Using resin composites 1

Question 1

What is the composition of composite?

What is the activator for light cure composite?

Answer 1

Made up of Resin Matrix with a Filler

• resin matrix is always a methacrylate monomer
• with the principle monomers BISGMA/Urethane Dimethacrylate
• Filler: Particles of silica based glass
• Silane coupling agent allows resin and filler particles to bond together
• Activator for light cure composite: Camphorquinone

Question 2

How are resin composites classified?

Answer 2

Classified by filler particle size

1. conventional/macro
2. micro/nanofilled
3. hybrid.

Question 3

Why do we need to place composites using Oblique layering technique making sure to avoid contacting both walls of cavity when placing?

Answer 3

To avoid polymerisation shrinkage

Question 4

Why do you do let composite (e.g. HEMA) touch skin or gloves?

Answer 4

Hypersensitivity to components of composite (e.g. HEMA)

could be career ending

Question 5

What are the advantages of Resin composites?

Answer 5

• Wear resistance and compresive strength matches tooth substance.
• command set
• Good aesthetics – tooth coloured
• Bonded to tooth – more conservative of tooth tissue

Question 6

What are some Techniques to Overcome Polymerisation Shrinkage?

Answer 6

Keep operator field as dry as possible

Place in oblique increments

Question 7

What are the Resin composite clinical indications?

Answer 7

All classes of restoration where there is enamel margins - cannot place composite on root surface.

• Anterior teeth – Class III, IV and V
• Posterior teeth – Class I, II and V
• Deciduous restorations - cannot place amalgam in children under 15.

Question 8

When to intervene with a Anterior Class III cavity?

Answer 8

• Caries reached ADJ
• Obviously cavitated

Question 9

What is when restoring a anterior class IV cavity?

Answer 9

Aim – to recreate incisal edge and mesial or distal corner of tooth