Intro to Fixed Pros and Full Coverage Preps

Question 1

What is centric relation?

Answer 1

TMJ Dependent position- Independent of tooth position

Question 2

What is MIP (Maximum Intercuspation)?

Answer 2

Tooth Dependent position- Independent of Condyle position

Question 3

When should you consider fixed pros/full coverage preparation?

Answer 3

• previous extensive coronal destruction (caries, trauma, previous restorations, endo)
• maximum retention and resistance form is needed
• axial and occlusal contours require substantial correction

Question 4

When should you not consider fixed pros/full coverage preparation?

Answer 4

• when a more conservative restoration can function (partial veneer crown, etc.)
• esthetics

Question 5

What is the sequence of a complete metal crown preparation?

Answer 5

• occlusal reduction/functional cusp bevel
• axial reduction
• priximal reduction
• secondary retentive features
• margination

Question 6

What are the tools/process for occlusal reduction?

Answer 6

1. depth-orientation grooves
2. round-end taper diamond (5856L-016)

Question 7

What are the measurements of the functional cusp bevel?

Answer 7

1.5 mm tapers to 1.0 mm

Question 8

What is the chamfer margin (mm)?

Answer 8

0.5 mm

Question 9

What is the axial reduction (in mm)?

Answer 9

0.5-1.0 mm

Question 10

What bur is used for the retention groove?

Answer 10

full depth of 170L bur

Question 11

What side of the tooth should the retention groove be placed?

Answer 11

buccal

Question 12

What are the morphologic occlusal reduction measurements for functional cusp, central fossa, and non-functional cusp?

Answer 12

functional cusp - 1.5 mm
central fossa - 1.5 mm
non-functional cusp - 1.0 mm

Question 13

What does beveling the functional cusp do?

Answer 13

• completes occlusal reduction
• realigns the functional cusps with the opposing central groove
• provides uniform 1.5 mm occlusal clearance

Question 14

What are the steps for the facial and lingual axial reduction?

Answer 14

• determine the path of draw before starting axial wall prep
• consider the ideal orientation for each axial wall
• reduce 0.5-1.0 mm
• 6-10 degrees of taper TOC of opposing walls

Question 15

If you skip the facial and lingual axial reduction step what will happen to the crown?

Answer 15

over contoured

Question 16

What bur should you use for the proximal axial reduction?

Answer 16

• needle chamfer diamond
  or
• small chamfer diamond