BDS 1ST AND 2ND YEAR DENTAL MATERIALS

1. INTRO TO DENTAL MATERIALS

2. SCIENCE OF DENTAL
MATERIALS
• Is defined as,
• “The Study of composition and properties of
dental materials and the manner in which they interact
with the environment they are placed”.

3. 3“Why are we studying this field?”
1. for the knowledge to make optimal selection of
materials
2. To understand the behavior of the materials, use,
handling, manipulation
3. Safety considerations of the materials
4. Patient education regarding dental restoratives
5. Recognition of materials – proper care of
prostho/restorations
6. Understand the professional literature

4. HISTORY OF DENTAL
MATERIALS:
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 Dating as early as 500 B.C. - present
 Metals – gold
 Plaster and wax models
 Prosthetics of bone, ivory, wax, metals
 Porcelains – late 1700’s
 Amalgam – early 1800’s
 Acrylics – 1940’s
 Adhesive dentistry – 1970’s - present

5. FACTOR WHICH AFFECTING
SELECTION OF DENTAL
MATERIA

6. ORAL ENVIRONMENT
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1. Temperature variations.
2. pH Variations.
3. Variations in Masticatory forces.

7. TEMPERATURE
VARIATIONS
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 Normal temperature of oral cavity (32℃ to
37℃).
 On intake of a cold/hot food or drink
temperature range increases (0℃ to
70℃).

8. PH VARIATIONS
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 pH of saliva is neutral (7.0)
 On intake of acidic fruit juices or
alkaline medicaments, pH may
vary from 2.0 to 11.0 .

9. VARIATIONS IN
MASTICATORY FORCES
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 Muscles of
Mastication apply
forces to the dentition.
 Masticatory forces
vary from tooth to
tooth.
 Average force applied
by the tooth increases
from anterior to
posteriors.
T
ooth Average
force (N)
Second
molar
800
First molar 390
Bicuspids 288
Cuspids 208
Incisors 155

10. CHARACTERISTICS OF IDEAL
MATERIALS:
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 Biocompatible –
 Non-toxic, non-irritating, non-allergenic
 Mechanically stable & durable –
 Strong, resistant to fracture
 Resistant to Corrosion –
 Does not deteriorate over time

11. 11
 Minimal conduction –
 Insulates against thermal/electrical change
 Esthetic –
 Looks like oral tissue
 Easy to manipulate –
 Minimal/reasonable effort & time needed
 Adheres to tissues –
 Retains onto, and seals, tooth structure

12.  Tasteless and Odorless –
 Not unpleasant to patient
 Cleanable/Repairable –
 Easily maintained or fixed
 Cost-effective –
 Affordability vs. benefits/disadvantages
 Dimensionally Stable –
 Little change by temperature & solvents

13. MATERIALS USED IN
DENTISTRYS
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All dental materials fall under groups:
1. Polymers.
2. Metals.
3. Ceramics.
4. Composites.

14. POLYMERS
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 Chemical compound consisting of large
organic molecules formed by the union of
many smaller monomer units is called a
“POLYMER”
 Chemical reaction in which low molecular
weight monomers are converted into high
molecular weight polymer chains
“POLYMERIZATION”

15. METALS
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“An opaque lustrous chemical
substance that is a good conductor of
heat and electricity, and when
polished is a good reflector of light”.
The Metals Handbook (1992)

16. CERAMICS
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 “An inorganic compound with non
metallic properties, typically
composed of metallic (or semi-
metallic) and non metallic elements.”

17. COMPOSITES
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 Composite materials are materials
made from two or more
constituent materials with
significantly different physical or
chemical properties, that when
combined, produce a material with
characteristics different from the
individual components.

18. CLASSIFICATION OF
DENTAL MATERIALS
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19. CLASSIFICATION OF DENTAL
MATERIALS
• Dental materials can be classified as:
1. Preventive dental materials.
2. Restorative dental materials.
a) Direct restorative dental materials.
b) Indirect restorative dental materials.
3. Auxiliary dental materials.
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20. 1. PREVENTIVE DENTAL
MATERIALS
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 Basic aim is to provide resistance to the
progression of an active carious lesion.
 Carious lesion cause the demineralization of
the dental enamel.
 These include:
a)Chemotherapeutic agents like Dentifrices,
Mouthwashes and cavity varnishes.
b) Pit and fissure sealants.
c) Floride releasing cements.

21. 21
 Preventive dental materials can also serve
as Restorative materials.
 Can be either,
1) Short time periods.
2) Moderately long time period.
3) Longest time periods.

22. 2. RESTORATIVE DENTAL
MATERIALS
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Help to repair or replace defected tooth structure.
These include:
1. Amalgam.
2. Bonding agents.
3. Resin based composites.
4. Compomers.
5. Ceramics.
6. Liners.
7. Cement bases.
8. Dental polymers.

23. TYPES OF RESTORATIVE
DENTAL
MATERIALS
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a) Direct restorative materials:
 Used intraorally.
 fabricate restorations / prosthetic devices
directly on the teeth or tissues.
a) Indirect restorative materials:
 Used extra orally.
 Formed indirectly over a cast or models.

24. 3. AUXILIARY DENTAL MATERIALS
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Materials used in the process of fabricating
dental prosthesis. These include:
1. Impression materials.
2. Dental waxes.
3. Gypsum casts and model materials.
4. Finishing and polishing abrasives.
5. Acrylic resins for impressions.
6. Acid etching solutions.

25. 4. TEMPORARY RESTORATIVE
DENTAL MATERIALS
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Sub category of restorative materials. Intended to
be used to restore the tooth temporarily. These
include:
1. Orthodontic wires.
2. Cements used as temporary liners.
3. Cements used as temporary filling materials.
4. Acrylic resins used for inlays, inlays, crowns
and fixed partial dentures.

26. SELECTION
OF
DENTAL MATERIALS
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27. SELECTION OF DENTAL
MATERIALS
1. Analysis of the problem.
2. Consideration of the
requirements.
3. Consideration of the available
materials and their properties.
4. Choice of a suitable material.
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28. 1. ANALYSIS OF THE PROBLEM
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 Basic and very important step.
 Incorrect analysis may lead to wrong
treatment plan.
 Poor prognosis and failure of
treatment.
e.g. Selection of a filling material.

29. 2. Consideration of the
requirements
 Enlist the requirements that a
material must meet.
 Requirements of a material are
dependent upon the situation.
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30. 3. CONSIDERATION OF THE
AVAILABLE MATERIALS AND
THEIR PROPERTIES
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 Clear concept about the properties.
 In case of immediate problem,
Must choose from the materials in hand.
 Dentist must be up to date with the
advancements.
Thorough comparison of Properties of the
available materials with requirements.

31. 4. CHOICE OF A SUITABLE
MATERIAL
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 Final step.
 Narrowing the range of choice.
 Factors:
1. Availability.
2. Ease of handling.
3. Cost effectiveness.

32. IDENTIFICATION OF RESTORATIONS:
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 “Dental Restoration” –
 Restores function & appearance of oral
structure lost by pathology, injury, or is
congenitally missing
Examples:
 Pathology – caries: filling
 Injury – broken tooth: crown
 Congenitally Missing: prosthetic (i.e. bridge)

33. IDENTIFICATION OF RESTORATIONS:
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 Direct Restoration –
 A restoration that is created and placed
directly into the prep site of the tooth
(i.e. amalgam filling, composite filling)
 Indirect Restoration –
 A restoration that is created outside of the
mouth on a model of the prepped tooth and
later fixed into the mouth
(i.e. gold crown, denture)

34. DIRECT FILLINGS:
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 Usually made of
amalgam (“silver”
metal) or composite
(acrylic) materials
 For caries of various
degrees; anterior or
posterior teeth Posterior amalgam fillings

35. Posterior Composite Filling
Anterior Composite Filling

36. CROWN
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 Indirect restoration
to replace missing
crown of tooth, or
protect remaining
crown of tooth
 Caries, fractures,
teeth with RCT,
esthetics
 Made of porcelain,
metals, or both
Porcelain-Fused-to-Metal (PFM) Crown

37. BRIDGE:
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 An indirect restoration; to replace one or
more missing teeth
 “fixed” – not removable; cemented to
existing teeth
 Made of porcelain, metals, or both
 Abutment – the existing tooth/teeth
supporting the bridge
 Pontic – the replacement tooth

38. BRIDGE
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Missing tooth –
area to be restored
Abutments
Pontic

39. BRIDGE
Anterior bridge on model
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Anterior bridge before cementation
How many abutment teeth
does the patient

40. Before treatment
After bridge
cementation
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41. INDIRECT RESTORATIONS:
 Inlay –
 A fabricated restoration made of metal or
porcelain that replaces missing tooth
structure; does NOT include the restoration
of any cusps
 Onlay –
 A fabricated restoration (as above) that
DOES include the restoration of at least
one cusp
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42. Porcelain Inlays
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Gold Onlay

43. VENEERS:
 All-porcelain or
acrylic facing for
tooth
 Primarily used for
esthetic reasons
 Can alter shape &
color of existing
tooth
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44. DENTURE
 The removable dental prosthetic used to
replace all of the teeth in an arch;
patient is edentulous.
 Made of acrylic (teeth may be porcelain)
 “Partial Denture” – replaces some teeth
in the arch; patient is partially
edentulous.
 Made of acrylic usually with metal
substructure and clasps
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45. DENTU
RE:
Full Upper and Lower
Denture
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46. Removable
Partial Denture
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metal clasp for retention

47. ENDODONTIC RESTORATIONS:
 “Endodontic” – “inside” the tooth; root
canal treatment (RCT)
 Gutta percha – used to fill the canal
 Post and Core –
The post is a metal piece that is screwed
into and cemented into the root canal
The core is built-up around the post to
create more available tooth structure
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48. Post
(The core is built upon
this post.)
Gutta Percha
(Silver Points used to be
used in the canal as a filler.)
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49. ENDODONTIC RESTORATIONS:
amalgam
posts
Gutta percha
Build-up
unrestored
pulp
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50. PEDIATRIC RESTORATIONS:
Stainless Steel
Crown (SSC)
 Prefabricated
 Cemented
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51. PEDIATRIC RESTORATIONS:
Space Maintainer:
 Holds space where
primary tooth was
prematurely lost
 Stainless steel
band/crown with loop
 Fabricated outside of
the mouth; cemented
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52. QUESTIONS??
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