Inlays and Onlays

Aesthetic and lasting repair of damaged teeth

Inlay onlay: Understanding the benefits and application in dentistry

Inlays and onlays are dental prostheses used to repair and restore damaged or decayed teeth. They are often made of ceramic and are used to reconstruct part of the tooth, the inlay being placed inside the tooth, while the onlay is placed on the surface of the tooth. The use of inlays and onlays is common in the treatment of dental caries or to replace defective fillings.

These techniques have several advantages, including their ability to preserve tooth structure and their resistance to wear. Inlays and onlays are typically customised to fit the patient’s tooth perfectly, and can also be manufactured using 3D prints to ensure a precise fit. The placement process is generally quick and simple, although regular maintenance and post-procedure considerations are necessary to ensure the durability and health of the restored teeth.

Schema Onlay Inlay overlay
Onlay Inlay overlay scheme

Key points

  • Inlays and onlays are used to repair and restore damaged teeth, particularly in the treatment of dental caries
  • These prostheses are often made of ceramic and custom-designed, sometimes with the help of 3D printing for a precise fit
  • Regular maintenance is necessary to guarantee the durability of the inlays and onlays placed and to maintain good dental health.
  • Aesthetic Restoration: Provides an aesthetically pleasing solution to damaged or decayed teeth
  • Durability: Made from durable materials like porcelain or composite resin, which resist time and wear
  • Retains more tooth structure: Compared to crowns, they require less removal of healthy tooth structure
  • Improved oral health: Helps prevent future decay of the affected tooth
  • Customization: Custom made to fit your tooth perfectly
  • Protection against bacteria: Seals the tooth and protects against bacteria
  • Comfort: Fits perfectly in the mouth, providing maximum comfort
  • Longevity: With proper care, can last for many years
Inlay et Onlay de différentes formes
Inlay and Onlay of different shapes


Inlays and onlays are known for their durability and strength. They offer a dental care solution that resists chewing and has greater longevity than traditional amalgam fillings. Thanks to their durable materials, such as ceramic or composite resin, they are a reliable option for dental repairs.


The aesthetic aspect of inlays and onlays is another important advantage to take into account. They reconstruct the damaged part of the tooth identically, thus allowing the natural appearance of the original tooth to be restored. Unlike metal amalgam fillings, they are available in materials that perfectly mimic the colour and texture of teeth, making them virtually invisible once placed.

Oral Health

Inlays and onlays also promote better oral health. Additionally, placing an inlay or onlay requires less removal of healthy tooth tissue, compared to a traditional filling or crown. This further preserves the structure and integrity of the tooth, while providing effective protection against bacteria and recurrence of cavities.

Materials Used for a Dental Inlay

Porcelain is a commonly used material for dental inlays and onlays due to its strength and natural appearance. It has a colour similar to that of natural teeth, which makes it aesthetically pleasing. In addition, it is biocompatible and resistant to wear.


Gold is another popular material for inlays and onlays because of its durability and strength. It can last more than 20 years, but its appearance is less natural than porcelain or composite resins. Although gold is a traditional choice, its visibility and high cost have led to less frequent use of this material.

Composite Resin

Composite resin is a synthetic material that is often used for inlays and onlays because of its ease of handling and ability to blend with natural tooth colour. This material offers good wear resistance and is widely used for aesthetic restorations. However, it may be more prone to wear or fading in the long term.

Glass and Ceramic

Glass and ceramic materials are becoming increasingly popular for dental inlays and onlays. They offer a combination of strength, durability and natural aesthetics. These materials are also biocompatible and pose little risk of allergies or reactions.


Amalgam is a mixture of metals, including mercury, silver, copper and zinc, used for dental fillings. However, due to concerns about the potential toxicity of mercury and the metallic appearance of fillings, the use of amalgam for inlays and onlays has declined. These days, materials like composite resin and ceramic are often favoured for their natural appearance and safety.

While it is important to choose the right material for each situation, the materials presented above offer a variety of options to meet each patient’s specific needs. The best option will depend on the aesthetic, functional and financial requirements of each situation.

Onlay sur une dent
Example of Onlay
Tooth with Onlay

Inlay Core

An Inlay Core (or simply “core”) is a prosthetic part used in dentistry to reconstruct a severely damaged tooth, often following significant decay or fracture. The Inlay Core is generally used as a support for the placement of a dental crown. The goal is to strengthen the tooth and provide a solid foundation for subsequent crown attachment. The Inlay Core is often made of metal (gold, titanium, etc.) but can also be made of composite or ceramic materials.

It generally consists of two parts:

The intraradicular part: It is sealed inside the root of the tooth, often after devitalisation.

  1. The supraradicular part: It reconstructs the coronal (visible) part of the tooth and serves as support for the crown.

  2. The supraradicular part: It reconstructs the coronal (visible) part of the tooth and serves as support for the crown.

Main differences between an Inlay and an Inlay Core

  1. Use :Inlay Core is used to rebuild and strengthen a badly damaged tooth in preparation for a crown, while Inlay is a direct restoration used to fill a cavity in a tooth.

  2. Manufacturing: Both are usually made in a laboratory, but the Inlay Core has an intraradicular component in addition to the part that replaces the tooth structure.

  3. Materials :Although both can be made from a variety of materials, gold Inlays are more common than gold Inlay Cores.

In summary, while the Inlay is a direct restoration to fill a tooth cavity, the Inlay Core is a supporting structure to prepare a damaged tooth to receive a crown.

Prise d'empreinte par un scanner 3D
Impression taking by a 3D scanner

3D fingerprint

Traditionally a mould is made to take the impression of the tooth. With technological advances, it is possible to use a 3D optical impression instead of the traditional mould. The dentist uses a 3D scanner to take a precise image of the cavity. The data is then sent to the dental laboratory where the restoration is designed and fabricated using digital equipment. This is the technique used at Bucharest British Dental Place Clinic

Installation of Temporary Inlays/Onlays

After the impression is taken, a temporary inlay/onlay can be placed on the tooth to protect the cavity until the permanent restoration is ready. This soft composite (e.g. Telio Onlay – Ivoclar Vivadent) is usually trodden into the socket and adjusted in occlusion to ensure a comfortable fit and adequate protection. At Bucharest British Dental Place Clinic, using Cerec technology, we can make an inlay or onlay in less than 1 hour.

Cementation of an Inlay/Onlay

When the restoration is ready, the dentist cements the inlay or onlay onto the tooth. The surface of the tooth and restoration is prepared with a specific adhesive solution. Cement is then applied between the tooth and the restoration to ensure a tight, strong seal. Excess cement is removed and the bite checked to ensure everything fits properly. The inlay or onlay is then polished for an aesthetically pleasing and functional result.

3D printing – CAD-CAM technology

3D printing has revolutionised the field of dentistry and the profession of dental prosthetist, particularly for dental restorations such as inlays and onlays. Thanks to this technology, it is possible to produce high-precision restorations, while preserving tooth structure and providing optimal comfort for the patient.

The process of manufacturing an inlay/onlay using 3D printing begins with the use of an intraoral scanner, which allows the area to be restored to be precisely scanned. This digital scanning not only makes the process easier, but also provides a better patient experience, as it avoids the need for traditional impressions.

Once scanned, the data is then used to model the inlay/onlay using 3D imaging software. The latter allows the restoration to be designed directly on the screen, thus offering great precision and optimal fit.

After design, the data is sent to a 3D mill, which creates the inlay/onlay from a suitable material, such as dental porcelain. 3D printing offers great flexibility in the selection of materials, allowing you to choose the one that best suits the specific needs of each patient.

Finally, the 3D milled restoration is fitted and fixed to the patient’s tooth, providing an aesthetic and functional result. Inlays/onlays made by 3D printing generally exhibit excellent fit, which contributes to the durability and comfort of the restoration.

In summary, 3D printing is an innovative and promising method for manufacturing dental inlays/onlays. It not only offers aesthetic and long-lasting results, but also increased comfort for the patient throughout the restorative process.

Bucharest British Dental Place Clinic has extensive experience with these procedures which are carried out routinely.

Intervention du chirurgien dentiste
Intervention by the dental surgeon for installation of Inlay

Dental Restoration and Alternatives

Crowns are a dental restorative solution used when the tooth is severely damaged or weakened. They cover and protect the tooth with a solid material such as ceramic or metal. Dental crowns offer a durable and aesthetic solution for patients.

Composite Resin

Composite resin is another option for restoring damaged teeth. This material is made of glass and plastic particles, which gives it great strength and an appearance similar to natural teeth. Composite resin is used to fill cavities and restore damaged teeth in a less invasive manner than crowns.

Metal, Glass and Ceramic

Besides composite resin and crowns, there are other alternatives for dental restoration. Metal fillings, such as amalgam, offer high strength and long life, although they are less aesthetic than other options. Ceramic or glass inlays and onlays are indirect restorations that repair damaged teeth while maintaining a more natural appearance. These materials are durable, resistant and offer an aesthetic appearance very close to natural teeth.

As part of dental caries treatment
Classic Filling

Conventional filling, also known as filling, is a commonly used method to treat tooth decay. This approach involves removing the decayed part of the tooth (the decay) and filling it with a restorative material. The most commonly used materials for fillings are composite resin, ceramic, and gold.

When tooth decay is shallow and only affects the enamel, the dentist may use an inlay or onlay to treat it. An inlay is a prosthesis that covers the tooth if the decay has affected an exterior wall, while an onlay is used to fill a cavity located on an interior wall. These ceramic inlays fit into the tooth like two puzzle pieces and are made in the laboratory from a cast of the tooth.


In cases where tooth decay is deeper and affects the pulp of the tooth, root canal treatment, also known as root canal treatment, may be necessary. This treatment involves removing the infected pulp from the tooth and carefully cleaning and disinfecting the root canal. Once the canal is clean and free of infection, it is filled with restorative material to seal the tooth and prevent reinfection.

Devitalisation is an important treatment option for cases of deep decay because it saves the tooth and avoids extraction. However, it is essential to see a dentist at the first signs of tooth decay to avoid more serious problems and more invasive treatments.

In summary, dental caries treatments can vary depending on the depth and location of the decay. Conventional fillings, inlays, and onlays are common treatment options for shallower cavities, while root canal treatment is used to treat deep tooth decay that affects the pulp of the tooth.

Interview and post-procedure considerations

After completing an inlay or onlay, it is important to follow a suitable maintenance plan to ensure the longevity of the restorations and the overall health of your teeth.

Interdental Cleaning

Interdental cleaning is an essential step in maintaining good dental hygiene, especially after placing an inlay or onlay. It is recommended to use a soft toothbrush to clean teeth without causing damage to inlays and onlays. Additionally, daily flossing helps remove food debris and plaque that accumulates between teeth and around restorations.

To complete the cleaning, you can also use an antibacterial mouthwash to reduce bacteria in the oral cavity and prevent infections or inflammation of the gums.

Regular Dental Appointments

Inlays and onlays are designed to last, but it is still important to visit your dentist regularly to monitor their condition. Dental check-ups allow potential problems, such as loosening or decay of restorations, to be quickly detected and treated before they become more serious.

During these appointments, your dentist may occasionally apply a local anaesthetic to perform examinations or treatments without causing pain.

By following these tips and maintaining good oral hygiene, you will contribute to the longevity of your inlays and onlays and the preservation of the health of your teeth.

Disadvantages and possible complications
Tooth sensitivity

One of the possible complications following the placement of an inlay-onlay is tooth sensitivity. After the procedure, some patients may experience increased sensitivity of the treated tooth, especially when consuming hot, cold, sweet or acidic foods. This is often due to inflammation of the dental nerve. Typically, sensitivity decreases over time, but it is important to see your dentist if it persists or increases.

Allergic reactions

The materials used for inlays and onlays are generally biocompatible and have a low allergy risk. However, some people may develop an allergic reaction to the composite resin, ceramics, or metals used in the restoration process. Symptoms of an allergic reaction include itching, redness and swelling of the gum surrounding the restored tooth. If you think you are having an allergic reaction, it is crucial to consult your dentist quickly to find a suitable solution.

In short, it is important to know the disadvantages and possible complications of inlays and onlays in order to make an informed decision for the restoration of your teeth. Although these complications are rare, it is always advisable to discuss them with your dentist before opting for this type of treatment.

Frequently asked questions
What is the difference between inlay and onlay?

Inlay and onlay are two dental restoration techniques that every dental surgeon uses routinely. Inlay is used to reconstruct the inner, invisible part of a tooth, while onlay is used when the restoration requires covering one or more cusps (tips) of the tooth or the entire biting surface.

Inlay onlay or crown: which is better?

The choice between an inlay, onlay or crown depends on the extent of the damage and the specific needs of the affected tooth. Inlays and onlays are often preferred for less complex restorations, while crowns are used for more severely damaged teeth or those requiring additional strengthening.

How much does an inlay-onlay cost?

The price of an inlay-onlay varies depending on the practitioner, the material used and the complexity of the restoration. Prices can vary from several hundred to more than a thousand euros. It is important to consult different dentists for estimates to compare prices and treatment options.

Ceramic or composite inlays-onlays: which one to choose?

The choice between ceramic and composite depends on the preferences of the patient and the dentist. Ceramic inlays-onlays offer superior aesthetics, high strength and better compatibility with dental tissues. Composites, however, tend to be more affordable and may be easier to repair if damaged. It is essential to discuss options with the dentist to determine the ideal equipment for your specific situation.

What reimbursement and coverage for an inlay-onlay?

Reimbursement rates and out-of-pocket costs for inlay-onlays vary depending on insurance coverage and health care systems. It is recommended to check with your health insurance and supplementary health insurance to find out the exact reimbursement amounts.

Dental inlay onlay: feedback and opinions?

Feedback and opinions on inlays-onlays are generally positive. Patients appreciate the aesthetic appearance, durability and preservation of natural tooth structure. However, experiences may vary depending on the practitioner, the material used and the individual needs of the patient. It is important to consult an experienced dentist and conduct research to ensure this option is best for your situation.