Transcript MISCELLANEOUS DENTAL MATERIALS

BY
DR KHAWAJA RASHID HASSAN
HEAD SCIENCE OF DENTAL MATERIALS
DEPARTMENT
W.M.D.C
ABBOTTABAD
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Materials used in MAXILLOFACIAL
SURGERY.
Materials used in ENDODONTICS.
Materials used in PERIODONTICS.
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INTRODUCTION
Maxillofacial materials are used to correct facial
defects.
CAUSES OF FACIAL DEFECTS
Cancer surgeries.
Accidents.
Congenital deformities.
NOSES, EARS, EYES, ORBITS & OTHER
PARTS OF HEAD AND NECK REGION ARE
REPLACED BY THESE PROSTHESES
PROSTHETIC EYE
PROSTHETIC EAR
PROSTHETIC NOSE
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Following materials are used for the fabrication
of maxillofacial prostheses.
POLYMETHYLMETHACRYLATE.
POLYURETHANE.
ROOM TEMPERATURE-VALCUNIZED
SILICONES.
OTHER ELASTOMERS.
1)
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POLYMETHYLMETHACRYLATE:
P.M.M.A was once commonly used for
maxillofacial prostheses.
Still used occasionally to make artificial facial
parts.
Look quiet realistic once properly pigmented.
Hardness & stiffness of P.M.M.A is the main
disadvantage.
2) POLYURETHANE:
a)
b)
c)
d)
Used as maxillofacial materials.
Formed by the reaction of diisocyanate &
polyol in the presence of an initiator.
Reaction must be carried out in a dry
atmosphere or carbon dioxide will result.
Processing temperature of 100 ̊C is
reasonable.
3) ROOM TEMPERATURE VALCUNISED
SILICONES:
a) Because of good physical & mechanical
properties & favorable processing
characteristics RTV-Silicones have become
popular maxillofacial materials.
b) Used more often than any other material for
fabrication of maxillofacial prosthesis.
c) They are easy to color.
4) OTHER ELASTOMERS:
a) Several elastomers have been investigated for
use as maxillofacial materials, including
b) Aliphatic polyurethanes.
c) Chlorinated polyurethane.
d) Organophosphazenes.
e) Silicone poly(methyl meth acrylate) block
polymers.
Endodontics is concerned
with the physiology,
morphology & pathology
of the human dental pulp
& periradicular tissues
Treatments include:
a)
Capping of exposed vital
pulp.
b)
Sealing of root canal
space after removal of
infected pulp.
c)
Reconstruction with
endodontic post & core
systems in case of badly
broken down tooth.
Vital pulp capping:
Two types
Indirect pulp capping
Direct pulp capping
a)
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PULP CAPPING MATERIALS:
Calcium hydroxide cement.
Dentin bonding agents.
b) ROOT FILLING MATERIALS:
Most widely used root canal filling materials are
basically a combination of
I.
Obturating points
&
II.
Canal sealer cements.
I) OBTURATING POINTS
A) Gutta percha points.
B)
Metal points.
A)
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GUTTA PERCHA
POINTS:
Gutta percha is a
rubber obtained from
the trees in Malaysia.
Was introduced in U.K
IN 1843.
Thermoplastic
material.
Softens at 60-65 ̊C &
melts at about 100 ̊C.
Cannot be heat sterilized
but can be disinfected.
Gutta percha when cooled
rapidly forms a crystalline β phase
whereas when cooled slowly a
denser crystalline α phase is
formed.
α phase gutta percha has better
thermoplastic characteristics and
hence preferred to be used in hot
gutta percha systems
OBTURA II
OBTURA III
COMPOSITION OF GUTTA PERCHA POINTS
CONSTITUANT
AMOUNT (%)
PURPOSE
GUTTA PERCHA
19-22
RUBBER
ZINC OXIDE
59-75
FILLER
HEAVY METAL
1-17
RADIO-OPACIFIER
SALTS
WAX or RESINS
1-4
PLASTICIZER
B) METAL POINTS:
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Metals including gold, tin, lead & silver had
been used as root canal filling materials.
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Silver points were used mostly because of
bactericidal effect.
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Rigidity & ability to get corroded easily were
the 2 main disadvantages of silver obturating
points.
IDEAL PROPERTIES OF ROOT CANAL
SEALER CEMENTS
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Should be biocompatible.
Should be bacteriocidal or atleast bacteriostatic.
Easy to use.
Should be insoluble.
Should be free of air bubbles when mixed.
Floe to thin film thickness.
Should adapt to the canal walls & obturating
points.
Should be radiopaque.
Should be easily removed in case of failure.
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ROOT CANAL SEALER MATERIALS:
ZINC OXIDE EUGENOL.
GLASS IONOMER CEMENT.
CALCIUM HYDROXIDE CEMENT.
POLY DI METHYSILOXANE.
PREFABRICATED POSTS:
Metal posts
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2)
3)
4)
Non threaded parallel sided posts.
Threaded parallel sided posts.
Non threaded tapered posts.
Threaded tapered posts.
Fibre reinforced resin posts
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1)
2)
Carbon fibre reinforced posts.
Glass fibre reinforced posts.
Ceramic posts
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1)
2)
3)
Cosmopost.
Biopost.
Cetapost.
1)
2)
3)
Zinc oxide eugenol formulation.
Zinc oxide fatty acid formulation.
Formulation including polyacrylic acid, poly
ethyl methacrylate, zinc oxide,
n-butylphthalate & alcohol.
GOOD LUCK
FOR YOUR
PROFESSIONAL
EXAMZ