I have a question for a well educated dentist or someone who knows dentistry?

[d*sexy]

i live in ny. i recently had dental work done and i am devastated...I had cavities...i have never had a cavity in my life and I am 23. I specifically told my dentist I did not want amalgam filligs I wanted the Composite ones. He put composite in the right side of my teeth and the amalgam ones on my left side. He put 7 1/2 silver ones. I find that ridiculous because 2 of them are on my upper and lower wisdom teeth and I just got my wisdom teeth in. I dont know what happened to my teeh. Before I had my son I had no cavities and after he was born I had many or so my dentist says. The entire right side has all composite. Than he put 3 amalgam in my left upper teeth and I asked him not to put them in the lower ones. He said he doesnt know how deep they are and he wont know until he drills than he can determine what he will use. Isnt that what x-rays are for? He said if they were too big he would use the amalgam otherwise he would use the composite. He said the amalgam lasts longer. I said I dont want the amalgam. I have 3 in my upper and 4 1/2 in my lower...thats a lot every time I open my mouth all you see is a line of 4 1/2 silver in a row...its horrible...how much would it cost to take all the amalgam ones out and replace them with composite?