Do you have a cavity? If it is small, your dentist may fill it. If the cavity is deep inside the tooth or fractured, you may need a crown. Inlays and onlays are used when a filling isn't enough, but a crown is too extensive.
Inlays are sometimes used to replace a small amount of lost tooth structure due to decay. Inlays fit inside the tooth. They are often used to repair tooth damage on chewing surfaces.
An onlay is similar to an inlay but is more extensive. In addition to covering the inside of the tooth, an onlay also covers the tooth cusp (pointed or raised surfaces) to protect the tooth.
Your dentist may recommend an onlay when more than 50% of the chewing surface is damaged.
The main difference is an inlay fills in smaller spaces, but an onlay covers a larger area, including one or more tooth cusps.
Inlays and onlays are commonly crafted from porcelain, gold, or composite resin. Porcelain is a popular choice as the inlay or onlay can be made to match the color of your natural teeth.
Inlay and onlays cost more than fillings. An onlay may cost more than an inlay because of the amount of restoration required. Your costs will depend on:
The type of material the dentist uses (porcelain, composite resin, or gold)
How much decay or damage the tooth has. If the decay is deep or covers a sizeable area, the procedure may cost more.
The dentist's years of professional experience
Where the tooth is located
Your dentist will numb the area with a local anesthetic to alleviate any pain. Talk with your dentist about any concerns you may have about the procedure.
Getting an inlay or onlay usually requires two dental appointments.
If you're interested in learning more about dental inlays and onlays, and what treatments and materials are best for you, talk with your dentist.