Onlay vs Crown: When an Inlay or Onlay Makes More Sense Than a Crown

Onlays and inlays are conservative dental restorations that preserve more natural tooth structure than crowns, while still offering strength and protection. Crowns cover the entire tooth when more extensive damage is present.

At a Glance:

• Onlays and inlays are conservative restorations.

• Crowns are full coverage, thus more removal of natural tooth.

• CEREC technology makes onlays faster and easier today.

• Dr. Freking herself would choose an onlay “if it were her own tooth.”

• The right choice depends on how much healthy tooth remains.

What Are Inlays and Onlays (vs Crowns)?

Inlays fit inside the chewing surface of a tooth, between the cusps. Onlays extend further, covering one or more cusps. Crowns cover the whole visible portion of the tooth when the structure is too weak or damaged.

Inlays and onlays are sometimes called the “middle ground” between a small filling and a full crown.

• Inlay: Think of it as a puzzle piece that sits neatly inside the grooves of your tooth.

• Onlay: Covers those grooves and one or more cusps (the raised points you feel when you run your tongue over your molars).

• Crown: Encases the whole visible tooth, essentially acting as a cap when damage is too extensive for a partial restoration.

Dentists often use the terms inlay and onlay together because they’re made from the same durable materials (usually resin/ceramic blends or fully ceramic) and placed in a very similar way. The difference is simply in how much of the tooth surface they restore.

At Park Slope Dentistry Seventh Avenue, we often recommend inlays or onlays when a simple filling isn’t strong enough, but a full crown would mean removing more healthy tooth than necessary. 

If too much of the tooth is already lost or weakened, that’s when a crown becomes the safer option.

Why Dentists Value Onlays & Inlays

Onlays and inlays preserve more natural tooth structure than crowns, which can help extend the lifespan of the tooth.

For many dentists, onlays and inlays have long been considered a kind of “labor of love.” 

• They take more time and technical precision than crowns

• They’ve historically been less productive financially

• They often demanded extra adjustments once they came back from the lab

But despite those hurdles, dentists like Dr. Angelique Freking have always valued them because they do what matters most: protect as much of your natural tooth as possible.

Dr. Freking explains that before investing in modern chairside technology, placing onlays or inlays often came with frustrations. Temporary restorations could break, and the seating process required lots of adjustments. All of that made them harder to deliver than crowns, even though they were often the better treatment choice.

Today, thanks to CEREC digital dentistry, those barriers are largely gone. With in-office scanning and milling, onlays and inlays can be created and placed in a single visit. The result: more precision, fewer remakes, and the ability to confidently recommend onlays when they’re the right choice. 

That’s why Dr. Freking says, “If it were my own tooth, I’d choose an onlay.”

Experience same day dentistry right here in Park Slope!

Onlay vs Crown. Which Should You Choose?

Dentists recommend onlays or inlays when enough healthy tooth remains to support the restoration. A crown is advised when the tooth is too compromised and needs full coverage.

Choosing between an onlay and a crown often comes down to how much natural structure your tooth still has:

• Onlays/Inlays: Best for moderate decay or damage. They cover only the affected part of the tooth, preserving as much enamel as possible.

• Crowns: Needed when the tooth is too weak or fractured to be restored conservatively, or if a posterior tooth has been root canaled. A crown fully covers the tooth to restore strength and function.

Other factors also matter, such as whether the tooth is in the back or front of your mouth, the daily bite force required, and the risk of fracture over time.

Onlays and inlays appeal to many patients (and dentists) because they feel like a more conservative, “tooth-friendly” option. 

The Procedure: How They Are Made & Placed

Inlays and onlays are made either indirectly in a dental lab or chairside using CEREC, then bonded to the tooth. 

Here’s how the process works:

1. Preparation. We numb the area and carefully remove any decay or old filling. Much less healthy tooth structure is removed for an onlay or inlay than for a crown.

2. Impression or scan. Traditionally, impressions were sent to a lab, but with modern CEREC scanning, we make a precise digital model right in the office.

3. Fabrication. The restoration is either milled chairside from a ceramic block (same-day solution) or crafted in a dental lab.

4. Fit and bonding. Once ready, the onlay, inlay, or crown is checked for fit, bonded securely, and polished for a natural look.

Why this matters: Chairside digital dentistry means fewer remakes, fewer adjustments, and no waiting while in a temporary restoration, which can dislodge and ruin your day.

Durability, Care & Life Expectancy

Well-made inlays, onlays, and crowns can last 10–15 years or longer with proper care, depending on the material and daily habits.

The lifespan of these restorations depends on several factors:

Materials

Ceramic and porcelain onlays blend naturally with your teeth and are highly durable. Composite is a more affordable option, though it may wear a bit sooner. 

Gold remains the “gold standard” for longevity and fit, but it’s far less lifelike and has become increasingly expensive, which is why it’s used less often today.

In our office, Dr. Freking and her team often use a hybrid composite–ceramic material, which combines the best of both worlds: the strength of ceramic with the repairability and conservation of composite. 

This approach allows us to remove less healthy tooth structure during treatment and easily repair the restoration later if a new cavity develops nearby. With full ceramic onlays, that kind of repair isn’t possible, since new composite can’t bond effectively to ceramic.

Biting forces 

Clenching, grinding, or chewing very hard foods can shorten the life of any restoration.

Margins and fit 

A precise fit reduces the risk of decay at the edges, which is why modern digital scanning is so valuable.

How to Make Them Last

• Brush and floss every day, just like your natural teeth.

• Avoid chewing ice, hard candies, or non-food items.

• Use a night guard if you grind your teeth.

• Stay consistent with your regular dental exams and cleanings.

Park Slope Dentistry Seventh Avenue: Onlays, Inlays, and Crowns Done Right

With today’s digital technology, patients can enjoy the precision and strength of inlays and onlays without the delays and complications that used to make them harder to deliver. Crowns remain an excellent solution when a tooth is too damaged, but whenever preservation is possible, we aim for the most conservative, long-lasting option.

If you’re considering restoration in Brooklyn, let us evaluate whether an onlay, inlay, or crown is right for your tooth.

Book your appointment online or call 718-550-1284 today.

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