Inlays and Onlays

An inlay or an onlay is a solid ceramic repair that sits between a filling and a crown. An inlay fits inside the cusps. An onlay covers one or more cusps. At Pearl32 Dentistry and Wellness in Laguna Hills, we design them from a digital scan and mill them in house, so most are finished in one visit. They keep more of your own tooth than a crown does. They are not the answer for a tooth with very little structure left.

What is an inlay or an onlay?

A single piece of ceramic, made to fit a prepared cavity and bonded in. An inlay sits within the walls of the tooth, like a filling shaped outside the mouth. An onlay does the same and also covers one or more cusps, which protects them from splitting. Both are milled from a ceramic block that is stronger and more wear resistant than composite. Because they are shaped outside the mouth, the contact with the neighboring tooth and the anatomy of the chewing surface can be made accurately. Dentists sometimes call an onlay a partial crown, which describes it well.

When do we choose one over a filling or a crown?

When the cavity is too wide for composite but the tooth still has healthy walls. A useful line is about half the width of the chewing surface. Past that, a direct filling flexes and its margins fail sooner. A cracked cusp, a cusp already lost, or a large old amalgam with a fracture line are all reasons to cover the tooth. A crown is chosen instead when the walls are already gone, when a tooth has had root canal treatment and needs full coverage, or when appearance calls for it. The difference matters, because a crown removes tooth structure around the whole circumference.

How is it made in one visit?

Scan, design, mill, bond, in roughly two hours. We numb the tooth, remove the decay or the old filling, and shape the surfaces so the ceramic has an even path to seat. A digital intraoral scanner records the preparation, the opposing teeth and the bite, with no impression tray. We design the restoration on screen, matching the contacts and the cusp shape. The in house milling unit cuts it from a ceramic block while you wait, usually in 10 to 20 minutes. It is then polished or glazed, tried in, checked for fit and bite, and bonded with resin cement. No temporary and no second appointment.

How long do inlays and onlays last?

Commonly 10 to 15 years, and often longer on a tooth that is otherwise healthy. Ceramic resists wear and does not shrink as it sets, which is why the margins hold. What shortens that life is grinding, a crack in the root below the restoration, or new decay at the margin from plaque. We check margins at every recall visit with an explorer and x-rays. If you grind at night, a guard protects the work, and we can make one from the same scan. Nothing bonded to a tooth is permanent, so catching a margin early means repairing rather than remaking.

What will an inlay or onlay not do?

It will not save a tooth that has too little structure left. If the walls are gone below the gum, or the tooth is cracked through the floor of the pulp chamber, an onlay bonds to nothing reliable. Those teeth need a crown with a build up, root canal treatment, crown lengthening, or in some cases an implant. When the x-ray leaves a question about the root, we take a 3D cone beam scan and look before we prepare anything. An onlay also will not change the color of your other teeth. We match the ceramic to the shade you have now, so whiten first if you plan to.

What do inlays and onlays cost?

We quote them in writing after an examination, itemized, before any preparation begins. We do not publish prices, because the size of the repair, the tooth involved and the condition of the nerve all change the plan. An x-ray and a look at the tooth come first, then the quote, then your decision.

We are in network with most major PPO plans and Delta Dental HMO, and we verify benefits before booking. For larger treatment plans, outside payment plans are available through CareCredit, Cherry, Sunbit and Happen Bank (formerly LendingClub). Third party financing is available and the practice is not the creditor. We are at 24022 Calle De La Plata, Suite 450, Laguna Hills, CA 92653, Monday to Friday, 8 AM to 5 PM, with free street parking and free spaces behind the building.

Questions people ask about inlays and Onlays

Is an onlay the same as a partial crown?

In practice, yes. Both describe a ceramic restoration that covers one or more cusps without wrapping the whole tooth. The terms overlap in dentistry and in insurance coding, which is why we write the specific tooth and surfaces on your quote. What matters clinically is how much of the tooth is covered and how much healthy structure stays untouched.

Does it really take only one visit?

For most patients, yes. The scanner and the milling unit are both in the office, so the ceramic is cut while you wait. Plan on about two hours from numbing to bonding. A few cases still go to a laboratory, for example when a front tooth needs an unusually demanding shade match. We tell you which route your tooth takes before we begin.

Will the ceramic wear the opposing tooth?

Modern ceramics, polished properly, wear opposing enamel at a rate close to enamel itself. What causes damage is a rough surface, so we polish or glaze every restoration and check it at recall visits. Grinding is the larger factor, and a night guard protects both the onlay and the natural teeth. Tell us if you wake with sore jaw muscles.

Can an onlay be placed after root canal treatment?

Sometimes, when enough wall thickness remains. A back tooth that has had root canal treatment usually needs cusp coverage, and an onlay can provide it if the walls are intact. If the access cavity has left thin walls, a crown is the sounder repair. We assess the remaining structure after removing the temporary filling and tell you what we find before preparing the tooth.

What if the onlay comes loose?

Call (949) 830-0074 and bring it with you if it came out whole. We hold same day emergency slots on weekdays, and we are open Monday to Friday, 8 AM to 5 PM. If the bond failed but the ceramic and the tooth are intact, it can often be cleaned and rebonded. If the tooth underneath has decayed, we discuss a new restoration and show you the x-ray first.

This page is general information, not a diagnosis. What is right for you can only be decided after an examination.