Q. Hello Dr. Moore: I went to the dentist yesterday and told him I had an occasional sensitive feeling in my lower left molar when I chewed certain food like a piece of muscle in meat. He took a look at the molar and said there was a vertical fracture in the back of the molar that went to the gumline. He said it probably needed a crown. I knew nothing about crowns, so when I researched on the internet it says that usually the perform a root canal on a cracked tooth before putting on a crown. Is it possible to put just a crown on my tooth without a rootcanal? Also, I read that porcelain crowns tend to cause unequal biting pressure on the opposite side tooth causing quicker wear. So I was thinking the best kind of crown would be a high noble metal crown. Is a high noble metal crown gold? One other question, does a crown have to cover the entire tooth down to the gumline or can it just cover like half or 3/4 of the entire tooth?