Overview: Find ideal design parameters, including occlusal clearance and axial wall reduction, for various crown and bridge restoration materials.
Restoration Material Specifications
Incorrect margin design or insufficient preparation can lead to refabrications. Use the following specifications to determine the necessary clearance for each material type.
Zirconia Restoration Requirements
Zirconia Monolithic: Requires a 0.65mm minimum buffer, 1.5mm ideal occlusal clearance, and 1.2mm axial wall reduction with a 1.0mm shoulder or chamfer margin.
Zirconia Translucent Aesthetic: Requires 0.7mm (Anterior) or 0.9mm (Posterior) minimum buffer, 1.5mm ideal occlusal clearance, and 1.2mm axial wall reduction with a 1.0mm shoulder or chamfer margin.
Porcelain Fused to Zirconia (PFZ): Requires a 0.65mm minimum buffer, 2.0mm ideal occlusal clearance, and 1.5mm axial wall reduction with a 1.0mm shoulder or chamfer margin.
Metal and Porcelain Restoration Requirements
Porcelain Fused to Metal (PFM): Requires a 0.5-0.6mm minimum buffer, 2.0mm ideal occlusal clearance, and 1.5mm axial wall reduction with a 1.0mm shoulder or chamfer margin.
Full Metal Crown: Requires a 0.5-0.6mm minimum buffer, 1.0mm ideal occlusal clearance, and 1.0mm axial wall reduction with a 0.5mm shoulder or chamfer margin.
Emax (Lithium Disilicate) Requirements
Emax (Lithium Disilicate): Requires 0.9mm (Anterior) or 1.1mm (Posterior) minimum buffer, 1.5mm ideal occlusal clearance, and 1.2mm axial wall reduction with a 1.0mm shoulder or chamfer margin.
Layered Emax: Requires 0.9mm (Anterior) or 1.1mm (Posterior) minimum buffer plus 1mm for all porcelain surfaces, 2.0mm ideal occlusal clearance, and 1.2mm axial wall reduction with a 1.0mm shoulder or chamfer margin.
Emax Veneer: Requires a 1.0mm minimum buffer, 0.6mm ideal axial wall reduction, and a 0.5mm chamfer margin.
| Materials | Minimum + 0.1mm buffer | Ideal Occlusal Clearance | Ideal Axial Wall Reduction | Margin Type | Margin Thickness |
| Zirconia Monolithic | 0.65mm | 1.5mm | 1.2mm | Shoulder or Chamfer | 1.0mm |
| Zirconia Translucent Aesthetic | 0.7mm Ant/0.9mm Post | 1.5mm | 1.2mm | Shoulder or Chamfer | 1.0mm |
| PFZ - Porcelain Fused to Zirconia | 0.65mm* | 2.0mm | 1.5mm | Shoulder or Chamfer | 1.0mm |
| PFM - Porcelain Fused to Metal | 0.5-0.6mm* | 2.0mm | 1.5mm | Shoulder or Chamfer | 1.0mm |
| Full Metal Crown | 0.5-0.6mm | 1.0mm | 1.0mm | Shoulder or Chamfer | 0.5mm |
| Emax - Lithium Disilicate | 0.9mm Ant/1.1mm Post | 1.5mm | 1.2mm | Shoulder or Chamfer | 1.0mm |
| Layered Emax - Layered Lithium Disilicate | 0.9mm Ant/1.1mm Post (+1mm for all porcelain surfaces) |
2.0mm | 1.2mm | Shoulder or Chamfer | 1.0mm |
| Emax Veneer | 1.0mm | 0.6mm | Chamfer | 0.5mm |
Technical Notes for PFMs
By default, Porcelain Fused to Metal (PFM) restorations are designed for full porcelain coverage. If the occlusal clearance is less than 1.5mm, the design may require metal occlusal or metal lingual surfaces. Confirm these requirements during the case review process.