A dental inlay is a custom-made restoration that fits inside the grooves of a tooth, covering the area between the cusps (the raised points on the biting surface). It works like a filling but is fabricated outside the mouth, typically in a dental lab, and then cemented into place. Inlays are used when a cavity or area of damage is too large or too deep for a standard filling but not extensive enough to require a full crown.
How an Inlay Differs From a Filling, Onlay, or Crown
The easiest way to understand an inlay is to see where it sits on the spectrum of dental restorations. A standard filling is placed directly into a cavity while the material is still soft, then hardened in the mouth. An inlay, by contrast, is made to precise measurements and bonded in as a single, solid piece. This bonding process can actually improve the strength of the remaining tooth and create a tighter seal than a traditional filling.
The distinction between an inlay and an onlay comes down to cusps. An inlay sits entirely within the cusps of your tooth, filling the space between them. An onlay extends over one or more cusps, covering a larger portion of the biting surface. Think of an inlay as fitting inside the tooth like a puzzle piece, while an onlay drapes over part of the top.
A crown, on the other hand, caps the entire visible portion of the tooth. Dentists generally choose an inlay or onlay when the damage is confined to a specific area and the cusps and edges of the tooth are still strong and intact. Crowns are reserved for teeth that are extensively decayed or damaged. Because inlays preserve more natural tooth structure, they’re considered a more conservative approach.
Materials Used for Dental Inlays
Inlays were historically made only of gold, which is extremely durable and wears at a rate similar to natural enamel. Gold inlays are still available, but most patients today request tooth-colored options. The two main alternatives are ceramic (porcelain) and special dental composite resin. Porcelain inlays closely match the appearance of natural teeth and resist staining well. Composite resin inlays are also tooth-colored and can be a slightly less expensive option, though they may not last quite as long as porcelain in some cases.
Beyond appearance, tooth-colored inlays offer a functional advantage: they’re bonded directly to the tooth structure with adhesive cement, which helps reinforce the remaining tooth. Gold inlays are cemented in place but rely more on the precision of their fit than on adhesive bonding.
What the Procedure Looks Like
Getting an inlay typically requires two appointments. At the first visit, your dentist numbs the area with a local anesthetic and removes the decayed or damaged portion of the tooth using a dental drill. If there’s a crack or chip, the surface is smoothed out to create a clean, even shape for the inlay to sit in. Then an impression of the prepared tooth is taken and sent to a dental lab, where the inlay is custom-fabricated. Before you leave, a temporary seal is placed over the tooth to protect it from bacteria while you wait.
At the second appointment, the temporary seal is removed and the finished inlay is checked for fit, then cemented permanently into place. This step is relatively quick. Some dentists may schedule a follow-up to confirm the inlay is fitting properly and your bite feels normal. Offices equipped with same-day milling technology can sometimes complete the entire process in a single visit, though the two-appointment approach remains more common.
Recovery and What to Expect Afterward
Recovery from an inlay placement is straightforward. You’ll be numb for a few hours after the procedure, so avoid chewing on that side until the sensation returns. Minor discomfort and sensitivity to hot or cold are common in the first few days. Sticking to soft foods like yogurt, mashed potatoes, and smoothies during that initial period helps avoid putting unnecessary stress on the restoration.
During the first week, it’s best to avoid hard and sticky foods. You can gradually reintroduce your normal diet as the tooth settles. Most people experience a complete recovery within two weeks. If sensitivity or discomfort persists beyond that, it may indicate the inlay needs a minor adjustment to your bite.
How Long Inlays Last
Inlays are built for durability. A prospective study published in the European Journal of Dentistry tracked composite resin inlays for up to nine years and found an 85% success rate at the nine-year mark, with zero failures in the first six years. Other research has shown even better numbers: one 12-year study found a failure rate of only 12%, and another reported that roughly 80% of inlays were still functioning well after a full decade. Porcelain and gold inlays generally last at least as long, and often longer.
The factors that most influence how long an inlay lasts include the health of the surrounding tooth structure, the quality of the seal at the margins where the inlay meets the tooth, and your bite forces. Teeth that still have strong, healthy enamel supported by solid underlying structure give inlays the best foundation. Over time, the thin line of cement at the edge of the restoration is the most vulnerable point, since cement wears faster than the inlay material itself. Good oral hygiene and regular dental checkups help catch any marginal breakdown early.
Cost and Insurance Coverage
Dental inlays generally cost between $650 and $1,200 per tooth, with an average around $900. The price varies depending on the material chosen, the size and location of the restoration, and your geographic area. Porcelain and composite inlays tend to fall in a similar range, while gold can vary based on current metal prices.
Because inlays treat decay or trauma, dental insurance typically covers them as a major restorative procedure. With a reasonably good insurance plan, your out-of-pocket cost may drop to between $10 and $50 for a gold inlay, or $40 to $100 for a porcelain or composite version. Coverage varies significantly between plans, so checking your specific benefits before the procedure gives you a clearer picture of what you’ll actually pay.