Structure and Properties

Question 1

What are dental composites used for?

Answer 1

Dental composites are used as restorative (filling) materials and also available for special tray construction.

Question 2

What does a dental resin composite consist of?

Answer 2

A dental resin composite consists of:

1. Resin
2. Filler
3. Most importantly a coupling agent

Question 3

Dental fibre reinforced materials are a type of composite filling. What does this type of composite consist of?

Answer 3

Fibres of high strength and modulus that are bonded to a matrix.

Question 4

Why do I need a knowledge of applied materials?

Answer 4

1. to facilitate effective use
2. to permit clinical problem solving
3. to promote effective dialogue within personnel within the profession (eg. Dentists, technicians, nurses, reps, patients).

Question 5

By law, what should be offered to all patients receiving dental appliance?

Answer 5

a Statement of Manufacture

Question 6

What is involved in the statement of manufacture?

Answer 6

1. The patients name and confirmation made for them.
2. The prescribers name and registered address.
3. The technicians name and registered address.
4. A description of the appliance.
5. Confirmation meets legal standards

Question 7

If you fail to provide the statement of manufacture to a patient what happens?

Answer 7

It is seen as a criminal offence.

Question 8

What does the periodontal ligament act as?

Answer 8

A shock absorber socket for teeth.

Question 9

The PDL allows both vertical displacement and bucco-lingual displacement when teeth are hit by a force.

State the range values at which the tooth can be displaced (both vertically and bucco-lingually).

Answer 9

Vertical displacement: 25 – 100 μm

Bucco-lingual displacement: 56 – 108 μm

Question 10

What does a force of 1N do?

Answer 10

Intrudes the tooth

Question 11

What does a force of 15N do?

Answer 11

Flexes the bone and causes pain.

Question 12

What range does the pH fluctuate from in the oral environment?

Answer 12

pH 2 - 12

Question 13

What 5 materials are used by the dental team?

Answer 13

1. Gypsum materials (plaster)
2. Waxes
3. Alloys
4. Polymers
5. Ceramics

Question 14

What institution and organisation publishes standards that protect the user and patient from harmful materials?

Answer 14

• British Standards Institution (BSI)

- International Standards Organisation (ISO)

Question 15

What testing machine is used to characterise materials?

Answer 15

The universal testing machine

Question 16

What are the 4 mechanical properties that a material can have?

Answer 16

It could be:

1. Tensile
2. Compressive
3. Diametral tensile strength
4. Flexural

Question 17

What does it mean if a material is relatively tensile?

Answer 17

It means that the material is relatively resistant to breaking under tension.