1. Principles of Cavity Preparation Flashcards
Cavity design is determined by (3)
Structure and properties of dental tissues
Diseases (caries, periodontal disease, tooth surface loss)
Properties of restorative materials
Types of caries (5)
Pit and fissures Anterior approximal Posterior approximal Smooth surface caries Root caries
When should caries intervention take place
When lesion is cavitated and the patient cannot access the lesion for prevention
What do linings cause (3)
Effect on bonding
Enamel contamination
Protection of plural therapeutic agents
Principles of preparation are driven by (2)
Caries removal
Necessary finishing required for (maximising adhesions, occlusal relationships, ease of patient cleaning, properties of materials used)
When should healthy tooth tissue be removed (3)
Restorative material requires it
Cavity margins are in contact with another tooth surfaces
Cavity margins cross an occlusal contact
Principles of cavity preparation (6)
Identify and remove carious enamel
Remove enamel to identify maximal extent of lesion at DEJ and smooth enamel margins
Progressively remove peripheral dentine caries (DEJ first, then circumferentially deeper)
Only remove deep caries over pulp
Outline form modification (enamel finishing, occlusion, requirements of restorative material)
Internal design modification (internal line and point angles, requirements of restorative materials)
Final cavo-surface margins (4)
Remove unsupported enamel
Smooth CSM and line angles
Ensure no excessively acute line angle transitions and that outline form is smooth and rounded
Check for stress concentrators
Final restoration seal (2)
Check for smooth margins, appropriate CSMA, no unsupported tooth tissue, no stress concentrators, internal anatomy allows adaptation of material
Clean cavity to ensure it is free from debris generated during preparation
Basic principles (4)
Access
Extent
Remove dentinal caries
Modifications
Methods of removal of dentinal caries (3)
Hand-held excavator
Round bur
Chemo-mechanical caries removal
Advantages of composite (7)
Aesthetics Conservation of tooth tissue Support for remaining tooth tissue Adhesion/bonding Command cure Low thermal conductivity Elimination of galvanism
How does amalgam bond to tooth
Mechanical bonding - held in cavity by retention and resistance form
Cavity retention includes
Features of the cavity which prevent the restoration being dislodged in any occlusal direction and anatomical design features (undercuts).
Cavity resistance includes
Features of the internal design of the cavity intended to meet the forces of occlusion and features of the cavity preventing the restoration being dislodged in any other direction as well as dovetails/keys/flat floors
