Onlays Vs. Crowns: What’s The Difference?

Missing, broken, or decayed teeth are not only a source of physical pain and embarrassment, but they can also be harmful to your health. People with missing teeth can experience chronic headaches and are at higher risk for oral infections that are liable to spread throughout the body and cause a variety of potentially serious health issues.

There are many ways to prevent tooth loss and tooth decay, such as regular brushing and flossing and maintaining a healthy diet, but what do you do if you already have missing, broken, or decayed teeth?

Fortunately, if you are one of the millions of people in America today who are experiencing issues with your teeth, there are solutions for you. However, action is required before the problem progresses and becomes more serious.

What to Do About Broken, Decayed, or Missing Teeth

There are a few different options for someone looking to replace or mend a tooth. For teeth with lesser damage or with cavities that have been identified early enough, a filling or an inlay should suffice, but in cases where there is extensive damage or the decay is significant, you’re likely to need either an onlay or a crown.

But what’s the difference between an onlay and a crown, and which option is the best for you? Read on to learn more about the distinctions between the two restorative dental solutions, so you can get your self-confidence back and start eating and smiling like you used to.


Onlays are a dental procedure intended to replace missing tooth structure. They’re similar to an inlay, in which a piece of material is bonded onto the tooth to restore a compromised section, with the only difference being that an onlay offers a greater amount of coverage and can replace one or more cusps of the tooth. A cusp is the section of the tooth that aids in the chewing of your food and can be found on both your back teeth and your canines.


Crowns are used to restore teeth with significant damage or decay. When a large section, or even all, of the visible tooth is missing, but the root remains healthy, a crown can serve to bring the tooth back to its normal appearance and functionality.

Materials Used in Onlays and Crowns 


For many years, the material used for onlays and crowns was gold. In fact, gold is believed to have been used in restorative dentistry for thousands of years. The reason for this is that gold is a hard material that is malleable and is almost impervious to corrosion. Dentists often create a gold alloy, combining the material with other metals, such as nickel and palladium, in order to make the onlay or crown both stronger and more affordable.

However, in recent years other materials, such as ceramic and porcelain, have gained popularity for their ability to better imitate the natural look of a tooth. These materials can also be used as an alternative for people with metal allergies.


Porcelain is a material often used in dentistry because of its ability to imitate the look of a natural tooth. The type of porcelain used in restorative dentistry is often made from quartz, feldspar, and kaolin. Because porcelain is perhaps the weakest of materials used in onlays and crowns, it is sometimes bonded to precious metals in order to increase its durability. The downside of bonded porcelain, however, is that the appearance of the precious metal can sometimes take away from the porcelain’s more natural look.


Ceramic is a stronger material for onlays and crowns than porcelain, but not quite as strong as bonded porcelain. In some instances, an onlay or crown made of pressed ceramic and topped with porcelain is used in order to create a highly durable onlay or crown that doesn’t have the less-than-natural-looking drawback of bonded porcelain.


Resin onlays and crowns offer a more affordable solution to tooth restoration. While resin can be made to match the exact color of your existing teeth, the material can wear down more easily than others.

The Procedure

When you go to your dentist to receive your onlay or crown, you can expect the following:

  • Your dentist will give you a local anesthetic in order to numb the pain and ensure that the procedure goes as smoothly as possible
  • The damaged area of your tooth will be removed in preparation for the onlay or crown replacement
  • A mold of your tooth will then be made in order to create a custom-fitted onlay or crown
  • Some dentists may be able to offer an onlay or crown replacement on the same day. Otherwise, you will have a temporary onlay or crown fitted which will be removed and replaced once the permanent onlay or crown has been created.
  • Once the permanent onlay or crown has been placed, the dentist will ensure that it fits well and then make any adjustments if necessary.

The Difference Between an Onlay and a Crow

If you haven’t already guessed it, the difference between an onlay and a crown is pretty small. Crown and onlay differences are solely based on the extent of the damage to, or decay of, the tooth. If your tooth is somewhat intact but requires replacing one or more cusps, an onlay is what your dentist will likely recommend. If the tooth has extensive damage or decay or is entirely missing, save for an otherwise healthy root, you’re likely going to need a crown.

Going to the dentist can be an anxiety-ridden affair for many people. In fact, it’s frequently listed among the biggest fears that people have. But waiting to schedule a dental appointment out of fear can result in far bigger issues down the road. If you think you may be in need of an onlay, a crown, or any other type of dental restoration, don’t hesitate to contact your dentist.