A combination crown is a metal crown in which the veneer applied to the vestibular surface is made of plastic or porcelain. The safety and strength of the entire structure provides a cosmetic effect when using this type of crowns. The metal vestibular surface or its excised area is the basis for the lining of the combined crown.
This type of crown is suitable for those people who wish to give an aesthetic appearance to their front teeth, including premolars. They can be used both independently and as a support for a bridge prosthesis.
In modern medicine, the most common design is the combined crown, proposed by M.Ya. Belkin in 1947.
In what cases is the use of a combined crown recommended?
- in case of damage and destruction of the natural crown as a result of tooth decay by caries, the presence of pathological wear and wedge-shaped defects, which makes it impossible to use fillings, inlays and porcelain crowns ;
- the presence of various anomalies in the shape and color of the tooth;
- the need to restore the anatomical shape of the tooth;
- the presence of a deep overlap of the front teeth or a deep bite, which makes it impossible to separate the antagonizing teeth.
Contraindications for the use of combined crowns
Despite the wide popularity of combined crowns among patients, there are a number of contraindications to their use, which significantly limits the number of people who want to install them:
- the presence of untreated foci of inflammation of the chronic, marginal or apex of the periodontium;
- dental deposits;
- the presence of intact teeth;
- pathological tooth mobility of the 3rd degree;
- the presence of milk teeth.
Advantages of combined crowns
What are the advantages of using combined crowns?
- For the manufacture of this type of crowns, only durable materials are used, which increases the service life.
- In this type of crowns, all the positive qualities that can be distinguished in metal and plastic crowns are combined;
- They make teeth aesthetically attractive with the correct selection of the color range of plastic.
Disadvantages of combined crowns
Are there any disadvantages to using combined crowns?
- when using plastic for lining the metal frame of an artificial crown, a decrease in aesthetic appearance can be observed, which occurs as a result of a change in the color of the plastic, especially at the junctions with the frame along the edge of the window;
- small gaps form at the junctions of plastic and metal, through which oral fluid and food debris enter. All this is an ideal environment for the development of decay and fermentation processes, which further increase the separation of materials, cause the destruction of the hard tissues of the natural tooth pulp, and also contribute to the discoloration of the plastic.
- significant preparation of the labial surface of the crown.
