The dental crown is the fixed coating that covers the entire damaged tooth and protects the natural tooth by returning the tooth to its natural appearance. If the outer surface of the tooth is lost for various reasons or if the patient demands an aesthetic restoration, zirconia or porcelain crowns are made.
If the tooth that is planned to be crowned has a lot of decay and the dental pulp is damaged, root canal treatment is required before the crown is made. There is a need for a structure that will support the crown in the tooth to be crowned.
Zirconia is obtained by adding yttrium oxide to the zirconium element. It has high pressure resistance and is hard. Since its thermal conductivity is low, it does not cause hot-cold sensitivity in the patient after treatment. It can be used in monolithic or translucent forms. Since only zirconia is used in monolithic form, a transparent appearance is not expected as in natural teeth. It is generally used on teeth exposed to chewing at the back of the mouth. If the patient has a teeth grinding problem, the tooth with a monolithic crown may cause abrasions on the corresponding natural tooth, since it is hard in material. In the translucent form, the bottom of the crown is covered with zirconia and the top is covered with fine porcelain. Since translucent zirconia has lower compressive strength than monolithic zirconia, it is preferred in anterior teeth for aesthetic convenience.
Porcelain crown consists of ceramic material with metal support structure. Structurally, it has an opaque color and matte texture and is far from natural tooth appearance because it is thicker. Due to metal support, it creates a gray appearance on the gingiva due to reflection, especially in patients with non-thick gingival structure. Not suitable for people with metal allergies. It causes taste difference due to metal. Since the metal thermal conduction is high, the possibility of damaging the pulp is higher as the hot-cold sensitivity increases after the treatment. Its useful life is less than zirconium coating. In case of possible fracture, porcelain crown repair is possible, while zirconium crown cannot be repaired. Since it is common for porcelain crowns to have a gap between the teeth and gums, foods entering through the gap can cause gum infections and bad breath.
In patients whose jaw development is completed, local anesthesia is applied and thinning is done around the teeth. Then, CAD/CAM measurements are taken in the digital environment with intraoral scanning and the stage of producing the appropriate crowns is started. Temporary crowns are placed while the crowns are being prepared.
During the treatment, since the zirconium crown is thinner than the porcelain crown, less shaving is made around the natural tooth to be bonded. There is no difference in the bonding processes made to the natural tooth or the crown support.
If the patient has problems such as clenching, grinding, and gum diseases, the crowns can be damaged quickly. Zirconia crowns have a useful life of 15-20 years, while porcelain crowns are in the range of 10-12 years. When using zirconia or porcelain crowns after treatment, attention should be paid to the foods consumed. Maintenance and controls should be done periodically.
