Fixed Criteria

Fixed Criteria

1. PFM (anterior prep)Incisal Edge Reduction:

2mm (1.5-2.5 mm)

Lingual Reduction (cingulum area)1.25-1.5mm (1.00-2.00mm)

Facial-Proximal Axial Reduction:

1.2-1.3mm both planes (1.0-1.5mm)Lingual Wall Axial Reduction:axial depth half the depth of chamfer bur (slightly heavier/lighter)Retention and Resistance:6-10 degrees, 2-3mm lingual wall (10-15, no undercuts)

Shoulder Finish line and angle:90 degrees and 0.5mm suprag. (at the tissue level 0.75mm suprag.)

Chamfer Finish Line:0.0-0.5mm supragin. (0.5 subgin. -0.75mm supragin.)

Shoulder-Chamfer Blend:M - just lingual to contact, D at the contact (M, D less than 1mm buccal-lingual)Preparation on Long Axis or Tooth:Centered, cusps tips centered (minor tilt or lean)

2. PFM (posterior)-criteria is basically the same with a few exceptions

Shoulder Finish Line and angle:120 degrees and 0.5mm supragin. (at tissue level 0.75 mm)

Chamfer Finish Line:0.5mm supragin. (0.25 subgin. -1.0mm supragin.)

Functional Bevel Placement:2.5mm occl. apical height, correct angulation and reduction (slight under or over reduction)Non-functional Bevel Placement:2.5-3.0mm occl. apical height, correct angulation and reduction (slight under or over reduction)3. FVCOcclusal Reduction:

1.5mm (1.00-2.00 mm)

Retention and Resistance:6-10 degrees, 3-4mm lingual wall (10-15, no undercuts)Axial Reduction:tooth morphology maintained (slight change in morphology)

Functional Bevel Placement:correct angulation/reduction (slightly under/over)

Non-functional Bevel Placement:see above

Chamfer Finish Line:0.5mm supragin. (at tissue level -0.75mm supragin.)

depth of bur (slightly shallow/heavy) Preparation on Long Axis or Tooth:Centered, cusps tips centered (minor tilt or lean)4. Crown (Maxillary)Occlusal Reduction:1.5mm (L) 1.0mm (B) (1.25-2.00mm (L) within 0.5mm (B))

Retention and Resistance:6-10 degrees, adequate lingual wall (10-15, no undercuts)Retention and Resistance (boxes):1.5mm axial depth and 90 degrees lingual exit angles(within 0.3mm, 90-100)Axial Reduction:tooth morphology maintained (slight change in morphology)

Lingual Finish Line:half of depth of chamfer bur, 1.00mm below box and 0.5mm supragingivalFunctional Bevel Placement:correct angulation/reduction (slightly under/over)

Non-functional Bevel Placement:correct angulation/reduction, 0.5mm (slightly under/over, 0.3mm)Buccal Angles of Exit135 with 0.75mm clearance (>90 but 90 but