Class III Composite Resin Restorations

Question 1

When should anterior teeth be restored?

Answer 1

Unless cavitated or aesthetically unpleasing these teeth should not be restored.

Instead, remineralizing agents should be used then reassess.

Question 2

What kinds of restorative materials should be used for class III restorations generally?

Answer 2

Tooth coloured due to aesthetics

Determined by surrounding dental tissue

Question 3

How does surrounding dental tissue control which method should be used?

Answer 3

If margins are all in enamel and surface is cavitated - restore with composite resin. 90 degree cavosurface line angles on surface under function. Bevel margins at an aesthetic margin

If margins are all in enamel - deep cavity: Combination of materials can be used such as GIC liner/base deep and then composite.

If margins are only in dentin - root surface caries: GIC if aesthetics are paramount, then composite is used to overlay the GIC or resin modified GIC is used.

If margins are in enamel and dentin: GIC layer within dentin margins and composite within the enamel margins (open sandwich technique)

Question 4

What are the 5 advantages of adhesive dentistry?

Answer 4

1. More tooth structure can be preserved
2. Aesthetics are vastly increased
3. Decreased microleakage (at the tooth-restoration interface)
4. Easily repaired
5. A more rounded shaped prep can be used.

Question 5

Where do caries usually occur in conventional class III restorations?

Answer 5

Just below the contact point

Question 6

When is a labial access better than a lingual access?

Answer 6

Labial access:

Only used when too much healthy tooth will be lost

When carious lesion extends to labial surface

When replacing an old restoration

Prepared from labial aspect

Rotated teeth.

Question 7

What should be done before accessing the anterior teeth?

Answer 7

1. Identify where the caries is positioned.
2. Minimize amount of healthy tooth structure that needs removal for convenience form. (adjust approach angle of the bur)
3. Avoid harming the adjacent tooth.
4. Try to maintain access to the contact point. (if not possible note extent and position to reproduce in new restoration)
5. Remove demineralized enamel. (Aesthetics may demand removal of stained enamel, composite requires mineralised enamel at cavity margins. Remove sufficient enamel to ensure the full extent of carious dentin is accessible and DEJ is visible)

Question 8

Where should the access cavity be bevelled?

Answer 8

Always in sound enamel

45 degrees away from the tooth surface

Small Class III: 0.5 - 1.0 mm bevel

Large Class III: > 1mm

Question 9

Where should the the access cavity not be bevelled?

Answer 9

Thin enamel

Margins close to the DEJ

Margin in cement

Areas of occlusion

Question 10

When should class III restorations be lined?

Answer 10

Line pulpal aspect of the cavity only

Keep lining material away from the enamel

Keep lining out of retention features if these are used