What is an Inlay / Onlay Filling?
An inlay/onlay filling, a restorative procedure that prioritizes both aesthetics and durability in dental treatment, is a specialized type of filling that aims to restore function to decayed or damaged teeth while preserving their structure. Unlike traditional fillings, these fillings are custom-made in a laboratory environment and designed to perfectly fit the tooth. Inlay/onlay fillings are particularly preferred for large decay cases and when the tooth’s natural structure is preserved as much as possible.
This method offers a long-lasting solution, both aesthetically and functionally. Inlay/onlay fillings allow only the damaged portion of the tooth to be treated, thus preserving healthy tissue. These fillings, with their high structural durability, can last for years without any problems when applied correctly. Inlay/onlay fillings, which maximize the integrity of the tooth and chewing function, are among the most successful restorative methods in modern dentistry.
What is the Difference Between Inlays and Onlays?
While these two types of fillings are applied in similar ways, they differ in the area they cover and the tooth surface they are treated with. An inlay is placed in the grooves on the chewing surface of the tooth and does not interfere with the cusps (protruding areas). Therefore, it is preferred for smaller damage or decay. Within the inlay/onlay classification, an inlay is less extensive.
An onlay filling, on the other hand, is designed to cover both the chewing surface and the cusps of the tooth. This means it restores a larger area. Onlay fillings are preferred in cases where a larger filling is needed but the tooth can be protected without a crown. This distinction between an inlay and an onlay filling is determined by the dentist’s clinical evaluation.
Both methods are laboratory-supported and offer superior aesthetic and long-lasting properties compared to traditional fillings. The natural structure of the tooth is preserved while also reducing the risk of fractures and cracks.
In Which Situations Are Inlay/Onlay Fillings Preferred?
This restorative method is particularly preferred for tooth damage that would not be sufficient for traditional filling applications, but does not require a full crown. Inlay/onlay filling applications are preferred in the following situations:
- If there is a large-scale decay on the chewing surface of the tooth,
- If old fillings fall out or lose their function,
- When it is necessary to preserve the structural integrity of broken or cracked teeth,
- In posterior tooth treatments where aesthetic appearance is important,
- In teeth with excessive material loss but not requiring root canal treatment.
In such cases, inlay/onlay fillings are used to restore the tooth’s original form and ensure long-term use. They offer advantages in both durability and aesthetics, and they support the natural structure by minimizing abrasion to the tooth’s tissue.
How is an Inlay / Onlay Filling Done?
This treatment is usually performed in two stages. In the first session, the tooth is prepared; any decayed or damaged areas are cleaned and the necessary shaping is performed. Impressions of the area are then taken and sent to the laboratory. The inlay/onlay filling is custom-made according to these measurements.
In the second appointment, the filling received from the laboratory is rehearsed on the tooth. After checking the color, fit, and marginal integrity, it is secured with special adhesives. Precision is crucial in the application of inlays/onlays, as both aesthetic and functional success depend on the perfect fit of the filling to the tooth.
Treatment typically lasts between one week and 10 days. During this time, the tooth is protected using a temporary filling. After the inlay/onlay is placed, the tooth is polished to achieve a natural appearance.
What materials are inlay/onlay fillings made of?
The materials used are selected based on both aesthetic expectations and durability. The most commonly preferred materials for inlay/onlay filling applications are:
Porcelain (ceramic): Offers the closest appearance to natural tooth color. It is preferred by patients with high aesthetic concerns.
Composite resin: It provides an aesthetic advantage because it is tooth-colored; however, its long-term durability is not as high as porcelain.
Gold alloys: Highly durable, but aesthetically pleasing. They are especially preferred in areas with high chewing force.
The dentist determines the material selection based on the patient’s oral structure, tooth color, chewing habits, and expectations. Choosing the right material for inlay/onlay fillings directly impacts both the success and longevity of the treatment.
What are the advantages of inlay/onlay fillings?
This special type of filling offers many advantages over traditional methods, both in terms of aesthetics and durability. Inlay/onlay fillings maximize the preservation of the tooth’s natural structure, ensuring a healthier long-term restoration.
The main advantages of this filler are:
- It fits perfectly to the teeth and balances the chewing force.
- Since it is prepared in a laboratory environment, it is produced with high precision.
- It aesthetically mimics the appearance of natural teeth.
- The healthy tissue of the tooth is preserved; unnecessary abrasion is not done.
- It is longer lasting than traditional fillings.
- Color change and abrasion resistance is higher.
For all these reasons, inlay/onlay filling is a modern solution that meets both functional and visual expectations.
Differences Between Inlay/Onlay Fillings and Classic Fillings
While both methods are used to repair decayed or broken teeth, there are significant differences in their application method and durability. While inlay/onlay fillings are prepared with laboratory support, traditional fillings are applied directly by the dentist in a single visit.
While inlays/onlays provide a more precise and permanent fit to the tooth, traditional fillings can carry the risk of leakage and wear over time, especially in cases of extensive decay. Furthermore, porcelain inlays/onlays offer a more natural appearance than traditional amalgam or composite fillings.
When these differences are evaluated, inlay/onlay filling is a more permanent, durable and aesthetically superior option.
How Long Does It Take to Perform an Inlay/Onlay Filling?
Treatment is usually performed in two sessions. In the first session, the decay is removed, the tooth is prepared, an impression is taken, and a temporary filling is placed. This procedure takes approximately 30–45 minutes. The inlay/onlay is custom-made in the laboratory and then permanently bonded in the second session.
Total treatment time varies between one week and 10 days, depending on laboratory workload. The second appointment is typically completed within 30 minutes. At the end of this process, the inlay/onlay filling is a perfect fit for the tooth, both aesthetically and functionally.
Are Inlay/Onlay Fillings Long Lasting?
A properly applied and well-maintained inlay/onlay can last an average of 10 to 15 years. The quality of the material used, oral hygiene, chewing habits, and regular checkups directly impact this process.
When using highly durable materials like porcelain or gold, inlays/onlays become much more durable. Therefore, they are a reliable restoration option for both aesthetic and functional needs.
What Should You Pay Attention to After Inlay/Onlay Filling?
Very hot or very cold foods and drinks should be avoided for the first 24 hours. It is recommended not to eat for 1–2 hours after the inlay/onlay filling application. Additionally, careful chewing pressure should be used to ensure the filling fully adapts.
Maintaining good oral hygiene is crucial for maintaining the health of the dental tissue supporting the filling. Avoiding overbiting on hard foods and attending regular dental checkups will prolong the life of your inlay/onlay.
Inlay / Onlay Filling Prices 2026
The cost of this type of treatment varies depending on the type of material used, the location of the tooth, the size of the filling, and the laboratory process. Materials such as porcelain or gold are more expensive than composite fillings.
What determines the difference between inlay and onlay fillings?
The difference between the two types of fillings is determined by the area covered by the filling and the structural condition of the tooth. An inlay filling covers only the cavities on the chewing surface of the tooth, while an onlay filling covers the cusps (ridges) of the tooth along with the chewing surface.
The dentist evaluates the selection of an inlay/onlay filling based on the extent of tooth material loss. Inlays are preferred for smaller damage, while onlays are more suitable for larger surface areas. Both treatments are effective solutions for protecting the tooth and restoring its function.
Will these fillings fall out?
When properly applied, an inlay/onlay filling won’t fall out easily because it’s secured to the tooth with special adhesives. However, over time, poor oral hygiene, excessive force on the tooth, or decay can weaken the filling’s hold.
The risk of falling can be minimized by proper filling placement and using high-quality materials. If an inlay/onlay falls out, this usually indicates a problem with the underlying tooth, not the filling itself, and should be evaluated by a dentist.
Do inlay/onlay fillings cause pain?
Temporary tenderness may be experienced after the procedure, but severe pain is generally not experienced. An inlay/onlay filling is a treatment designed to eliminate pain caused by a cavity or crack. When applied correctly, it does not cause pain; rather, it alleviates existing pain.
If you experience pain when biting after a filling, there may be a problem with the fit, such as a high filling. This can be resolved with a simple adjustment. Persistent pain is rare and usually indicates another dental problem.
Which material is more durable: porcelain or composite?
Porcelain materials are harder and more wear-resistant than composites. Therefore, porcelain inlays/onlays are preferred when long-lasting and aesthetically superior results are desired. Composite fillings, while more cost-effective, lag behind porcelain in terms of durability.
Porcelain is more advantageous in areas with high chewing force and in cases where aesthetic concerns are paramount. Material selection is determined by the patient’s needs, habits, and budget.
Will there be sensitivity after inlay/onlay filling?
It’s normal to experience some short-term thermal sensitivity (hot or cold) after treatment. Because inlay/onlay fillings don’t directly interfere with the inside of the tooth, this sensitivity is usually mild and temporary.
The duration of sensitivity can range from a few days to a week. If this condition persists or worsens, the fit of the filling and surrounding dental tissues should be checked. With proper care and regular checkups, this sensitivity will quickly disappear.
How many years do these fillings last?
Depending on the material type, application technique, and patient care habits, the lifespan of inlay/onlay fillings can range from 10 to 15 years. Porcelain or gold alloy fillings are longer-lasting than composite materials.
With regular oral care and routine dental checkups, this period can be extended even further. Inlay/onlay fillings offer a more advantageous option compared to traditional fillings due to their longevity.
Can inlays/onlays be applied after root canal treatment?
Yes, because root canal treatment can weaken the tooth’s structure, an inlay/onlay filling is an ideal solution. This method strengthens the tooth’s structure and provides a natural aesthetic appearance.
Inlays/onlays are particularly effective after root canal treatment in back teeth, especially in cases where a crown isn’t required but additional support is needed. This provides functional support to the root canal-treated tooth and makes it more resistant to chewing pressure.