Inlays & Onlays

Inlays and onlays are conservative indirect restorations designed to repair damaged or decayed teeth, most commonly premolars and molars. An inlay fits within the cusps of a tooth and restores the central chewing surface, while an onlay extends over one or more cusps and replaces a larger portion of the tooth. Both restorations are custom fabricated to precisely match the prepared tooth anatomy and occlusion.

These restorations are typically made from strong, tooth-colored materials that mimic natural enamel and provide excellent stain resistance. Because they are bonded to the tooth, inlays and onlays can restore function while preserving more healthy tooth structure than a full crown. Their strength and fit make them a predictable option for moderate tooth damage that does not yet require full coverage.

Inlays and onlays are recommended when a tooth has damage or decay that is too extensive for a conventional filling but not severe enough to justify a full-coverage crown. They are an ideal middle-ground solution when the remaining tooth structure is sound enough to be preserved, allowing the restoration to reinforce and protect the tooth. Dentists commonly choose these restorations to replace large or failing fillings, to repair fractured cusps, or to treat areas of recurrent decay while minimizing tooth reduction.

Choosing an inlay or onlay helps maintain natural tooth anatomy and can reduce the need for more invasive treatment in the future. When tooth structure can be preserved, patients often experience better long-term outcomes and simpler future restorative options. A clinical evaluation and X-rays determine whether an inlay or onlay is the most appropriate choice for a given tooth.

A direct filling is placed and shaped inside the mouth during a single visit and is best for small to moderate areas of decay, while inlays and onlays are fabricated outside the mouth for a precise fit. Compared with crowns, which cover the entire visible portion of a tooth, onlays and inlays preserve more healthy tooth structure because they only restore the damaged areas. This conservative approach reduces the amount of enamel and dentin that must be removed during preparation.

In terms of strength and longevity, laboratory-made inlays and onlays are often more durable and wear-resistant than large direct fillings, and they can be a good alternative to crowns when full coverage is unnecessary. The choice among these options depends on the extent of damage, the tooth’s structural integrity, and functional demands such as bite forces. Your dentist will discuss the pros and cons of each option and recommend the most appropriate restoration for your needs.

Inlays and onlays are commonly fabricated from porcelain or ceramic, composite resin, and sometimes metal alloys such as gold. Porcelain and ceramic restorations are favored for posterior teeth when aesthetics are important because they can be matched to the natural tooth color and resist staining over time. Gold and metal alloys remain excellent choices for strength and longevity, particularly in areas where appearance is less of a concern.

Advances in dental ceramics provide a good balance of aesthetics and durability for most patients, and they are often recommended when a natural look is desired. Your dentist will consider factors such as the location of the tooth, the size of the restoration, bite forces, and esthetic goals when recommending a material. At Royersford Dental Health, we evaluate these variables carefully to select the material that best meets each patient’s functional and cosmetic needs.

The process typically begins with a thorough exam and removal of decay or old filling material, followed by shaping the tooth to receive the restoration. An impression or a digital scan is taken to capture the exact contours of the prepared tooth and opposing bite, and a temporary restoration may be placed while the laboratory fabricates the custom inlay or onlay. If your dental office has chairside CAD/CAM technology, the restoration can sometimes be designed and milled in a single visit for same-day placement.

At the placement appointment, the custom restoration is tried in for fit and occlusion, adjusted as needed, and then bonded to the prepared tooth with a strong resin. Proper bonding technique is essential to achieve a tight seal and optimal strength, so the dentist will follow precise protocols for cleaning, etching, and cementation. Once bonded, the restoration is polished and checked against your bite to ensure comfort and function.

Inlays and onlays are very durable when properly designed and bonded, and they can significantly strengthen a damaged tooth, with some studies showing strength increases up to 75 percent. Longevity depends on material, oral hygiene, bite forces, and regular dental care; many well-made ceramic or gold restorations last for a decade or more, and some last several decades with good maintenance. Regular dental visits allow the dentist to monitor the restoration and address any wear or marginal changes early.

Good home care, including daily brushing and flossing, reduces the risk of recurrent decay at the margins of the restoration and contributes to longevity. Avoiding habits such as chewing on ice or hard objects and wearing a night guard if you grind your teeth can also help protect the restoration. If sensitivity, roughness, or a change in bite occurs, contact your dentist so the restoration can be evaluated and adjusted if needed.

Bruxism, or teeth grinding and clenching, places increased stress on all dental restorations and can shorten the lifespan of inlays and onlays if left unaddressed. In many cases an onlay or inlay can still be used successfully for patients who grind, provided that protective measures such as a custom night guard are instituted to limit damaging forces. The restoration design and material selection can be adjusted to provide greater resistance to fracture for patients with heavy occlusal loads.

Before placing a restoration in a patient with bruxism, the dentist will evaluate occlusion and the extent of wear and may recommend occlusal therapy to stabilize the bite. Ongoing monitoring is important to identify signs of excessive wear or marginal breakdown early. With appropriate preventive care and occlusal protection, inlays and onlays remain a viable option for many patients who grind or clench their teeth.

Caring for an inlay or onlay is similar to caring for a natural tooth and involves regular brushing with fluoride toothpaste, daily flossing, and routine dental checkups. Paying attention to the margins where the restoration meets the tooth is important because plaque accumulation in these areas can lead to recurrent decay if not properly managed. Professional cleanings and examinations allow your dentist to assess the restoration’s condition and detect any early problems.

It is also advisable to avoid chewing very hard foods or nonfood items that could chip or dislodge the restoration, and to use a night guard if you have a tendency to grind. If you notice any sensitivity, roughness, or a change in your bite after placement, contact the dental office for an evaluation. Prompt attention to minor issues can prevent more extensive treatment later.

Minor surface chips or small fractures may sometimes be smoothed and repaired using composite materials, but significant damage generally requires replacement of the restoration. The feasibility of repair depends on the extent of the defect, the underlying tooth structure, and the material of the restoration. A thorough clinical and radiographic evaluation helps determine whether a repair is safe and likely to be long-lasting or whether replacement is the more predictable option.

If replacement is indicated, the dentist will remove the damaged restoration, assess the tooth for any additional decay or structural compromise, and proceed with a new inlay or onlay or an alternative restoration if needed. Regular follow-up care and early intervention for minor problems increase the chances of repairing rather than replacing restorations. Your dentist will explain the advantages and limitations of repair versus replacement for your specific situation.

Common short-term effects include mild sensitivity after placement as the tooth adjusts to the new restoration, but this typically resolves within a few days to weeks. Other potential complications include marginal leakage, debonding, fracture of the restoration, or recurrent decay if oral hygiene is inadequate. Proper case selection, precise bonding technique, and careful occlusal adjustment reduce the likelihood of many of these issues.

Long-term risks are minimized through regular dental examinations, where the dentist can detect early signs of wear, looseness, or decay and intervene promptly. If you experience persistent discomfort, a change in your bite, or a loose restoration, contact your dentist for an evaluation. With appropriate technique and maintenance, inlays and onlays are a predictable and effective option for restoring compromised posterior teeth.