Tooth Prep for FCC

Question 1

Fabrication of prep template

Answer 1

1. base and activator
2. fold material and knead for 30-45 seconds until a homogenous, pink colored mixture
3. allow 5-7 minutes for setting

Question 2

FCC Prep Design

Answer 2

1. functional cusp bevel: 1.5 mm
2. chamfer finish line: 0.5 mm
3. morphological occlusal reduction
   * *functional cusp: 1.5 mm
   * *central fossa: 1.5 mm
   * *non-functional cusp: 1.5 mm
4. axial reduction: 1-1.5 mm

Question 3

Prep Sequence

Answer 3

1. occlusal
2. functional bevel
3. axial
4. proximal
5. margination
6. detail/finish

Question 4

Step 1, Occlusal reduction

Answer 4

depth cuts: typically follow the inclines of the tooth, consider morphology of planned restoration

1. non-functional cusp area: 1.5 mm
2. functional cusp area: 1.5 mm
3. central fossa needs to be reduced as well

Question 5

Functional cusp bevel

Answer 5

1. not having a functional cusp bevel leads to over-contoured crown and eccentric interferences
2. realigns the functional cusps wit the opposing central groove
3. provides uniform 1.5 mm reduction

Question 6

Step 2, Axial wall reduction: depth cuts

Answer 6

depth cuts: half depth of the bur, consider taper and path of draw

• *adequate dimension of reduction: 1-1.5 mm for metal
• *guiding point is margin (finish line) area: 0.5 mm

1. too much reduction: increased metal thickness, over tapered
2. too little reduction: decreased metal thickness, over-contoured restoration

Question 7

Step 2, Axial wall reduction: taper

Answer 7

total occlusal convergence

1. ideally: 6 degrees (6-16 degree acceptable)
2. consider anatomical forms: don’t follow labial slope!!

Question 8

Step 2, Axial wall reduction: path of draw

Answer 8

1. parallel to long axis of tooth
2. consider path of insertion from adjacent teeth
3. determine path of draw before starting axial wall prep
4. be careful of undercuts…there shouldn’t be any!!

Question 9

Step 3, Proximal Wall Reduction

Answer 9

1. swing motion reduction

2. round off the corners after proximal contacts are open

Question 10

Step 5, Margination

Answer 10

1. refine the finish line

2. do a CHAMFER=0.5 mm

Question 11

Step 6, Detail/Finish

Answer 11

1. verify occlusal clearance
2. verify morphologic reduction
3. labial surface curvature
4. round all line angles
5. verify occlusal clearance

Question 12

How to verify occlusal clearance

Answer 12

1. visualize with eyes
2. with ball burnisher or flexible clearance guide
3. putty matrix and perio probe
4. bite registration
5. occlusal thickness of provisional