Repair of Chipped Metal Fused Ceramic Crown

PFM crowns metal with a porcelain coating which is meant to simulate the form of the tooth. Chips usually form when the outer porcelain fractures or breaks away, most often as a result of excessive bite force, trauma, or gradual wear and tear. This damages the metal substructure underneath, which can make the crown look unnatural and even cause sensitivity or discomfort in some cases.

Repairing a chipped PFM crown serves to restore its structural integrity, aesthetics, and functionality. If you leave a chipped crown untreated, it can cause several problems:

• Sensitivity or discomfort from the bare metal.
• Uncomfortable chewing, especially on hard foods.
• Aesthetic issues, when the impacted crown is a front tooth.
• Risk of more damage, leading to a more expensive treatments down the line.

Not every chipped crown needs to be fully replaced. Repair is often the preferred choice for patients with:

• Minor to moderate chipping that does not threaten the structural base of the crown.
• Discomfort or sensitivity with no visible signs of damage, but the underlying tooth has not suffered any damage.
• Aesthetic considerations, especially for anterior crowns.
• Seeking cost-effective treatment options due to financial constraints.

The best way to repair a chipped PFM crown depends on the size of the chip and the position of the break. Common techniques include:

• Composite Bonding: The chipped area is coated with a tooth-colored composite resin, sculpted to recreate the contour of the crown and then hardened with a curing light. Perfect for small chips, and can be done in one appointment.
• Porcelain Repair Kit: The kits include special adhesives and ceramic repair materials that bond with the existing porcelain. They are slightly more technique-sensitive but provide a better aesthetic match for larger or more visible chips.
• Crown Reglazing: Very small chips can also be addressed by smoothing out the surface with a thin layer of glaze, restoring a polished shine. That is a quick fix and noninvasive, but not for deeper damage.
• Crown Replacement: If the chip is sizable, or if the metal substructure has ruptured, the crown may need to be entirely replaced. This is the option that takes the most time and cost invests, but gives the most reliable long-time result.

• Examination and Diagnosis: The dentist will first visually inspect the crown and take X-rays to assess the damage and the best way forward.
• Surface Preparation: The chipped area is thoroughly cleaned and then roughened using etching agents or mechanical tools to create a surface suitable for bonding.
• With composite bonding, a bonding agent is placed and then the resin is placed.
• A unique primer and ceramic material are then used for porcelain repair which is cured by light.
• Shaping and Polishing: The dentist shapes the material to reflect the original contour of the crown, and polishes it to achieve a smooth, natural look.
• Final Evaluation: The repaired crown is checked for bite alignment, comfort, and aesthetic appeal. Adjustments are made as necessary.

• Returns full function and natural morphology.
• Compared to replacing the crown, minimally invasive.
• Cost effective for minor to moderate damage.
• Turn-around time is short; procedure is often completed in a single appointment.
• Extends the lifespan of the original crown.

Repairing a chipped PFM crown has several advantages over full replacement:

• Less expensive, which benefits most patients.
• Allows the preservation of the original crown structure, lessening the need for further dental work.
• Quicker results: Repairs can be completed in a shorter amount of time.
• Lesser pain, with minimal/no anesthesia required.

The longevity of a repaired crown depends on various factors such as:

• Material – Higher quality composite or ceramic materials tend to last longer.
• Patient habits – Staying off hard foods and good oral hygiene helps preserve the repair.
• Location of the crown -  Molars are subject to higher stresses than teeth at the front of the mouth, and the lifespan of a repair will be reduced.

• Composite bonding – 30 to 60 minutes.
• Porcelain restoration – Can take 1 to 2 appointments as it cures and gets layered in.
• Crown replacement – At least 2 visits required: one for preparation and impressions, one for fitting new crown.

In India, a chipped PFM crown can be repaired at the price of:

• Composite Bonding – Rs 2,000 to Rs 5,000.
• Porcelain Repair Kit — ₹3,000 to ₹7,000.
• Crown Replacement — ₹3,000 to ₹25,000.

While crown repairs are very safe, some risks that come with crown repairs include:

• Poor bonding resulting in additional chipping.
• Discoloration, particularly if done hastily.
• Sensitivity,if the repair doesn’t seal to exposed metal.
• Partial repair, which may later need replacing.

• Repaired areas are not permanent and may require maintenance in the future.
• Not as strong as new crown.
• Minor aesthetic differences between repair material and original porcelain.

Alternatives may include, based on the situation:

• Complete Crown Replacement - Best for more complex or multiple fractures.
• Zirconia Crowns – Aesthetic, durable, and metal-free.
• Dental Veneers – Ideal for small cosmetic fixes on front teeth.

Some care after the repairing is important to ensure the crown lasts:

• Steer clear of anything hard or sticky that could chip.
• Brush and floss your teeth regularly.
• It’s important to go for regular dental check-ups and also to take care of the crown.
• Wear a night guard if you have bruxism (teeth grinding).