Mar 18, 2016. There are 11 major organ systems in our body. This includes the circulatory, respiratory, digestive, excretory, nervous, and endocrine systems. As well as the immune, skeletal, reproductive, muscle and integumentary systems.
Dental crowns can be made up of all different sorts of materials -- porcelain or a combination of porcelain with metal. The type that's chosen not only depends on where the tooth is situated, but what the condition of the tooth is (how discolored it is and how decayed it is), as well as the condition of the gums.
Crowns. A crown is a tooth-shaped cap that's placed over a weak or damaged tooth to improve its shape, size, strength, or appearance. Most crowns last five to 15 years and can be made of metal, porcelain fused to metal, resin, or ceramic. Before a crown is seated, the existing tooth is filed down; then the crown is cemented over it, fully encasing the tooth. Onlays and three-quarter crowns cover the underlying tooth to a lesser extent.