The document discusses the properties and uses of metals in dentistry. It defines metals and describes their classification into ferrous and non-ferrous groups. Metals solidify through the formation of crystal nuclei that grow into dendritic structures within grains. Smaller grain size improves properties. Dental alloys like cobalt-chromium, titanium, and nickel-chromium are used for implants, crowns, and dentures due to their strength, corrosion resistance, and biocompatibility. Precious metals are also used for restorations.
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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
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Solidification and microstructure of metals/certified fixed orthodontic cours...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Indian Dental Academy: will be one of the most relevant and exciting training
center with best faculty and flexible training programs for dental
professionals who wish to advance in their dental practice,Offers certified
courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry,
Prosthetic Dentistry, Periodontics and General Dentistry.
Introduction
CERAMICS : An inorganic compound with non-metallic prosthesis typically consisting of oxygen and one or more metallic or semi-metallic elements that is formulated to produce the whole part of a ceramic based dental prosthesis. – GPT 7.
The word Ceramic is derived from the Greek word “keramos”, which literally means ‘burnt stuff’, but which has come to mean more specifically a material produced by burning or firing.
1.Introduction
2.Historical perspective
3.Classification
4.Desirable properties
5.Functional mechanical properties
6.Alloys for
A]. All Metal Prosthesis
B]. Resin – Veneered Metal Restoration
7. High noble and noble alloys for Metal- Ceramic Prosthesis
8. Alternative Technologies for fabricating prosthesis
Biological Hazards and precautions – risks of dental laboratory
technician
10. Guidelines for selection and use of base metals for crown and
bridge applications.
11. Partial denture alloys and guidelines for selection
12. Alternatives technologies for fabricating prosthesis
13. Recent advancements
Indian Dental Academy: will be one of the most relevant and exciting training
center with best faculty and flexible training programs for dental
professionals who wish to advance in their dental practice,Offers certified
courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry,
Prosthetic Dentistry, Periodontics and General Dentistry.
Introduction
CERAMICS : An inorganic compound with non-metallic prosthesis typically consisting of oxygen and one or more metallic or semi-metallic elements that is formulated to produce the whole part of a ceramic based dental prosthesis. – GPT 7.
The word Ceramic is derived from the Greek word “keramos”, which literally means ‘burnt stuff’, but which has come to mean more specifically a material produced by burning or firing.
1.Introduction
2.Historical perspective
3.Classification
4.Desirable properties
5.Functional mechanical properties
6.Alloys for
A]. All Metal Prosthesis
B]. Resin – Veneered Metal Restoration
7. High noble and noble alloys for Metal- Ceramic Prosthesis
8. Alternative Technologies for fabricating prosthesis
Biological Hazards and precautions – risks of dental laboratory
technician
10. Guidelines for selection and use of base metals for crown and
bridge applications.
11. Partial denture alloys and guidelines for selection
12. Alternatives technologies for fabricating prosthesis
13. Recent advancements
The process of transformation of a substance from liquid to solid state in which the crystal lattice forms and crystals appear.
•Volume shrinkage or volume contraction
Deeper understanding of process
Virtual variation of operation parameters
Assists in
–Identifying critical process parameters
–Optimizing production process
–Improve productivity
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Metals in prosthodontics/dental crown &bridge course by Indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Metals in prosthodontics/certified fixed orthodontic courses by Indian dental...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Alloys used in dentistry/cosmetic dentistry course by Indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Dental casting alloys /certified fixed orthodontic courses by Indian dental ...Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
Description :
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Indian Dental Academy: will be one of the most relevant and exciting
training center with best faculty and flexible training programs
for dental professionals who wish to advance in their dental
practice,Offers certified courses in Dental
implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic
Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting
training center with best faculty and flexible training programs
for dental professionals who wish to advance in their dental
practice,Offers certified courses in Dental
implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic
Dentistry, Periodontics and General Dentistry.
2. The history of dental restorations and implants dates back to the ancient Egyptians who used bone and bands of gold wire to replace missing teeth. The modern era of dental restorations just began after the turn of the 20th century with the use of number of precious metals as well as some attempts to use zinc,steel,copper and even brass Introduction
4. Metals Definition Any strong and relatively ductile substance that provides electropositive ions to a corrosive environment and that can be polished to a high luster. (G.P.T-8).
5. Metals may be classified into two basic groups :- a) Ferrous b) Non ferrous Classification
6. Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons.
7.
8. In dentistry ,metals represent one of the four major classes of materials used for the reconstruction of decayed, damaged or missing teeth. Although metals are easy to distinguish from ceramics,polymers,and composites,they are not easy to define.
9. Metals are usually inclined to form cations through electron loss. They react with oxygen in the air to form oxides Iron rusts over years, while potassium burns in seconds. Chemical properties
10. The transition metals (such as iron, copper, zinc, and nickel) take much longer to oxidize. Others, like palladium, platinum and gold, do not react with the atmosphere at all.
11. Some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades (like aluminium, some steels, and titanium). The oxides of metals are generally basic (as opposed to those of non-metals, which are acidic.
12. Physical Properties Metals in general have high electric, thermal conductivity, lustre and density, and the ability to be deformed under stress without cleaving.
13. Metals have a high fracture toughness when compared to ceramic, polymers and composites. The fracture toughness of most metals vary between 25 and 60 Mpa compared with a range of 0.75 to 2.5 Mpa.
14. Conductivity One of the chief characteristics of a metal is its ability to conduct heat and electricity. Such energy conduction is associated with the mobility of free electrons present in metals.
15. DensityThe high density of most metals is due to the tightly packed crystal lattice of the metallic structure.
16. Gallium and Mercury elements that are commonly used as alloying elements in dental alloys are liquid at room temperature. Metals are generally resistant to chemical attack but some metals require alloying elements to resist tarnish and corrosion.
17. Metallic bonding is the electromagnetic interaction between delocalized electrons, called conduction electrons, and the metallic nuclei within the metals. Understood as the sharing of "free" electrons among a lattice of positively-charged ions. Metallic Bonds
18. Metallic bonding accounts for many physical properties of metals, such as strength, malleability, ductility, thermal and electrical conductivity, opacity, and luster.
19. The combination of two phenomena gives rise to metallic bonding: Delocalization of electrons and the availability of a larger number of delocalized energy states than of delocalized electrons. The latter could be called electron deficiency. Nature Of Metallic Bonding
21. Definition : Alloys are materials made up of more than one chemical element, at least one of which must be a metal. ALLOYS
22. For example a small amount of carbon is added to iron to form steel. A certain amount of chromium is added to iron and carbon to form stainless steel, an alloy that is highly corrosion resistant. Although pure gold is highly corrosion resistance, copper is added to it to enhance its strength .
23. A pure metal solidifies at one fixed temperature, a fact which can be checked by plotting a cooling curve. A cooling curve may be obtained by melting a small amount of a metal and recording the temperature drop at suitable time intervals as this metal solidifies (the metal must be allowed to cool very slowly i.e. under equilibrium conditions) . Solidification of metals
24. We can then plot a graph of temperature against time to give us the cooling curve for that particular metal.
25. Nucleus formation As the metal is cooled, clusters of atoms come together from the liquid to form solid crystal nuclei.
26. This nuclei will be stable and grow into crystallites or grains. Nucleation can occur by two processes – Homogenous nucleation Heterogeneous nucleation
27. Mechanism of crystallization Crystallization is controlled by atomic diffusion from melt to the nuclei. Characteristically a pure metal may crystallize in a tree branch pattern from a nucleus. Such formations are called dendrites.
30. In crystallization growth starts from the centre of the nuclei and crystals grow towards each other. When two or more crystals collide their growth is stopped. Finally the entire space is filled with crystals.
31. Stages in the formation of metallic grains during the solidification of a molten metal
32. The metal is therefore made up of thousands of tiny crystals. Such a metal is said to be polycrystalline. Each crystal in the structure is known as a grain.
33. Grain size Factors affecting grain size :– Number and location of the nuclei at the time of solidification Shape of the mould in which the metal solidifies Rate of crystallisation Rate of cooling Cold working Nucleating agents
34. In polycrystalline metal shape of the grains is influenced by the shape of the mold.
35. Control of grain size Smaller the grain size of the metal ,the better its physical properties. Can be controlled to an extent by super cooling and rate of cooling.
36. The latent heat given up by initial solidification raises the temperature in the vicinity of the solidification front and this condition becomes favorable for dendrite growth resulting in columnar grains. If the mold had been cylindrical grains would have grown perpendicular. Such grains are called radial grains.
37. Decreasing the grain size can have a number of beneficial effects on the cast alloy structure of a crown or removable partial denture. The finer grain size can raise the yield stress, increase the ductility and raise the ultimate strength. The change in the grain size is related to the process of plastic deformation and fracture.
38. Grain boundaries The grain boundary is assumed to be a region of transition between differently oriented crystal lattices of two neighboring grains. Structure is more nearly non crystalline, particularly towards the central region of the grain boundary. Impurities in the metal may be found in greater concentration at the grain boundaries. Also this region is readily attacked by chemicals.
40. It has been observed that the position of the neighboring atoms surrounding every atom of a crystal lattice is identical in a pure crystalline metal. When the property of identical periodic points in space was explored mathematically it was discovered there are 14 ways to arrange points in space.
46. Cobalt- chromium & titanium alloys are used in prosthetic dentistry for fabrication of implants Nickel chromium alloys are used for porcelain fused to metal restorations Nickel chromium alloys were introduced for crowns bridges and partial denture frame works Prosthodontic Considerations:-
47. A variety of metal alloys are used in dental specialties. In general they are very strong and stiff and have excellent tarnish and corrosion and are biocompatible. As the grain size becomes smaller the better will be its physical properties. Summary:
48. References:- Givan.D.A, Precious metals in dentistry, Dental Clinics of North America, July, 2007, pg: 591-602. Roach.M, Base metal alloys used for dental restorations and implants, Dental Clinics of North America, July, 2007, pg: 603-628. Wataha.J.C, Alloys for prosthodontic restorations, journal of prosthetic dentistry, 2002, 87 (4), pg 351-363. O’Brien.W.J, Dental materials and their selection, 3rd edition, Quintessence publications.
49. Ferracane.J.L, Materials in Dentistry, 2nd edition, Lippincott Williams and Wilkins. Williams.D.F, Cunnigham.J, Materials in Clinical Dentistry, 1st edition, oxford medical publication. Craig.R.G, Dental Materials, 8th edition, Elsevier publications. Anusavice, Phillip’s Science of Dental Materials, 11th edition, Saunders publications. Alloys for prosthodontic restorations The Journal of Prosthetic Dentistry, Volume 87, Issue 4, Pages 351-363