Intro to Materials

Question 1

What is vital to understand about materials?

Answer 1

• biological, chemical and physical properties
• how to select them for appropriate oral function
• clinical techniques to apply effectively

Question 2

What is a biomaterial?

Answer 2

Any material in contact with biological tissue

Question 3

What do we want materials to match?

Answer 3

The tooth structure

Question 4

What is the difference between enamel and dentine in function?

Answer 4

Enamel is hard and brittle, water resistant and dentine is soft and deforms with load.

Question 5

What happens to enamel when we etch it?

Answer 5

Smear layer is removed leaving a high energy surface.
Differential dissolution of prism boundaries after 20s etch with phosphoric acid.

(same happens in dentine but harder to do it here as you create a rich layer of collagen network due to demineralization of HA)

Question 6

Where do dentinal tubules radiate from?

Answer 6

Radiate from pulp to the exterior cementum or enamel border.

Question 7

Give 4 properties of ideal resotarive materials

Answer 7

• biocompatible
• exhibit properties similar to enamel and dentine
• ability to perform in oral environment
• assist in tissue repair of damaged tissues

Question 8

What are the basic principles for restoration?

Answer 8

• retention of material with tooth structure
• ability to maintain function and protect from further mechanical failure
• prevent formation of recurrent caries
• perform under occlusal load (higher in posterior areas)
• aesthetics

Question 9

What are the 4 main types of material used in the mouth?

Answer 9

• metals
• ceramics
• polymers e.g. resin
• composites

Question 10

Give some preventative dental materials

Answer 10

• dentrifices
• pit and fissure sealants
• materials used for their antibacterial properties
• chlorhexidine to prevent progression of tooth decay

Question 11

What are restorative materials?

Answer 11

Used to replace or repair diseased/damaged tissue

Question 12

What are auxillary dental materials?

Answer 12

Materials used to prepare a restoration but aren’t part of the restoration.

Question 13

What materials are used in each of these commonly?

1) orthodontics
2) filings
3) endodontics
4) crowns
5) bridges
6) implants
7) dentures

Answer 13

1) brackets, bonding cements, wires
2) linings, dentine bonding agents, adhesive cements, hybrid cements
3) sealants, obturating materials
4) impressions, dies, waxes, casting alloys, porcelain, luting cements
5) bonding alloys, ceramic cores
6) titanium, metal alloys
7) acrylic cobalt-chrome, stainless steel, artificial teeth, soft linings, denture cleansers