Lec 2 Properties, Advantages, Disadvantages, Indications, Contraindications

Question 1

Enumerate the 6 properties of composites.

Answer 1

1. Linear coefficient of thermal expansion
2. Water sorption
3. Wear resistance
4. Surface texture
5. Radiopacity
6. Modulus elasticity

Question 2

The change in length or dimension of a solid material when heated or cooled.

Answer 2

Linear coefficient of thermal expansion

Question 3

Amount of water adsorbed on the surface and into the body of the material. Absorbing moisture may result in staining or slight enlargement / expansion.

Answer 3

Water sorption

Question 4

Ability to resist surface loss.

Answer 4

Wear resistance

Question 5

Surface smoothness or roughness.

Answer 5

Surface texture

Question 6

An optical property to enhance the color match to the tooth.

Answer 6

Radiopacity

Question 7

This property is important because more opaque composites will allow clinicians to easily determine recurrent caries around restorations in radiographs.

Answer 7

Radiopacity

Question 8

In what Class restorations are composites indicated for?

Answer 8

All classes (1, 2, 3, 4, 5, 6)

Question 9

What are the 3 contraindications of composite restorations?

Answer 9

1. Inability to isolate the site.
2. Excessive masticatory forces.
3. Restorations extending beyond the root surface.

Question 10

Additional info!

Why are composite restorations contraindicated for those extending beyond the root surface?

Answer 10

• It may result in gap formation.
• It’s difficult to isolate / reach the site, making it difficult to be light-cured.
• It’s better to use Glass Ionomer since it has anticariogenic effect, protecting or preventing possible root caries.

Question 11

TRUE OR FALSE.

Composite restorations are conservative.

Answer 11

TRUE

Question 12

TRUE OR FALSE.

Composite restorations result in good retention and low microleakage when bonded to tooth structure.

Answer 12

TRUE

Question 13

TRUE OR FALSE

Composite restoration are more complex when preparing the tooth.

Answer 13

FALSE.

It is LESS COMPLEX to prepare (only requires to remove the carious structures / defects).

Question 14

TRUE OR FALSE

Composite restorations are not repairable.

Answer 14

FALSE.

It is REPAIRABLE.

Question 15

TRUE OR FALSE

Composite restorations have HIGHER linear coefficient of thermal expansion.

Answer 15

TRUE

Question 16

TRUE OR FALSE

One of the disadvantages of composites is that it may result to GAP FORMATION when it extends to the root surface.

Answer 16

TRUE

Question 17

TRUE OR FALSE

Composite restorations are technique sensitive.

Answer 17

TRUE

(Multiple steps, require NO moisture contamination, light curing, filling by small increments)

Question 18

TRUE OR FALSE

Composite restorations are INSULATIVE, having LOW thermal conductivity.

Answer 18

TRUE

Question 19

What are the 7 indications of composite restorations?

Answer 19

1. Class I, II, III, IV, V, VI
2. Foundations or core buildup.
3. Sealant and preventive resin restorations (thin coatings on occlusal surfaces to prevent caries)
4. Esthetic enhancement procedures
5. Luting (to glue / bond fixed prosthesis to teeth)
6. Temporary restorations
7. Periodontal splinting (to stabilize mobile teeth & promote healing)

Question 20

Give the 5 disadvantages of composite restorations.

Answer 20

1. May result in gap formation when extended to root surfaces.
2. Technique sensitive
3. Expensive
4. May exhibit more occlusal wear in areas with higher stresses.
5. Higher linear coefficient of thermal expansion.

Question 21

Relative stiffness / rigidity of a material.

Answer 21

Modulus elasticity

Question 22

Physiological wear when teeth occlude or articulate.

Answer 22

Wear resistance