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.
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:
cavity:
Gold, Platinum, Palladium, Rhodium,
Gold, Platinum, Palladium, Rhodium,
Ruthenium, Iridium,
Ruthenium, Iridium, Osmium and Silver.
Silver.
There are four main metals: Gold,
metals: Gold,
Palladium,
Palladium, Platinum and Silver.
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.
pattern.

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

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

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

19. CLINICAL
APPLICATION
Scale
Crowns
Fixed partial
Denture
Endopostes

20. PALLADIUM-
PALLADIUM-
SILVER ALLOY
(Pd-
(Pd-Ag)

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

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

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

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

25. SILVER-
SILVER-TIN
ALLOY
(Ag-
(Ag-Sn)

26. These alloys have been used for decades in
dentistry to make deposits, not being
deposits,
suitable for prosthetic purposes.
purposes.
INDICATIONS:
Temporary inlays.
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.
elements.
Is the so called because it reacts with the
environment and are use to protect an
alloy against corrosion by passivity.
passivity.

30. COBALT-
COBALT-
CHROMIUM
ALLOYS
(Co-
(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.
dentures.
Basis of dentures

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

34. ADVANTAGES
Cheap
Very light
More durable adjusting hooks.
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
1. TECHNICAL COMM : Requires the use
of an intermediate (welding).
2. WELD TECHNICAL : Application of heat
to melt the two metal surfaces.
3. ELECTRICAL TECHNICAL : Application
of electric current-tap to join metallic
current-
surfaces.
surfaces.

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