Crowns vs. Onlays vs. Inlays: What’s the Difference?

When it comes to restoring damaged teeth, you have more options today than ever before. Three of the most common choices — crowns, onlays, and inlays — are each designed to protect and strengthen your teeth, but they serve slightly different purposes.

At Edmonton Smiles, we believe that understanding your options helps you make the best decision for your oral health. In this article, we’ll break down the differences between crowns, onlays, and inlays, and explain when each one might be the right solution for your smile.

What Are Dental Crowns?

Dental crowns are full-coverage restorations that encase the entire visible portion of a tooth above the gumline. They are often used when a tooth is severely weakened, cracked, decayed, or after root canal therapy.

Key Points About Crowns:

Crowns offer full protection for teeth that are no longer strong enough to function on their own. They restore not only durability but also the natural look and feel of your smile. The following features highlight why crowns are a trusted solution for advanced tooth damage.

• Protect the entire tooth.
  Crowns cover the entire surface of a damaged tooth, sealing it off from further decay and shielding it from pressure or trauma.
• Made from materials like porcelain, ceramic, or metal.
  The material used depends on the tooth’s location and your specific needs. Porcelain and ceramic are popular for front teeth due to their natural appearance, while metal may be used for back teeth needing extra durability.
• Restore strength, shape, size, and appearance.
  Beyond protection, crowns improve the way a tooth looks and functions — restoring normal bite alignment and aesthetics.
• Often recommended when the tooth structure is heavily compromised.
  If a filling or partial restoration won’t hold, a crown provides the full support needed to prevent further damage.

When Are Crowns Used?

Crowns are recommended when a tooth is too damaged for more conservative options like fillings, inlays, or onlays. Whether due to trauma, decay, or cosmetic concerns, a crown can restore the function and appearance of your tooth.

• Extensive tooth decay.
  When a cavity is too large for a filling or inlay, a crown may be the only way to restore the tooth’s integrity.
• Large cracks or fractures.
  Cracked teeth can worsen over time. A crown holds the tooth together and prevents the crack from spreading.
• Worn-down teeth (e.g., from grinding).
  Teeth flattened from bruxism (grinding) may need crowns to rebuild height and restore normal chewing function.
• Following root canal therapy to strengthen the tooth.
  After a root canal, the tooth becomes brittle. A crown adds necessary protection and prevents future fractures.
• Cosmetic reasons (e.g., covering a misshapen or severely discolored tooth).
  Crowns offer a natural-looking solution for teeth that don’t respond well to whitening or bonding.

At Edmonton Smiles, we customize dental crowns to match your natural teeth for a seamless, functional, and beautiful result.

What Are Dental Inlays?

Inlays are a more conservative restorative option compared to crowns. They are designed to fit within the grooves of a tooth, covering only the center portion (the biting surface) without extending over the cusps (points) of the tooth.

Key Points About Inlays:

Inlays are ideal for patients who want to preserve as much of their natural tooth as possible. They provide a custom-fit solution that strengthens the tooth without unnecessary removal of healthy structure.

• Fill cavities or damage that’s too large for a regular filling but not severe enough for a crown.
• Typically made of porcelain, ceramic, or composite resin.
• Strengthen the tooth while preserving more of the natural structure.

When Are Inlays Used?

Inlays are typically used when damage is limited to the chewing surface and doesn’t involve the raised points of the tooth. They’re a strong, stable solution when a filling won’t suffice, but a crown isn’t yet needed.

• Moderate decay or damage within the tooth’s grooves.
• Replacement for large, old metal fillings.
• When a traditional filling would not provide enough support.

Because inlays are fabricated outside the mouth (usually in a dental lab) and then bonded to the tooth, they offer a stronger, longer-lasting solution compared to standard fillings.

What Are Dental Onlays?

Onlays are similar to inlays but are designed to restore a larger area of the tooth. While inlays fit within the grooves of a tooth, onlays extend over one or more of the tooth’s cusps (the raised points on the biting surface). This extra coverage allows onlays to repair teeth that have sustained more significant damage without requiring a full crown. Because of their design and function, onlays are sometimes referred to as “partial crowns.” They offer a strong, aesthetic, and conservative solution for preserving your natural tooth structure when damage goes beyond what a filling or inlay can handle.

Key Points About Onlays:

Onlays strike a balance between inlays and crowns. They allow your dentist to repair extensive damage without fully covering the tooth, preserving more of its natural structure while still providing strong protection.

• Cover both the biting surface and one or more cusps.
• Offer more protection than an inlay but less coverage than a full crown.
• Help reinforce a tooth that has suffered significant damage but still has enough healthy structure to avoid a crown.
  

When Are Onlays Used?

Onlays are recommended when tooth damage extends beyond what an inlay can repair but doesn’t yet require a crown. They’re ideal for strengthening teeth while minimizing unnecessary removal of healthy enamel.

• Damage extends beyond the grooves but doesn’t warrant a full crown.
• Large cavities that compromise the strength of a tooth.
• Restoration of broken or fractured cusps.

At Edmonton Smiles, onlays are often recommended to maximize tooth preservation while still providing durable, lasting protection.

Crowns vs. Onlays vs. Inlays: Quick Comparison

Feature	Crown	Onlay	Inlay
Coverage	Entire tooth	Biting surface + one or more cusps	Biting surface only (within grooves)
Invasiveness	Most invasive	Moderate	Least invasive
Strength Provided	Maximum protection	Strong support	Moderate support
Common Materials	Porcelain, ceramic, metal	Porcelain, ceramic, composite	Porcelain, ceramic, composite
When Used	Severely damaged teeth	Moderate to major damage	Mild to moderate decay/damage

How to Choose the Right Option

Choosing between an inlay, onlay, or crown depends on the extent of the damage, the location of the tooth, and your personal dental health goals.

At Edmonton Smiles, we thoroughly assess your tooth’s condition using high-tech imaging and careful examination. We’ll then recommend the most appropriate treatment plan to restore your tooth’s strength, function, and natural beauty.

Factors we consider include:

• How much healthy tooth structure remains.
• The amount of biting force the tooth endures.
• Your cosmetic preferences.
• Your long-term dental health.
  

Why Conservative Dentistry Matters

Whenever possible, preserving natural tooth structure is better for your long-term oral health. Inlays and onlays allow us to repair teeth conservatively without sacrificing more structure than necessary. Crowns are reserved for cases where full coverage is essential to prevent further damage or tooth loss.

At Edmonton Smiles, we follow a patient-centered, conservative approach — meaning we recommend the least invasive, most effective solution for your individual needs.

Final Thoughts: Protecting and Restoring Your Smile

Crowns, onlays, and inlays each play an important role in dental restoration. Understanding the differences helps you have informed conversations with your dentist about the best way to protect your teeth.

If you suspect you need a tooth restoration, or if you’re unsure which option is right for you, Edmonton Smiles is here to guide you.
We combine advanced technology, expert craftsmanship, and compassionate care to help you achieve a strong, healthy smile.

Schedule your consultation today at Edmonton Smiles.