week 3- anterior metal ceramic crown

Question 1

what does the shoulder do

Answer 1

marginal integrity

structural durability

Question 2

what does the axial reduction do

Answer 2

retention and resistance

structural durability

Question 3

what does the wing do

Answer 3

R&R

Question 4

what are the prep principles of an anterior metal ceramic crown

Answer 4

→ Adequate room for palatal and lingual thickness of the metal
→ And the metal and porcelain buccally
→ Have retention and resistance forms
→ No undercuts
→ Margins supra gingival where possible
→ Chamfer margin 0.5mm on the palatal aspect
Shoulder margin of 1.2-1.6mm on the buccal aspect for the metal and porcelain

Question 5

what type of reduction to we follow on the palatal aspect

Answer 5

So from the margin you make on the buccal surface- line the tooth up on the longitudinal axis of the buccal surface and just bring it exactly in the same angulation to the palatal aspect
This is to ensure we get optimum retention as well as following the tooths normal morphology

Question 6

how many planes do we have on the buccal surface

Answer 6

2 planes of reduction

Question 7

final criteria for the anterior metal ceramic crown

Answer 7

→ Depth-grooves incisally (2mm)
→ Incisal reduction (sloping gingivally towards palatal side)
→ Initial labial reduction in 2 planes (chamfer)
→ Palatal margin (0.5 mm chamfer)
→ Palatal reduction (0.5 – 0.7 mm)
→ Inter-proximal reduction (long thin tapered and chamfer diamonds)
→ Labial shoulder (1.2- 1.5mm)
→ Finish margins/check for undercuts
No sharp corners

Question 8

why is a two plane reduction necessary

Answer 8

If there is not a two plane reduction it can lead to the pulp being compromised