The Short Answer
Inlays and onlays repair a back tooth that has too much damage for a filling but not enough to need a crown. They replace only the damaged part, so you keep more of your natural tooth than you would with a crown. They also hold up better than a large filling. When most of the tooth is broken down, a crown is usually the better choice.
At Precision Dentistry of Olympia, Dr. Eric Xu follows a biomimetic approach to restoring teeth: keep drilling to a minimum and save as much healthy tooth as possible. That’s why he often recommends an inlay or onlay instead of a crown.
Inlays and Onlays vs. Fillings and Crowns
Inlays and onlays are custom restorations for back teeth. They’re made outside the mouth from porcelain, ceramic, composite resin, or gold, then bonded to the tooth. An inlay sits inside the cusps, the raised points on the chewing surface. An onlay covers one or more cusps, which is why it’s also called a partial crown. Our post on the difference between inlays and onlays goes into more detail.
| Filling | Inlay or onlay | Crown | |
|---|---|---|---|
| What it covers | Fills the cavity left after decay is removed | Replaces the damaged part of the chewing surface, inside the cusps (inlay) or over them (onlay) | Covers the whole visible tooth |
| Best for | Small to moderate cavities | Moderate damage, like a large cavity or a broken cusp | Teeth that need full coverage |
The Benefits of Inlays and Onlays
More of your natural tooth stays
To fit a dental crown, the tooth has to be shaped down on every side. An inlay or onlay only replaces what’s damaged, so the healthy walls of the tooth stay where they are.
Stronger than a large filling
A large filling is more likely to crack or come loose under the force of chewing. An inlay or onlay is made in one solid piece, usually porcelain or ceramic, and bonded to the tooth, which helps reinforce what’s left.
Easier on your gums
The edges of an onlay usually sit above the gumline, where they’re easy to keep clean. A crown’s edges often sit at or just below the gumline, and in some cases that can lead to gum inflammation.
Less sensitivity afterward
Shaping a tooth for a crown removes a lot of enamel, and the tooth can be sensitive afterward, especially if the temporary crown comes loose. Because an inlay or onlay needs less shaping, there’s less chance of that. Some sensitivity to hot and cold for a short time is still normal.
They match your tooth and resist stains
Porcelain and ceramic are matched to the shade of your tooth, so they’re hard to tell apart from the rest of it. They also hold their color better than a filling does.
When a Crown Is the Better Choice
An inlay or onlay needs enough healthy tooth around it to bond to. A crown is usually the better choice when:
- Most of the tooth is broken down or decayed
- A crack runs through the tooth
- The tooth has had root canal treatment and needs full protection
- A large filling has failed and there isn’t much tooth left around it
Not every cracked or root-canal-treated tooth needs a crown, though. If the walls of the tooth are still strong, an onlay can sometimes cover it instead. Dr. Xu checks the tooth with digital X-rays and an intraoral camera, so you’ll see the damage on screen before deciding. If a crown makes more sense, our post on how dental crowns protect damaged teeth covers that option.
What Our Patients Say
Dr. Xu is an exceptional dentist. I moved to Olympia a few months ago and needed an emergency extraction. He performed the procedure completely painlessly, which immediately gave me confidence in his skill and professionalism…
Dr. Xu is an exceptional dentist. I moved to Olympia a few months ago and needed an emergency extraction. He performed the procedure completely painlessly, which immediately gave me confidence in his skill and professionalism. Afterward, he created a comprehensive treatment plan, and I’ve since returned three more times for fillings. Every visit has been an outstanding experience. I especially appreciated that he used two different filling materials—a medicated base that continues to help protect and heal the tooth, followed by a durable outer composite filling. Taking the extra time to do what’s best for the long-term health of the tooth really impressed me…
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I had an excellent experience with Dr. Xu and the entire team at Precision Dentistry in Olympia. Dr. Xu was honest, straightforward, and thorough when explaining my treatment options…
I had an excellent experience with Dr. Xu and the entire team at Precision Dentistry in Olympia. Dr. Xu was honest, straightforward, and thorough when explaining my treatment options. I especially appreciated that he took the time to discuss different ways to approach my dental work, including breaking treatments into stages so I could make the most of my dental insurance benefits. The entire staff is incredibly friendly, welcoming, and helpful. From the moment I walked in, I felt like I was being treated with genuine care and respect rather than simply being another patient. I highly recommend Dr. Xu and the team at Precision Dentistry to anyone looking for quality dental care, honest advice, and a staff that truly cares about their patients. I’m very glad I chose them!
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Both Dr. Xu and his staff are incredibly helpful! He explained everything he did during my dental procedure, and his front desk staff, Danielle, was very helpful about my insurance…
Both Dr. Xu and his staff are incredibly helpful! He explained everything he did during my dental procedure, and his front desk staff, Danielle, was very helpful about my insurance. These people are HERE for their patients! As I face a fair amount of dental work, I’ll definitely be a return patient.
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Frequently Asked Questions
How long do inlays and onlays last?
With good care, they can last more than 10 years. How long yours lasts depends on the material, how much tooth is left around it, and your habits. Grinding your teeth or chewing ice and other hard things can shorten it. If you grind at night, ask us about a night guard.
Do inlays and onlays cost less than a crown?
They can. They use less material and less chair time, so they may cost less. Call our office for current pricing. If you're paying out of pocket without insurance or a membership plan, we take 5% off.
Can you replace an old silver filling with an inlay or onlay?
Yes. Replacing a large, worn-out filling is one of the main reasons we use them. If the old filling is small, a tooth-colored composite filling may be all you need.
How do I take care of an inlay or onlay?
The same way you care for the rest of your teeth: brush twice a day, floss daily, and keep your regular cleanings. The restoration itself can't decay, but the tooth around its edges still can. Let us know if it ever feels loose or your bite feels different.
Talk to Us About Inlays and Onlays in Olympia
If you’ve been told you need a crown and want to know whether an onlay could work instead, call (360) 995-0025 or request an appointment. You can also read more about inlays and onlays in Olympia on our service page. We’re open Monday and Wednesday through Friday, 8 a.m. to 5 p.m., at 2728 Westmoor Court SW, Suite D, Olympia, WA 98502, and see patients from Olympia, Lacey, Tumwater, and nearby communities.