The rate of change of crowns depends on the material from which they are made. The most commonly used metal, ceramic and metal-ceramic crowns. Of metal crowns in Russia, the most common steel-plated titanium and gold. Crowns are made of different techniques, from which also depends on their lifetime. Gold falling faster than steel, so their owner needs to be especially attentive to their teeth. Preferably after four or five years of wearing crowns to visit a doctor who will examine you and say, is it not time to change them.
Ceramic crowns, they are the same in common – porcelain, have high aesthetics. They mimic the transparency of the tooth, do not absorb dye and can not be erased. Their only disadvantage is low strength. Often ceramic crowns are used on front teeth where you want the most natural look with minimal loads. The owner of the porcelain crowns should worry about replacing them after eight to ten years.
In the metal-ceramic crowns, first made a steel frame to which the subsequently added ceramic. This tooth has a and durability, and a decent aesthetic look, only slightly less in this all-ceramic crowns. The main disadvantage of these crowns is that they wear out the adjacent teeth. Similar crowns can last up to fifteen years.
Even if the life of the crown has not yet passed, signal that it is time to change, will be inflamed gums "repaired" tooth stuck pieces of food, bare roots. In addition, the physician must regularly inspect the tooth wearing a crown. If no change in the dental cavity, and the tooth is healthy, as long as you don't have to worry about replacing the crown.