Dental Crowns Overview

Overview

• Full metal crowns are a type of dental restoration that completely covers the visible portion of a tooth.
• They are made of various metals, often alloys, to achieve strength and durability.
• They are used to restore severely damaged or decayed teeth, or to improve the aesthetics of a tooth.

Materials

• Gold alloys: Historically significant, gold alloys offer excellent biocompatibility and long-term durability. However, they can be expensive and may require more tooth structure removal than other options.
• Porcelain-fused-to-metal (PFM): A popular choice for years, PFMs combine the strength of a metal substructure with the esthetic qualities of porcelain. This allows for natural-looking restorations but with the potential for metal discoloration showing through if not carefully placed.
• Non-precious metal alloys: Nickel-chromium and other alloys offer good strength and are often more cost-effective than gold. Allergic reactions are possible with some of these materials.
• All-ceramic crowns: Replacing the metal substructure with porcelain or zirconia allows for highly esthetic restorations. All-ceramic restorations are less prone to metal-related issues like discoloration, but may require a more substantial amount of tooth structure removal due to the reduced inherent strength when compared to PFM or metal.

Procedure

• Preparation: The dentist shapes the tooth to create space for the crown by removing part of the tooth structure.
• Impression: A mold of the prepared tooth is taken to create a model for the restoration.
• Crown fabrication: The lab technician crafts the crown based on the impression.
• Fitting: The completed crown is fitted to the tooth.
• Cementation: A dental adhesive is used to cement the crown in place.

Advantages

• Strength and Durability: Metal crowns are known for their ability to withstand heavy chewing forces.
• Long-lasting: When well-maintained, full metal crowns can last for many years.
• Cost-effectiveness (in some cases): Compared to all-ceramic options, they can be a more affordable restoration choice.

Disadvantages

• Metal discoloration: Metal substructures can show through over time, particularly in the gums.
• Potential for allergic reactions: Some individuals might be allergic to nickel or other metals in the alloy.
• Appearance: The metal color may not look as natural as other options.
• Potential for nerve damage: If not shaped correctly, the crown can irritate a sensitive nerve.

Alternatives

• All-ceramic crowns: Offer high aesthetics and reduce the need for metal.
• Porcelain-fused-to-metal crowns: Similar to metal, but using porcelain for the visible surface
• Resin/composite crowns: A relatively temporary solution involving filling procedures with resin.

Indications

• Severely damaged teeth: Replacing extensively broken or decayed teeth.
• High stress areas: Where biting pressure is severe, such as molars or premolars.
• Supporting damaged bridges or dentures: In severe cases of damage.
• Poorly shaped natural teeth: In certain situations, a full metal crown can be more beneficial for the overall function of the mouth.

Considerations

• Patient preferences: A discussion with the patient about their concerns, budget, and aesthetic goals is necessary.
• Oral health: Excellent oral hygiene to prevent decay around the restoration.
• Long-term maintenance: Regular dental checkups for the crown are vital for longevity.
• Cost: Full metal crowns can vary in price depending on the material and complexity of the case.