genral introduction and selcetion of dental materials.

1. Prof. Dr. Tahir Ali Khan
BDS, MDSc, MHR, FICD, Ph.D (Scolar)
Vice principal/Head Deptt: Science of Dental
Materials
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2. • At the end of the lecture you will know
• Different branches of dentistry
• Rationale for Studying Dental Materials
• Structure of Tooth
• Types of dental materials
• Ideal properties of restorative materials
• Selection of dental materials
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Objectives

3. Dentistry
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4. • Branch of medicine
• Consists of the study, diagnosis, prevention, and treatment of
diseases, disorders and conditions of the oral cavity
Dentistry
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5.  Specializes in dentistry
 The diagnosis, prevention, and treatment of diseases and
conditions of the oral cavity
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6. Branches
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7. 7
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8. 88

9. 99

10. 1010

11. 11

12. 12
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13. 1313
Science of Dental materials

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15. 15
1. To Understand the Behavior of Materials
2. To Handle Materials Properly
3. To Assess and Treat the Patient
4. To Educate the Patient
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Rationale for Studying Dental Materials

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17.  It involves study of the
 1. Composition of the materials
 2. Properties of the materials
 3. And the way in which materials interact with the environment in
which they are placed
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18.  Historically a wide variety of materials used as replacement for
 Crown & Root
 Includes
1. Animal teeth
2. Human teeth
3. Bone
4. Seashells
5. Ceramics
6. Metals
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19.  Restorative materials
 Preventive materials
 Auxiliary materials
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21.  Replaced the missing portions of tooth structure
 Evolved more slowly over the past several centuries
 In today’s dentistry
 Metals, Ceramics, Polymers and Composites
 None are permanent despite recent improvements in their
physical properties
 Dentists and materials scientists are still searching for an ideal
restorative materials
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 1. Be biocompatible
 2. Bond permanently to tooth structure or bone
 3. Match the natural appearance of tooth structure
and other visible tissues
 4. Exhibit properties similar to those of enamel,
dentin & other tissues
 5. Be capable of initiating tissue repair or
regeneration of missing or damaged tissues
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23.  Primers, Bonding agents,
 Amalgams, Composites, GIC,
 Metals, Ceramics,
 Ceramics and Denture Polymers
 Restorative Material may further divided into
 Direct Restorative Material
 Indirect Restorative Material
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24.  Pits Fissure sealants,
 Sealing agents that prevent leakage,
 Chlorhexidine or other therapeutic agents
used to prevent or inhibit the progression of
tooth decay
 Acrylic resins from which mouth guards are
formed
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25.  Materials used in the process of fabricating dental
prosthesis & appliances but don’t become part of
these devices.
 Impression materials
 Casting investments
 Gypsum cast & model materials
 Dental Waxes
 Finishing & Polishing abrasives
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26.  Involves
 1. Analysis of the problem
 2. Consideration of requirements
 3. Consideration of available material and
their properties, leading to
 4. Choice of material
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27.  Require: Selection of the material for example
 Selection of filling material, it is important to
decide whether
 The restoration : high stress or low stress area
 Visible when the pt. smiles?
 Is the cavity deep or shallow?
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28.  To develop a list of requirements for a material to meet the need
of that situation
 1. For example, a filling material --- matches tooth color
 Is able to withstand moderately high stresses without fracture ---
-- required
 2. Some cavities are caused by tooth brush/ paste abrasion
 In this case the material used should naturally possess adequate
resistance to definite abrasion
 It is possible to build a profile of the ideal properties required for
the application being considered
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29.  This step is carried out at two levels
 The dentist must choose those materials which are
present in his/her surgery
 Previous experience with materials in similar
circumstances will be a major factor which
influences selection
 The operator must use alternate materials
 Or newer products
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30.  Final choice of material
 Personnel preference on the part of the dentist
 Factors
 Ease of handling
 Availability which may play a part at this stage of the
selection process
 Cost
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31.  Number of available materials increases, it becomes more
and more important for the dentist to be protected from
unsuitable products or materials which have not been
thoroughly evaluated.
 Most manufacturers operate an extensive quality assurance
program and materials are thoroughly tested before being
released to the general practioner.
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32.  Standard specification tests both national and international
standard organizations are now available which effectively
maintain quality levels for some materials
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33.  Solubility test
 Indicates stability of certain materials.
 Special for filling materials.
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34.  Many material produce good result in the lab found lacking
when subjected to clinical use
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35. Thanks
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