Problems w/ old amalgam fillings getting loose and causing bigger cavities?

I got a root canal on #4 because old amalgam was loose and was getting stuff under, until the cavity became large to need root canal. Was thinking of just pulling the tooth because would have been cheaper and my teeth are too crowded and need braces (as an adult).





They convinced me not to, so I got the expensive root canal, but only put a temporary crown, at my dentist's suggestion that the perm. crown would be a different shape after the orthodontia.





I moved away and within a year the temporary crown busted and push up into my gum. It never felt good anyway, the feel of the fake material and wished I'd saved the money and had the extraction as my original plan.





Went to a new dentist to fix emergency, she made a new temp crown, and told me all other amalgams were loose and if I didn't want all root canals, I'd change them all now. So I did.





Why didn't the first dentist know this? Now it hurts anyway and prob will need extract. Gum never healed.

Problems w/ old amalgam fillings getting loose and causing bigger cavities?
Amalgam is just like any other metal and shrinks and expands with the heat in your mouth. Composite (tooth colored filling material) does not need as much prep space as a amalgam would. In the long run though, to replace you would need to go with composite because of the re-prepping but amalgams if properly prepped should last ALOT longer.