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.
1 Gold alloys â This crown is a mix of gold, copper and other metals. In addition to providing a strong bond to the tooth, it doesn't fracture, nor does it wear away the tooth itself.  Base metal alloys â This crown is made up of non-noble metals that are highly resistant to corrosion, and make for a very strong crown.