This document discusses various metals used in dentistry, including their properties, applications, and alloys. It covers precious metals like gold, semiprecious metals like palladium-silver alloys, and base metals like cobalt-chromium. The properties, advantages, disadvantages, and clinical applications of different alloy types are described. Welding techniques and requirements for joining dental metals are also summarized.

1. Metallic Restorations
Student: Alonso Martinez Tapia
Dr. Alfredo Nevarez Rascon

2. METALS

3. DEFINITION
“Chemical substance that
is a good electrical and
thermal conductor,
when is polished is a
good reflector “

4. FEATURES
 SHINE
 RESISTANCE TO CORROSION
 THERMAL AND ELECTRICAL
CONDUCTOR
 STRENGTH AND RIGIDITY
 DRIVE RESISTANCE

5.  ALLOY : This are unions of 2 or more
metallic elements.

6. In Dentistry, alloys are use
except for:
• pure gold laminated
• commercial pure titanium
• Silver points for endodontic

7. CHANGES IN THE METAL
STRUCTURE
 lackluster : Loss of gloss or sheen in a alloy or
metal surface.
 Pigmentation : Partial impariment on metal
surface, or color change.
 CORROSION : Actual deterioration on metal
surface.

8. • FACTORS CAUSING CORROSION
– pH of the saliva.
– Wrong adapted prosthesis.
– Poor dental position.
– Deposits of food.
– Poor hygiene.
– Food that release certain chemical
components.
– Drugs.
– Fluctuations in temperature.

9. ALLOYS USED IN DENTISTRY
Highly noble alloys (precious)
Alloys of noble metals
Predominantly base alloys

10. PRECIOUS METALS
Corrosion resistance in the oral cavity:
Gold, Platinum, Palladium, Rhodium,
Ruthenium, Iridium, Osmium and Silver.
There are four main metals: Gold,
Palladium, Platinum and Silver.

11. Cast Metal Or Drain
Process for the constuction of a
restoration or appliance out for the
previously made a mouth waxed or
pattern.

12. CAST ALLOYS FOR HIGHLY NOBLE
Composition:
2. Gold: malleability, resistance to
corrosion.
3. Silver: Hardness
4. Zinc: decreases T fusion
5. Platinum or Palladium: Hardness
6. Copper: resistance and
bactericidal
Nota: the white gold casting whit less gold
and copper are not.

14. TIPOS DE OROS PARA COLADOS
Type I (SOFT GOLD)
For the construction of scale in class III y V
 Type II (MEDIUM GOLD)
For all types of deposits, plus ¾ cr owns and
complete
 Type III (HARD GOLD)
For small fixed bridges and removable
 Type IV ( GOLD EXTRA HARD)
For large fixed bridges and removable palatal
bars and lingual

15. NOBLE METAL ALLOYS
(Semiprecious)
 25% of noble metals, does not require
gold:
 Silver - Palladium
 Palladium - Silver
 Silver - Tin

16. SILVER-
PALLADIUM
ALLOYS
(Ag-Pd)

17.  Developed as an alternative to those based
on gold. There are two varieties:
Silver 60-70% Palladium 25-30%
Note: Some containe 10% copper.
Palladium 60% Silver 30%
Note: El 10% of other metals to failitate
bonding with porcelain.

18. CHEMICAL PROPERTIES
 Pigmentation and resistance to corrosion
properly handled.
Note: It is possible to achieve adequate
accuracy casting and a good polishing and
acceptable welds.

19. CLINICAL
APPLICATION
 Scale
 Crowns
 Fixed partial
Denture
Endopostes

20. PALLADIUM-
SILVER ALLOY
(Pd-Ag)

21. They are an alternative
to gold alloy for
ceramics.

22. This are alloys of high melting
point and which support the
firing of ceramics of porcelain.
(1400°C)

23. ADVANTAGES
 Good physical properties and bonding
with ceramics.
 Biocompatible

24. DISADVANTAGES
The likely change in color of
porcelain baked.
Expensive

25. SILVER-TIN
ALLOY
(Ag-Sn)

26. These alloys have been used for decades in
dentistry to make deposits, not being
suitable for prosthetic purposes.
INDICATIONS:
Temporary inlays.

27. ADVANTAGES
Cheap
Easy handling
Poor precision casting

28. DISADVANTAGES
 Fragile marginal edges
 Pigmentation
 Can not be welded
 Slight corrosion resistance
 After a short clinical use and even
before cemented in the mouth have
lost shine and later changed to dark

29. BASE METALS
 These are noble elements.
 Is the so called because it reacts with the
environment and are use to protect an
alloy against corrosion by passivity.

30. COBALT-
CHROMIUM
ALLOYS
(Co-Cr)

31. FEATURES
High hardeness
Good gloss
Mechanical strength
Resistance to corrosion
y corrosión
Cheap

32. CLINICAL
APPLICATION
Development of
bases in removable
dentures.
Basis of dentures

33. PRESENTATION
Form of granules
Ingots
TRADE NAMES
 Vitalium (Co-Cr)
 Ticonium (Ni-Cr)
 Dentillium (Fe-Cr)

34. ADVANTAGES
Cheap
Very light
More durable adjusting hooks.

35. DISADVANTAGES
• Excessive hardness
• Minor casting accuracy
• Complicated heat treatment

36. Welds

37. Welds
WELDING : Intermediate
element that is used to
join metallic surfaces
each other.
It’s a technique for join 2
Or more metal elements,
Rebuild or repair a metal
surface
.

38. REQUIREMENTS
Free toxic substance
Resistant
Flow
Similar color
Lower temperature of
• fusion
Corrosion resitant

39. TECNICAS PARA SOLDAR
TECHNICAL COMM : Requires the use
of an intermediate (welding).
WELD TECHNICAL : Application of heat
to melt the two metal surfaces.
ELECTRICAL TECHNICAL : Application
of electric current-tap to join metallic
surfaces.

40. FLUX
Facilitate the flow of welding,
Eliminating impurities.
They come in powder and paste
Composition of flux for alloys with
chromium :
pottasium fluoride, boric acid, borax glass,
and sodium carbonate or silica. And for
gold alloys: Borax powder, boric acid and
silica.