Principles of Cavity Preparation Flashcards
What determines the design of a cavity
Structure and properties of the dental tissue
The disease present
Properties of restorative materials
What must be reviewed and reassessed continually when preparing a cavity
The position of the caries
The extent of the caries
The shape of the prepared cavity
The final restorative material
What are the different positions caries can be found in
Pit and fissure
Approximal - posterior and anterior
Smooth surface
Root
When should you intervene with caries
If the lesion is cavitated
If the patient can’t access the lesion for prevention
If the lesion is into dentine radiographically
If the lesion is causing a pulpitis
If the lesion is unaesthetic
How does dentinal caries usually spread
Laterally along the ADJ
When should healthy tooth tissue be removed
If the material used for the restoration requires it
If the margins of the cavity are in contact with another tooth surface
If the margins of the cavity cross an occlusal contact
What are the principles of cavity preparation
1) Identify and remove carious enamel
2) Remove enamel to identify the maximal extent of the lesion at the ADJ and smooth the enamel margins
3) Progressively remove peripheral caries in dentine - from the ADJ first then circumferentially deeper
4) Only then remove deep caries over the pulp
5) Outline form modification
6) Internal design modification
Describe the properties of a cavity before it is restored
Smooth margins Appropriate CSMA No unsupported tooth tissue No stress concentrator Internal anatomy that allows adaptation of a material
Describe how the first principle of cavity preparation should be carried out
Apply dam
Remove overlying enamel with a high-speed bur to gain access to carious dentine
Describe how the second principle of cavity preparation should be carried out
Clear all caries at the ADJ Check staining at ADJ Smooth enamel cavo-surface margins Examine adjacent contact for caries Avoid trauma to adjacent tooth
How should secondary caries be accessed
Use a high-speed bur to remove a restoration
Start from the centre of the restoration and cut towards the edge of the cavity
Remove all the restoration and any underlying base material
Consider waste disposal as materials can be hazardous
Describe how the third principle of cavity preparation should be carried out
Detect dentinal caries as a brown stain or softened tissue when using a sharp probe as sound dentine shouldn’t yield under probing
Remove caries first from the ADJ and last from the pulpal flood
How should caries from the pulpal floor be removed
Hand-held excavator
Round bur
Chemo-mechanical caries removal
Describe how the fourth principle of cavity preparation should be carried out
Decide which restorative material to use
Modify the cavity preparation as appropriate:
Enamel margins CMSA, occlusion internal anatomy, dentine quality
What are the most common restorative materials used for direct restorations
Composite
Amalgam
