Question 58

Question 1

crown prep faults principles

Answer 1

o Preservation of tooth structure
o Retention and resistance form
 6 degree taper, long walls, retention grooves/slots, path of insertion
o Structural durability
 Sufficient occlusal reduction, functional cusp reduction/bevel and axial reduction
o Marginal integrity
 Chamfer and shoulder
o Preservation of the periodontium
 Smooth, cleansable, placed at gingival margin where possible (may need to be subgingival – but avoid encroaching on biological width)
 Aesthetic considerations
 Smile lines

Question 2

stages in prep of crown

Answer 2

o Occlusal reduction
o Separation
o Buccal reduction (2 planes)
o Palatal or lingual reduction
o Shoulder and chamfer finish
o Check occlusal surface and clearance

Question 3

reduction measurments

Answer 3