Introduction to dental materials Lecture 1-2

DR. MD. ARIFUR RAHMAN
BDS (D.U), MPH
ASSISTANT PROFESSOR & DENTAL UNIT HEAD
NORTH EAST MEDICAL COLLEGE DENTAL UNIT
SYLHET, BANGLADESH
INTRODUCTION TO
DENTAL MATERIALS
1drarifur_rahman@yahoo.com

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”.

Science Of Dental Materials
Science of dental materials is a basic
science which deals with physical,
mechanical and biological properties of
dental materials. The study of Science of
dental materials gives the operator a basic
knowledge about the materials. This help
to choose a material and allow him/her to
effectively manipulate it.

The Science of Dental Materials:
“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

History of Dental Materials:
 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

Ancient Egyptian Bridge
Gold wire used to hold pontic crowns.

Oral Environment
 Very demanding.
 There can be
1. Temperature variations.
2. pH Variations.
3. Variations in Masticatory forces.

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

pH Variations
 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 .

Variations in Masticatory Forces
 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.
Tooth Average
force (N)
Second
molar
800
First molar 390
Bicuspids 288
Cuspids 208
Incisors 155

Characteristics of Ideal Materials:
It should be
 Biocompatible –
 Non-toxic, non-irritating, non-allergenic
 Mechanically stable & durable –
 Strong, resistant to fracture
 Resistant to Corrosion –
 Does not deteriorate over time
 Dimensionally Stable –
 Little change by temperature & solvents

Characteristics of Ideal Materials
(cont.):
 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

Characteristics of Ideal Materials:
 Tasteless and Odorless –
 Not unpleasant to patient
 Cleanable/Repairable –
 Easily maintained or fixed
 Cost-effective –
 Affordability vs. benefits/disadvantages

Classification of Dental materials
All dental materials fall under 4 main groups:
1. Polymers.
2. Metals.
3. Ceramics.
4. Composites.

POLYMERS
 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”

METALS
“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)

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

COMPOSITES
 Composite materials (also called
composition materials or shortened
to composites) 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.

CLASSIFICATION
OF
DENTAL MATERIALS

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.

1. PREVENTIVE DENTAL
MATERIALS
 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.

1. PREVENTIVE DENTAL
MATERIALS (Cont.)
 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.

2. RESTORATIVE DENTAL
MATERIALS (Cont.)
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.

Types of Restorative dental
materials
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.

3. AUXILIARY DENTAL MATERIALS
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.

4. TEMPORARY RESTORATIVE
DENTAL MATERIALS
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.

SELECTION
OF
DENTAL MATERIALS

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.

1. Analysis of the problem
 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.

2. Consideration of the
requirements
 Enlist the requirements that a
material must meet.
 Requirements of a material are
dependent upon the situation.

3. Consideration of the available
materials and their properties
 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.

4. Choice of a suitable material
 Final step.
 Narrowing the range of choice.
 Factors:
1. Availability.
2. Ease of handling.
3. Cost effectiveness.

Identification of Restorations:
 “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)

Identification of Restorations:
 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)

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

Direct Fillings:
Posterior Composite Filling
Anterior Composite Filling

Crown:
 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

Bridge:
 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

Bridge:
Missing tooth –
area to be restored
Abutments
Pontic

Bridge:
Anterior bridge on model
Anterior bridge before cementation
How many abutment teeth
does the patient have? 40drarifur_rahman@yahoo.com

Bridge:
Before treatment
After bridge
cementation

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

Inlays vs. Onlays:
Porcelain Inlays
Gold Onlay

Veneers:
 All-porcelain or
acrylic facing for
tooth
 Primarily used for
esthetic reasons
 Can alter shape &
color of existing
tooth

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

Denture:
Full Upper and Lower Denture

Denture:
Removable
Partial Denture
metal clasp for retention

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

Gutta Percha
Post
(Silver Points used to be
used in the canal as a filler.)
(The core is built upon
this post.)

amalgam
postsGutta percha
Build-up
unrestored
pulp

Pediatric Restorations:
Stainless Steel
Crown (SSC):
 Prefabricated
 Cemented

Pediatric Restorations:
Space Maintainer:
 Holds space where
primary tooth was
prematurely lost
 Stainless steel
band/crown with loop
 Fabricated outside of
the mouth; cemented

QUESTIONS???

Introduction to dental materials Lecture 1-2

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Introduction to dental materials Lecture 1-2

Similar to Introduction to dental materials Lecture 1-2 (20)

More from Dr. Md. Arifur Rahman

More from Dr. Md. Arifur Rahman (7)

Recently uploaded

Recently uploaded (20)

Introduction to dental materials Lecture 1-2