Standard Process: PFM Crown Preparation

By Cebu Dental Implants & Oral Care Specialists

Porcelain-Fused-to-Metal (PFM) crowns remain a reliable restorative option for patients requiring both strength and aesthetic appeal. Proper tooth preparation is essential to achieve long-lasting results, accurate fit, and optimal esthetics. Below is the standard protocol for PFM crown preparation, covering both anterior and posterior teeth.

1. Understanding PFM Crowns

A PFM crown combines the durability of metal with the beauty of porcelain, making it ideal for restoring teeth in both aesthetic and functional zones. The underlying metal provides strength, while the porcelain overlay mimics natural enamel translucency.

2. Key Principles of Crown Preparation

• Preserve tooth structure: Remove only what’s necessary for proper crown thickness.

• Ensure adequate reduction: Allow sufficient space for both metal and porcelain layers without over-tapering.

• Smooth margins: To achieve accurate fit and minimize microleakage.

• Rounded internal angles: To prevent stress concentration on the crown and the tooth.

3. PFM Crown Preparation Design

Anterior Teeth

• Incisal Reduction: 2.0 mm
  Allows space for porcelain layering and natural esthetics.

• Labial Reduction: 1.5 mm
  Provides adequate room for metal and porcelain without over-contouring.

• Lingual Reduction: 0.5–1.0 mm
  Preserves tooth structure while accommodating metal support.

• Cervical Margin: 0.5 mm metal chamfer
  Ensures a smooth and defined finish line for accurate crown fit.

Posterior Teeth

• Functional Cusp Reduction: 2.5 mm
  Creates space for porcelain in areas exposed to chewing stress.

• Non-functional Cusp Reduction: 2.0 mm
  Maintains proper occlusal form while supporting the crown’s structure.

• Axial Reduction: 1.5 mm
  Provides uniform space for restoration materials and retention.

• Occlusal Reduction: 0.8–1.0 mm at the central groove
  Ensures proper occlusal clearance and metal support.

• Finish Line: 0.5 mm metal chamfer
  Allows precise adaptation and prevents marginal gaps.

4. Clinical Tips for Optimal Results

• Use depth-cutting burs to maintain consistent reduction.

• Evaluate clearance using silicone putty or fleximeter strips.

• Round all sharp internal angles to prevent crown fracture.

• Verify occlusal clearance before taking the final impression.

5. Conclusion

A precise crown preparation determines the longevity, comfort, and esthetics of a PFM crown. Following these evidence-based measurements ensures a well-adapted restoration that harmonizes function, strength, and beauty.

For professional dental restorations and expert PFM crown fabrication, visit:
Cebu Dental Implants & Oral Care Clinic
Your trusted partner in advanced restorative dentistry
www.cebudentalimplants.com

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