What’s the Difference Between Dental Inlays and Onlays Restorations?

Most people are familiar with traditional dental fillings and crowns (“caps”.) But not many individuals have heard of an alternative to these treatments, known as a dental inlays and onlays.

What is are inlays and onlays, and what are the advantages of requesting this treatment in lieu of a standard restoration?


Larger Than a Filling, Smaller Than a Crown

Fillings are ideal when a tooth has a small cavity. But when tooth decay or fractures extend deeper into teeth, trying to patch it up with a filling only places the tooth at a higher risk of fracturing and cracking during everyday use. At this point, the majority of general and cosmetic dentists progress to a full coverage dental crown that protects the entire tooth, even if there is significant healthy structure remaining.

Sometimes fillings are not effective, but crowns are too aggressive than what’s truly necessary. It’s at this point where dental inlays and onlays come into play. An inlay or onlay offers greater protection and durability than a large filling but is significantly less invasive than a full coverage “cap” which requires reshaping of the tooth entirely. Yet, many dentists do not offer inlays and onlays in their practice.

Filling in the Fissures/Valleys and Grooves

Inlays are sometimes called “lab made fillings” because of their purpose and design process. An inlay essentially fills in the valleys and hollows inside of a tooth, as long as the cusps around it are still intact. It’s almost like a large filling, except more durable than a standard composite or amalgam (metal) restoration.

Because inlays restore such a large portion of teeth, they’re made in a lab like a crown. First, the compromised tooth structure is removed, then an impression or digital scan is taken. The impression/scan is transferred to the lab, where a technician designs it by hand or has it milled electronically. Because it’s made from a solid piece of ceramic or zirconia, the inlay is extremely durable and acts to strengthen the tooth, rather than pose a risk to the enamel that’s left.

Covering the Cusps and Biting Edges

In contrast, onlays cover the cusps and ridges (or biting edges) of teeth, rebuilding enamel that’s been chipped or broken off. When it comes to recreating the shape of compromised teeth, an onlay is more like a traditional crown, except it does not cover the full tooth surface.

Onlays are sometimes called “three-quarter crowns” because of their ability to cover such a large area, without encompassing the entire tooth. As such, they’re more conservative than traditional crowns, allowing you to preserve as much healthy, natural tooth structure as possible.

Experience the Difference of Conservative Dentistry

Kois Center graduates provide a wide variety of restorative choices aside from those found in traditional dental practices across the United States. To learn more about what a minimally invasive dental onlay or inlay can do for your smile, contact a Kois Center dentist in your area today.