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What are dental inlays and onlays?

Suppose one of your teeth has decayed due to any reason and this decay has caused a small hole in your tooth. Normally, when you visit a dentist in Canada, the dentist fills the tooth cavity with the help of special filling materials. But if a large part of the tooth is lost and the cavity is too big, filling materials will not be effective. In this case, dentists use methods called inlays and onlays to fill the created cavity. But what are dental inlays and onlays, what are their differences, what are their advantages and disadvantages, and how do they help maintain the function of your teeth, read in this complete and comprehensive article.

An introduction to dental inlays and onlays

Tooth filling is the most basic, but the most effective way to restore the tooth and restore its functionality. There are many different types of filling materials and they are able to prevent the accumulation of bacteria and microbes in the cavity by closing the created tooth cavity in addition to maintaining the person’s chewing power. In fact, closing the teeth with filling materials also means preventing the occurrence of diseases. Therefore, filling is a very effective treatment method.

With the progress of cosmetic dentistry, now filling materials are produced in the same color as the teeth, which makes no one notice that your teeth are filled and the desire to use them increases. But in addition to the usual methods of filling the tooth cavity with these materials, which most of us are familiar with and have almost certainly experienced at some point in our lives, there are two other methods of filling the tooth called inlays and inlays. There is. We use these methods to fill larger holes than usual. In the following, you will be fully acquainted with each of these two methods and the difference between dental inlay and dental onlay.

What is dental inlay?

Dental inlays actually have the same function as dental fillings. In this method, we repair the part of the tooth that is excessively decayed and the decay is more in the middle part of the tooth. After removing the decayed part and cleaning around it, we inlay the tooth.

The principle of the tooth inlay process is very similar to tooth filling, but instead of filling the interior and hollow space of the teeth, the inlay uniformly fills the space. Usually, the material used in this method is mostly gold because it is strong enough, durable and beautiful. Unlike silver or other types of fillers, gold does not tarnish and can withstand the pressure caused by chewing food.

Recently, porcelain materials are also used to cover the teeth, which can last up to 10 years. And depending on the material used, these layers will last at least ten years.

Who should do dental inlays?

Patients with severely broken or decayed teeth are ideal candidates for inlays. Because excessive tooth decay cannot be repaired through other methods such as tooth filling with composite. Direct restoration with conventional fillings only aggravates the condition and even compromises the structural integrity of the tooth. The use of fillers such as composite or amalgam for such teeth cannot withstand the pressure and will lead to more dental problems in the future. After the operation, the patient must tolerate all the daily actions related to the tooth, such as chewing and the pressure caused by it, without feeling pain or discomfort.

What is a dental Onlays?

Onlays are a larger version of inlays where most of the molars have eroded and decayed. As you know, molars have 4 lateral ridges, and when more than two ridges are damaged, we use dental inlays instead of normal filling materials for restoration. Therefore, the difference between dental inlay and dental Onlay is actually the extent of their coverage and support for damaged teeth. If the damage is small and only two ridges have been created from the back tooth, we use an inlay, and if it is more than two, we use a dental Onlay.

Placement steps of dental inlays and Onlays

Before performing the operation, an initial visit with a dentist is necessary. This is done to assess the extent of the damage and ensure that inlay is the only repair method necessary. During the second visit, the inlay is usually installed. This is while filling teeth with filling materials can be done in one session.

So that a person does not experience pain; Local anesthesia can be used on the tooth and surrounding tissues. Patients can also choose other types of sedatives such as nitrous oxide for anesthesia.

Inlays and Onlays can be installed in the dental clinic in one session, but if the decay is excessive or the patient needs and wants gold or ceramic materials, inlays are done in two stages and in two sessions. (This type is called indirect inlay and after molding from the tooth cavity, the replacement part must be made in the dental laboratory and then sent to the clinic for use)

Direct tooth inlay and Onlay stages

  1. Before placing the inlay fillings, the decayed part of the damaged tooth is removed.
  2. Then the dentist places the composite resin on the tooth to mold the shape of the damaged part or the same cavity. This composite resin mold can be hardened in a special oven and used
  3. When this filling material is hard enough, the dentist attaches this layer to the patient’s tooth with the help of special cement.

Placement steps of indirect inlay and Onlay

  1. To perform an indirect inlay, the dentist cleans the tooth similarly
  2. The dentist sends the mold to the laboratory
  3. Until the inlay is made, the dentist closes the cavity with a temporary filling material.
  4. Then, when the inlay mold arrives from the laboratory, the dentist connects it to the damaged tooth with the help of the same special cement during another session.
  5. After the operation, the patient should maintain oral hygiene by brushing and flossing regularly. Regular visit to the dentist is also necessary.

What are inlay and Onlay made of?

  • porcelain
  • Plastic
  • Precious metals (gold).

The benefits and advantages of inlays and Onlays

  • Compared to dental fillings that are made of composite resin or amalgam, one of the benefits of dental inlays is their coverage and longevity. They strengthen up to 75% of teeth and last 25 to 30 years with proper care.
  • They prolong the life of the tooth and prevent the need for further dental treatment in the future.
  • Both methods protect the crown of the tooth. They allow the dentist to preserve more and more effectively the natural structures of the tooth.
  • One of the most important advantages of dental inlays and onlays is their natural results. They have a completely beautiful and natural appearance.
  • They are made with the help of modern CAD-CAM technologies, which is a combination of advanced computer software, 3D scanner and milling unit. This technology allows for precise installation.
  • The raw materials for these two methods do not contain any allergenic substances. Therefore, they can be safely used for tooth restoration.
  • The disadvantages of inlays and onlays are very few compared to their advantages.


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