Short answer: A zirconia crown is a type of crown made from zirconium oxide ceramic instead of a metal framework, which fully covers the tooth. Because it lets some light through, it looks close to a natural tooth, does not create a gray line at the margin and is compatible with the gums. For the procedure, tooth structure is removed, an impression is taken and the treatment is completed in a few visits. Its lifespan depends on oral care and regular check-ups.
For teeth that are broken, heavily filled, root canal treated or noticeably discolored, a crown is one of the most frequently recommended treatments. In recent years, zirconia has become one of the most talked-about materials in this area. A zirconia crown is a dental crown made from a durable ceramic called zirconium oxide instead of a metal framework. In this article we explain what zirconia is, how it differs from metal-supported crowns, the treatment steps, its advantages and disadvantages and what to pay attention to so that it lasts a long time.
What is a zirconia crown?
A zirconia crown is a type of fixed prosthesis in which a crown that fits over and fully covers a tooth, or a bridge that joins several teeth, is made from zirconium oxide ceramic. Among ceramics, zirconia is known for its high fracture resistance. Thanks to its white color and its ability to let some light through, it allows results that look close to natural teeth.
Zirconia crowns are generally made in two ways:
- Monolithic zirconia: The entire crown is made from a single piece of zirconia. It is highly durable and is preferred especially for back teeth, where chewing forces are greater.
- Layered zirconia: Aesthetic porcelain layers are added on top of a zirconia framework. It can be used on front teeth to achieve more natural translucency and color transitions.
Zirconia crowns are produced with computer-aided design and manufacturing (CAD/CAM) systems. A digital or conventional impression of the tooth is taken, the crown is designed on a computer and milled from a zirconia block. It is then fired to harden it, colored and polished.
Zirconia can be used not only for single crowns but also for bridges and implant-supported prostheses. Which teeth it will be used on and which design will be used is decided by assessing the bite relationship and aesthetic expectations.
How it differs from metal-supported crowns
The basic difference between a zirconia crown and a porcelain-fused-to-metal crown is whether there is metal in the framework of the crown; this difference affects both appearance and tissue compatibility. Metal-supported crowns have a metal framework inside and tooth-colored porcelain outside. In a zirconia crown, the framework is also white ceramic.
- Translucency: Metal does not let light through. For this reason, metal-supported crowns can look more opaque and dull in some lighting conditions. Zirconia lets some light through and can offer an appearance closer to a natural tooth.
- Gum margin: When the gum recedes over time, a gray line may become visible at the margin of metal-supported crowns. Because the framework of zirconia is white, this problem does not occur.
- Tissue compatibility: Zirconia is a material that is well tolerated by gum tissue. It can be chosen as an alternative for people with metal allergies.
- Clinical track record: Metal-supported crowns have been used for decades and have abundant long-term data. Zirconia has also been in use for many years, and clinical experience continues to grow.
Both options have their place. The choice is made together with the dentist according to the position of the tooth, bite forces, aesthetic expectations and the person's particular situation. In some cases, other all-ceramic materials such as glass ceramics may be considered besides zirconia.
How are zirconia crowns made? The treatment steps
A zirconia crown is usually completed over a few visits, going through examination, tooth preparation, impressions, try-in and cementation. The process roughly proceeds as follows:
- Examination and planning: The condition of the teeth and gums is examined and the necessary X-rays are taken. Any decay is removed; if there is a problem with the nerve of the tooth, root canal treatment may be done before the crown. Any gum inflammation is treated first.
- Tooth preparation: Under local anesthesia, the tooth is shaped by removing tooth structure from its outer surface equal to the thickness of the crown. Thanks to the strength of zirconia, less structure may be removed in some cases; however, this always means an irreversible preparation.
- Impression: An impression of the prepared teeth is taken digitally with an intraoral scanner or with conventional impression materials. The bite is recorded and the shade is selected.
- Temporary crown: Temporary crowns are placed to protect the teeth, reduce sensitivity and maintain appearance until the final crown is ready.
- Try-in: The crowns made in the laboratory are tried in the mouth; fit, bite, color and shape are assessed. Adjustments are made if needed.
- Cementation: After the final checks, the crowns are permanently fixed in place with a suitable cement. Minor discrepancies in the bite are adjusted and care instructions are given.
If the teeth are misaligned, a short course of orthodontic alignment before crowns can allow less tooth structure to be removed. This option can be discussed with the dentist, especially by adults considering crowns on their front teeth for aesthetic reasons.
Advantages and disadvantages
The main advantages of zirconia crowns are their aesthetic appearance, durability and tissue compatibility; the main disadvantages are that tooth preparation is irreversible and that repair can be difficult in some cases.
Advantages
- Can offer color and translucency close to a natural tooth.
- Thanks to high fracture resistance, can also be used on back teeth.
- Compatible with gum tissue; a suitable option for people with metal allergies.
- No gray line forms at the margin.
- When the surface is well polished, it tends to attract little plaque and resists discoloration.
Disadvantages
- Enamel and dentin are removed to prepare the tooth; this cannot be undone.
- In layered zirconia, small chips may occur in the outer porcelain layer over time.
- Zirconia whose surface has not been adequately polished can cause wear on opposing teeth, so surface finishing is important.
- Because it is a very hard material, removing it when necessary and repairing it in the mouth is difficult.
- The tooth under the crown can still decay; the crown margins in particular need to be cleaned well.
Lifespan and care
With good oral care and regular check-ups, zirconia crowns can be used for many years; the most important factors determining the lifespan of a crown are the health of the underlying tooth and gums and the person's habits. The crown itself does not decay; however, plaque that builds up at the junction between the crown and the tooth can cause decay in the underlying tooth and gum inflammation.
To protect your zirconia crown, you can follow these recommendations:
- Brush twice a day with fluoride toothpaste. Pay attention to the margin where the crown meets the gum.
- Clean between your teeth every day. If you have a bridge, clean underneath it with special floss or interdental brushes.
- Wear a night guard if you clench or grind your teeth. This habit can increase the risk of fracture and wear in crowns.
- Avoid biting hard objects. Opening bottle caps, chewing ice and biting your nails can damage crowns.
- Attend regular check-ups. At check-ups, usually every six months, the crown margins, gum health and bite are assessed.
If you have complaints after a crown such as sensitivity, a feeling that the bite is high or bleeding gums, it is recommended that you tell your dentist without waiting for the next check-up. Because fees vary with the number and condition of the teeth, they are communicated in writing after the examination and planning. For other common questions about crowns, you can see our frequently asked questions page.
Considering a crown? Start with an examination
If you are considering zirconia crowns for your teeth, it is important to first discuss whether your teeth really need crowns and whether options that remove less tooth structure might be suitable. At our polyclinic on Kudüs Cd. in Oran, the condition of your teeth, your aesthetic expectations and alternative treatments are assessed together.
Frequently asked questions
How long do zirconia crowns last?
With good oral care and regular check-ups, zirconia crowns can be used for many years. The lifespan of a crown depends on the health of the underlying tooth, the condition of the gums, habits such as clenching and how regularly check-ups are attended. Rather than giving an exact period, it is more accurate to assess these factors individually.
Are teeth filed down for zirconia crowns?
Yes, a certain amount of tooth structure is removed from the outer surface of the tooth so that the crown can fit over it. This is done under local anesthesia and is irreversible. The amount of structure to be removed is determined by the dentist according to the condition of the tooth and the type of crown to be used.
Do zirconia crowns change color?
Thanks to its well-polished surface, the zirconia crown itself resists discoloration. However, the surrounding natural teeth may stain or be whitened over time, which can create a color difference. If you are considering whitening, it is recommended to do it before the crowns.
Is there sensitivity after zirconia crowns?
Especially in vital teeth, mild sensitivity to cold and heat may be felt in the first days after the crown. In most cases this sensitivity eases quickly. If the sensitivity lasts a long time or increases, it is recommended that you see your dentist.
