Dental inlays and onlays: a middle ground between a filling and a crown

Inlays and onlays are custom-made tooth restorations that repair moderate decay or damage without replacing the entire tooth. Learn when your dentist might recommend one and how they compare to fillings and crowns.

Medically reviewed by Dr. Jose, DDS — August 7, 2026

What Are Inlays and Onlays?

Inlays and onlays are custom-made restorations that sit between a simple filling and a full crown in terms of complexity and tooth coverage. Both are crafted in a dental lab to fit the exact shape and size of your tooth.

An inlay fits snugly inside the grooves and pits of your tooth, replacing only the decayed or damaged portion. An onlay does the same job but also covers one or more cusps—the pointed ridges on the chewing surface of your tooth. Think of an inlay as a puzzle piece that fills a hole; an onlay covers a bit more territory.

When Does Your Dentist Recommend One?

Your dentist typically suggests an inlay or onlay when:

• The decay or damage is too large for a standard filling to handle reliably
• Your tooth still has enough healthy structure that a full crown would be overkill
• You want a restoration that will last longer than a filling in that spot
• The damaged area is confined to the chewing surface or between cusps, not requiring complete crown coverage

This decision is always your dentist’s call based on what they see during an examination and on X-rays. Self-diagnosing isn’t possible—only a licensed dentist can assess whether your tooth needs this level of restoration.

Materials

Inlays and onlays are typically made from:

• Ceramic or porcelain – tooth-colored, durable, and blends in naturally
• Composite resin – also tooth-colored and less expensive than ceramic, though it may wear slightly faster
• Gold – extremely durable and long-lasting, though less common for cosmetic reasons

Your dentist will discuss which material suits your tooth’s location, your bite, and your preferences.

The Process

Creating an inlay or onlay usually takes two visits:

1. First appointment: Your dentist removes the decayed or damaged part, shapes the remaining tooth, and takes a mold or digital scan. A temporary restoration protects your tooth until the permanent one is ready.
2. Second appointment: The lab-made inlay or onlay is cemented into place and adjusted to fit your bite perfectly.

The multi-step process means inlays and onlays take longer than fillings, but the precision often pays off in durability.

Durability and Care

With proper care, inlays and onlays can last many years. To keep yours healthy:

• Brush twice daily with a soft-bristled toothbrush
• Floss daily, especially around the edges where the restoration meets your natural tooth
• Avoid chewing on hard objects like ice, hard candy, or fingernails
• Attend regular dental checkups so your dentist can monitor the restoration and your overall tooth health

If you notice any looseness, sensitivity, or damage, contact your dentist—catching problems early can prevent more costly treatment later.

How They Compare

Fillings are faster and less expensive but may not last as long for larger cavities. Crowns cover the entire tooth and are recommended when damage is extensive or the tooth is weakened. Inlays and onlays offer a middle path: they’re more durable than fillings and more conservative than crowns, making them ideal for moderate-sized problems.

For more on how cavities form and what leads to needing restorations, see our guide on cavities. If you’re curious about full-crown treatment, our crown guide explains that process in detail.

How MediMouth Helps

If your dentist has recommended an inlay or onlay, a MediMouth provider can explain the procedure, show you material samples, and answer your questions about cost and timeline. You can also ask about getting a second opinion if you’d like another dentist to review your X-rays and treatment plan. We’re here to help you find a trusted provider and understand your options.

This guide is educational information from MediMouth. It is not a diagnosis or a treatment plan, and it isn't a substitute for seeing a licensed dentist.