Do Cosmetic Teeth Smell and Taste Like Metal ?

The first thing I would suspect is leakage around the crowns.  This can often be seen quite easily with x-rays, but sometimes a dentist can put his explorer (instrument that detects decay and openings around dental restorations) into the opening.  If that's the case, the restorations will have to be redone.

The metal underneath the crowns may be the source of the metallic taste.  The irritation may actually be a low grade allergy to the metal (as you probably know, some people are even allergic to jewelery). 

If your crowns need to be replaced I suggest asking for all-ceramic non-metal based crowns.  They are highly bio-compatible and also much more natural looking than  porcelain-fused-to-metal crowns.  My favorite porcelain for front crowns is EMax porcelain.

Bottom line, see your dentist and have him carefully evaluate your five year old dentistry.

sounds like you need to see a dental professional. Often gum infection does not involve pain. There are tests that can be done to check if you have gum or bone infection. There also are crowns that do not have metal in them that you could consider. good luck!

yes, this can happen, if there is a leackeage in those crowns, 

could be the crowns, or could be a gum pocket, also, gums, can present sometimes recession, and this can cause food to be trapped, also,with an x-ray we can surely know what is happening there, and i think your solution its not too dificult,