Tooth Preparation Guide & Checklist

Full Coverage Restorations

Anterior Crown Preparation

1. Minimum 1.0mm Facial Reduction

2. 1.5-2.0 mm incisal reduction

3. 1.5mm lingual contact clearance

4. 1.0mm reduction at gingival with a Butt joint margin

5. Keep internal line angles rounded. Use a football-shaped finishing bur

---

3-Unit Bridge Restorations

3-Unit Bridge Preparation

1. 1.5mm axial reduction

2. 1.5-2mm incisal reduction

3. 1.0mm reduction at gingival margin with a Butt joint margin

4. Keep internal line angles rounded

---

Veneers

Uniform Facial Preparation

A medium grit, round-ended, diamond bur is used to remove a uniform thickness of facial enamel by joining the depth-cut grooves.

Depth cuts of 0.6mm to 0.8mm

For additional masking capabilities or layering techniques, further reduction my be necessary.

Incisal Preparation

The diamond bur is angled to bevel back the incisal edge.

1.0mm to 1.5mm incisal reduction.

Chamfer Margins

Correct preparation of the chamfer margins interproximally allows the appropriate bulk of porcelain.

---

3-Unit Bridge Preparation

1. Rounded internal line angles

2. 1.5mm to 2.0mm of occlusal reduction

3. 1.5mm axial reduction

1. 1.0mm reduction at the gingival margin with a butt joint margin

2. 1.5mm axial reduction

3. 1.5mm to 2.0mm occlusal reduction

4. Rounded internal line angles

---

Posterior Crown Preparation

1. A Flat-ended tapered diamond bur is utilized to establish a butt joint margin.

2. Rounded internal line angles.

3. 1.5mm to 2.0mm occlusal reduction

4. 1.5mm axial reduction

5. 1.0mm reduction at the gingival margin

Conventional Cementation Preparation

1. Occlusal reduction of at least 2.0mm in contact area

2. Coronal length at least 4.0mm and taper between 4* and 8* degrees

3. Shoulder preparation of at least 1.0mm proximal reduction

---

Inlay Preparation

1. Rounded internal line angles with Butt joint margin

2. 1.0mm to 1.5mm wide gingival floor

3. 1.5mm depth at isthmus

4. 1.5mm-2.0mm isthmus width

Onlay Preparation

1. Rounded internal line angles with Butt joint margin

2. 1.0mm to 1.5mm wide gingival floor

3. 1.5mm-2.0mm isthmus width

---

Zirconium Oxide/Lithium Disilicate/All-Ceramic Prep Checklist

1. Create a uniform and distinct 360 degree chamfer margin (0.7mm-1.0mm whenever possible) with an appropriately sized 856 diamond bur (Axis Dental Corp). The most commonly sizes are -014 for very small teeth, -016 for most anteriors, and -018 or -021 in the posterior.

   Note: Some clinicians find it easier to prepare a uniform 360 modified shoulder preparation (1.2mm) utilizing a 846KR-016 diamond bur (Axis Dental Corp)

2. 1.5 (circumferential) axial reduction is ideal

3. 2.0mm posterior (occlusal) reduction is ideal for aesthetics and function for any all ceramic restorations. 1.5mm would be the minimum clearance needed. Minimal axial wall height remaining after preparation should be 3-4mm.

4. 1.8mm-2mm incisal reduction

5. 1.0mm minimum (whenever possible) anatomic (anterior) lingual reduction. Use a 379-021 or 379-023 football diamond bur to create a concave surface for optimal functional harmony.

6. Smooth anatomic contours with rounded line angles throughout.

7. Avoid any proximal boxes or grooves.

8. Aesthetic cores (as well as compomer, resin ionomer or composite resin block-out) should be placed at the chair during the preparation appointment prior to impression taking.

9. Remember to prepare all teeth utilizing multi-plane reduction for the creation of a restoration with natural, anatomic contouring and optimal aesthetics.