PFM Crown vs Zirconia: Which is Better?

Introduction to Dental Crowns

Dental crowns play a crucial role in modern dentistry by restoring the shape, size, and function of damaged teeth. They are often used to protect a weak tooth from breaking, to restore an already broken tooth, or to cover and support a tooth with a large filling. 

Crowns are also used to hold a dental bridge in place, cover misshaped or severely discolored teeth, and cover dental implants. These versatile applications make dental crowns an essential part of dental restoration and cosmetic dentistry.

Understanding PFM and Zirconia Crowns

What is a PFM Crown?

PFM stands for porcelain-fused-to-metal. A PFM crown consists of a metal framework covered with a layer of porcelain ceramic material. The metal provides strength and durability, while the porcelain layer mimics the natural appearance of a tooth. This combination makes PFM crowns a popular choice for dental restorations, as they offer both strength and a reasonable aesthetic appeal.

What is a Zirconia Crown?

Zirconia crowns are made from zirconium dioxide, a type of ceramic known for its exceptional strength and durability. Unlike PFM crowns, zirconia crowns are metal-free, which can be advantageous for patients with metal allergies. Zirconia crowns are also highly biocompatible and provide a natural look, closely resembling the appearance of real teeth. This makes them a popular choice for both front and back teeth restorations.

Advantages of PFM Crowns

Natural Appearance

PFM crowns can closely mimic the color and translucency of natural teeth due to their porcelain coating. This makes them a good choice for restoring front teeth, where aesthetics are particularly important.

Strength and Durability

The metal framework beneath the porcelain layer provides significant strength and durability. This makes PFM crowns capable of withstanding the forces of biting and chewing, ensuring a long-lasting restoration.

Cost-Effectiveness

PFM crowns are often more affordable compared to metal-free alternatives like zirconia crowns. The combination of metal and porcelain materials makes them a cost-effective option for dental restorations.

Drawbacks of PFM Crowns

Limited Natural Look

One of the main drawbacks of PFM crowns is that the underlying metal can sometimes show through the porcelain at the gum line, giving a greyish tint. This can affect the overall natural appearance, especially when smiling or talking.

Allergic Reactions

The metal used in PFM crowns can cause allergic reactions or sensitivity in some patients. Those with metal allergies may experience discomfort or adverse reactions, making PFM crowns unsuitable for them.

Potential for Gum Recession

To place a PFM crown, a portion of the natural tooth structure must be removed. Over time, this can lead to gum recession, exposing the metal base of the crown and further compromising the aesthetic appeal.

Susceptibility to Chipping and Breaking

While PFM crowns are strong, the porcelain layer can still chip or break under pressure from biting, chewing, or grinding. If the porcelain chips, the underlying metal may become visible, reducing the crown's aesthetic value.

Advantages of Zirconia Crowns

Exceptional Strength and Durability

Zirconia crowns are renowned for their exceptional strength and durability. Zirconia is a very hard material, which makes these crowns highly resistant to the wear and tear of daily biting and chewing. This strength also means that zirconia crowns are less likely to crack or break, providing a long-lasting solution for tooth restoration.

Natural Aesthetic Appeal

Zirconia crowns offer a highly natural look that closely resembles the appearance of real teeth. They can be color-matched to your natural teeth and provide a translucency similar to that of natural enamel. This makes zirconia crowns an excellent choice for both front and back teeth, ensuring a seamless and attractive smile.

Long-Lasting

A tooth restoration with a zirconia crown can last many years, often up to a lifetime with proper care. This longevity makes zirconia crowns a cost-effective investment in your dental health, as they provide durable protection and aesthetic appeal over the long term.

Non-Toxic and Safe

Zirconia is a biocompatible material, meaning it is not likely to cause adverse reactions in the body. Zirconia crowns are metal-free, making them a safe option for patients with metal allergies or sensitivities. Their non-toxic nature ensures that they can be used safely in a wide range of dental patients.

Stain Resistance

Zirconia crowns are resistant to staining from foods, drinks, and other substances that typically discolor natural teeth. This stain resistance helps maintain the crown's natural appearance over time, reducing the need for whitening treatments and other maintenance.

Drawbacks of Zirconia Crowns

Wear on Opposing Teeth

The hardness of zirconia crowns, while advantageous for durability, can also be a drawback. Their toughness can cause significant wear on the opposing teeth, especially if there are any imperfections in the bite. This wear can lead to issues such as increased tooth sensitivity and the need for additional dental treatments.

Higher Cost

Zirconia crowns are generally more expensive than other types of dental crowns, including PFM crowns. The higher cost is due to the advanced materials and technology required to create zirconia crowns. Factors like the location of the dental practice and the complexity of the case can also influence the price, making zirconia crowns a less accessible option for some patients.

Risk of Brittle Fracture

Although zirconia crowns are highly durable, they can sometimes be prone to brittle fractures under extreme force or impact. This brittleness can lead to cracks or breaks that may require repair or replacement of the crown. However, such incidents are relatively rare and often associated with extreme conditions.

Types of Zirconia Crowns and Bridges

Layered Zirconia

Layered zirconia crowns consist of a zirconia base layered with porcelain. This combination enhances the crown's aesthetic appeal, making it suitable for front teeth where appearance is crucial. The layering process allows for a highly natural look that mimics the translucency and color of real teeth.

High Translucency Zirconia

High translucency zirconia crowns are designed to provide a more natural appearance, closely matching the look of natural enamel. These crowns are ideal for front teeth restorations, where aesthetics are particularly important. They combine strength with a highly lifelike appearance, making them a popular choice for visible areas of the mouth.

Monolithic Zirconia

Monolithic zirconia crowns are made from a single block of zirconia, providing exceptional strength and durability. These crowns are typically used for back teeth restorations, where the forces of biting and chewing are greatest. Monolithic zirconia crowns are less likely to chip or break, offering a reliable solution for long-lasting dental restoration.

Low-Fusing Zirconia

Low-fusing zirconia is specifically used for covering dental implants. These crowns adapt well to titanium implants, providing a secure and aesthetic restoration. Low-fusing zirconia offers the perfect balance of strength and appearance, making it a preferred choice for implant-supported restorations.

Full Contour Zirconia Crowns (FCZ)

Full contour zirconia crowns (FCZ) cover the entire tooth and offer exceptional strength and crack resistance. These crowns are made without layered porcelain, which reduces the risk of chipping. FCZ crowns are ideal for back teeth, where durability is essential, and they provide a natural look while maintaining high strength.

Zirconia Crown Bridges

A zirconia crown bridge is composed of multiple connected crowns, replacing several missing teeth simultaneously. Types of zirconia bridges include:

1. All-on-Four Zirconia Bridge: Replaces all missing teeth in an arch using four implants.
2. Long-Span Zirconia Bridge: Covers multiple teeth or large gaps.
3. Full Arch Zirconia Bridge: Also known as roundhouse dental bridges, these replace the entire upper or lower arch of teeth.
4. Hybrid Zirconia Bridge: Combines implants with an artificial bridge structure, offering a stable and practical solution for replacing multiple teeth or entire dental arches.

Zirconia bridges provide excellent strength, durability, and a natural appearance, making them ideal for extensive dental restorations.

Choosing Between PFM and Zirconia Crowns

Factors to Consider

When deciding between PFM and zirconia crowns, several factors should be taken into account:

1. Aesthetics: Zirconia crowns offer a more natural look without the risk of a greyish tint at the gum line, making them ideal for front teeth.
2. Durability: Zirconia crowns are generally more durable and resistant to wear and tear compared to PFM crowns.
3. Cost: PFM crowns are usually more affordable than zirconia crowns, which might be a crucial factor for budget-conscious patients.
4. Biocompatibility: Zirconia crowns are metal-free and less likely to cause allergic reactions, making them suitable for patients with metal sensitivities.
5. Functionality: For patients who grind their teeth or have a strong bite, the strength of zirconia crowns can be beneficial, though it may cause wear on opposing teeth.

Dentist Recommendations

Your dentist will consider these factors, along with your specific dental needs and oral health, to recommend the best type of crown for you. The decision will be based on:

1. Tooth Location: Front teeth often benefit from the aesthetic advantages of zirconia, while back teeth may require the strength and durability of either zirconia or PFM.
2. Oral Health: The condition of your gums and surrounding teeth can influence the choice of crown material.
3. Personal Preferences: Your preferences regarding cost, appearance, and longevity will also play a significant role in the decision-making process.

Summary of Findings

When it comes to choosing between PFM and zirconia crowns, both have their unique advantages and drawbacks:

1. PFM Crowns: Offer a balance between cost and functionality with a reasonable natural appearance. They are strong and durable but may cause allergic reactions and show a greyish tint at the gum line. They are also prone to chipping and require more tooth reduction.
2. Zirconia Crowns: Known for their exceptional strength, durability, and highly natural appearance. They are more biocompatible and resistant to stains but come at a higher cost and can cause wear on opposing teeth. The risk of brittle fracture is minimal but should still be considered.

If you're considering dental crowns and need guidance on which type is best for you, schedule a consultation with your dentist. They can provide personalized advice based on your oral health and aesthetic preferences. Whether you opt for PFM or zirconia crowns, the right choice will help restore your smile and improve your dental health.