 (en) | 1982-02-18 | 1983-01-17 | Admix dental alloy and amalgam. |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0101457A4 (en) |
| JP (1) | JPS59500220A (en) |
| AU (1) | AU557405B2 (en) |
| CA (1) | CA1222401A (en) |
| IT (1) | IT1164867B (en) |
| WO (1) | WO1983002959A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA844462B (en) * | 1983-06-27 | 1985-01-30 | Dentsply Int Inc | Dental composition mixture |
| US5490870A (en) * | 1993-10-28 | 1996-02-13 | Special Metals Corporation | Amalgamable composition and method of production |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2377191A1 (en) * | 1977-01-17 | 1978-08-11 | Engelhard Min & Chem | CORROSION-RESISTANT DENTAL ALLOY WITH IMPROVED HANDLING CHARACTERISTICS |
| EP0033628A2 (en) * | 1980-01-31 | 1981-08-12 | Macrodent S.A. | A product to be used in dental amalgams |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3305356A (en) * | 1963-08-30 | 1967-02-21 | William V Youdelis | Dental amalgam |
| US3841860A (en) * | 1973-07-11 | 1974-10-15 | Dentsply Res & Dev | Dental alloy |
| US3963484A (en) * | 1974-08-20 | 1976-06-15 | Sarkar Nikhil K | Dental amalgam alloys |
| US4039329A (en) * | 1975-02-20 | 1977-08-02 | Youdelis William V | Dental powder composite and amalgam |
| US3985558A (en) * | 1975-03-28 | 1976-10-12 | Sybron Corporation | Dental alloy and amalgam |
| US3954457A (en) * | 1975-04-28 | 1976-05-04 | Gary Maurice Weikel | Dental amalgam |
| US3980472A (en) * | 1975-07-16 | 1976-09-14 | Special Metals Corporation | Dental amalgam |
| US3997329A (en) * | 1975-12-29 | 1976-12-14 | Engelhard Minerals & Chemicals Corporation | Dental composition |
| US3997330A (en) * | 1975-12-29 | 1976-12-14 | Engelhard Minerals & Chemicals Corporation | Dental amalgams |
| US3997328A (en) * | 1975-12-29 | 1976-12-14 | Engelhard Minerals & Chemicals Corporation | Dental amalgams |
| US3997327A (en) * | 1975-12-29 | 1976-12-14 | Engelhard Minerals & Chemicals Corporation | Dental composition |
| US4030918A (en) * | 1976-05-27 | 1977-06-21 | Johnson & Johnson | Indium containing dental alloy powder |
| US4080199A (en) * | 1976-05-27 | 1978-03-21 | Johnson & Johnson | Lathe cut dental alloy powder |
| US4311526A (en) * | 1979-07-30 | 1982-01-19 | Pei Sung | γ2 - Free, low cost amalgam alloy powders |
| US4255192A (en) * | 1979-12-17 | 1981-03-10 | Pennwalt Corporation | Homogenous bonding of dispersed phase alloy |
-
1983
- 1983-01-17 JP JP83500648A patent/JPS59500220A/en active Pending
- 1983-01-17 EP EP19830900602 patent/EP0101457A4/en not_active Withdrawn
- 1983-01-17 WO PCT/US1983/000063 patent/WO1983002959A1/en not_active Application Discontinuation
- 1983-01-17 AU AU11583/83A patent/AU557405B2/en not_active Ceased
- 1983-02-03 CA CA000420837A patent/CA1222401A/en not_active Expired
- 1983-02-10 IT IT47691/83A patent/IT1164867B/en active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2377191A1 (en) * | 1977-01-17 | 1978-08-11 | Engelhard Min & Chem | CORROSION-RESISTANT DENTAL ALLOY WITH IMPROVED HANDLING CHARACTERISTICS |
| EP0033628A2 (en) * | 1980-01-31 | 1981-08-12 | Macrodent S.A. | A product to be used in dental amalgams |
Non-Patent Citations (1)
| Title |
|---|
| See also references of WO8302959A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0101457A4 (en) | 1986-04-15 |
| JPS59500220A (en) | 1984-02-16 |
| IT8347691A0 (en) | 1983-02-10 |
| IT1164867B (en) | 1987-04-15 |
| WO1983002959A1 (en) | 1983-09-01 |
| CA1222401A (en) | 1987-06-02 |
| AU1158383A (en) | 1983-09-08 |
| AU557405B2 (en) | 1986-12-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
| AK | Designated contracting states |
Designated state(s): AT BE CH DE FR GB LI LU NL SE |
|
| 17P | Request for examination filed |
Effective date: 19840206 |
|
| A4 | Supplementary search report drawn up and despatched |
Effective date: 19860415 |
|
| 17Q | First examination report despatched |
Effective date: 19870604 |
|
| RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: KERR MANUFACTURING COMPANY (A DELAWARE CORPORATION |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
| 18D | Application deemed to be withdrawn |
Effective date: 19880929 |
|
| RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: CUTLER, GARY S. Inventor name: NELSON, RUSSELL E. |