Inlays and Onlays: What are They And When are They Needed?

You may have heard the terms “inlays” and “onlays” from your dentist and wondered what they mean. Simply stated, they are a dental care treatment to repair cavities, tooth decay, wear from bite force, tooth trauma, and small fractures. 

Inlays and onlays are similar to filings and crowns, but differ in the following ways: 

• Fillings are used for small cavities and are best for the sides of teeth.
• Inlays are used in place of fillings when only a small amount of tooth structure has been lost to decay. Inlays are used when a cavity requires stronger materials to fortify the tooth.
• Onlays are for substantial cavities that don’t cover the entire tooth surface.
• Crowns are used when there is deeper decay or larger tooth fractures, and tooth reshaping is needed. 

What is an inlay?

An inlay replaces decayed tooth enamel. Once your cavity is removed, your dentist places your inlay on the chewing surface of your tooth. Your inlay is custom designed to fit the area between tooth cusps. Inlays are created using an imprint of the affected areas and are manufactured in a dental lab. This means they provide greater strength because they fit your teeth perfectly. Inlays are also better at preserving as much of your natural tooth as possible.

Inlays are made from tooth colored ceramic, porcelain or a composite material that is stronger than traditional fillings. Porcelain in particular can be perfectly matched to the color of your teeth. Porcelain naturally bonds to teeth. This bonding process improves the strength of your tooth.

Inlays vs. fillings 

There are many benefits of inlays compared to fillings:

• Inlays preserve as much of your natural tooth as possible. 
• With natural tooth structure in place, it’s easier to clean your teeth.
• Inlays work better than fillings for larger cavities in the center of the tooth.
• Porcelain inlays are more stable than amalgam or composite fillings which can expand and contract, causing cracks. This makes fillings ideal for the sides of teeth, while inlays are more durable for chewing surfaces.
• Porcelain inlays are a biocompatible material. They strengthen teeth and can handle 75% more chewing force.
• Inlays are custom-made by using an impression to fit perfectly to your teeth. 

Inlays have a few disadvantages in comparison to fillings. When choosing between the two, you and your dentist should take the following into account:

• Fillings can be placed in one visit. Lab-manufactured inlays usually require two visits.
• Fillings are less expensive. 
• In the event of damage, repairing an inlays is more difficult.

What is an onlay?

Onlays are recommended when a cavity is too big to fill, but too small for a Crown. Onlays are also called partial crowns. This is because they cover a portion of the tooth. Onlays are placed to preserve natural tooth structure. 

Onlays are custom manufactured in a lab. Our onlays are made of porcelain from an exact imprint of your teeth. The porcelain naturally bonds with your tooth to add strength. The porcelain used in both inlays and onlays is perfectly color-matched to your surrounding teeth. 

Onlays vs. crowns

Onlays and crowns differ in size and location. Crowns are an excellent restorative solution when significant wear or decay has occurred. They either extend down the sides of your tooth or cover the tooth. Onlays are smalle. They fit over the biting surface of your tooth and extend to cover the cusps. 

Dental professionals often recommend an onlay to: 

• Preserve as much of your natural tooth as possible.
• Provide additional strength to your tooth. 

If you’re not sure whether you need inlays, onlays, crowns or fillings, we encourage you to reach out to a dental professional for a consultation! Alternatively, click the link below if you’d like to learn more about the services and procedures involving inlays and onlays! 

Dr. Sarah Frahm