If you have had the standard crown place you are likely to have a combo of nickel/palladium in the crown whcih on itself can create a whole slew of problems. Having dissimilar metals in your mouth will create battery like affect and speed up the poisoning, as well as interfere energetically with the specific meridians they are located.
So whether or not you have mercury under it your likely to have poison in the crown itself. If you go to a qualified hollistic dentist with experience with EAV/meridian stress assessement he can check those particular teeth locations and see if they are stressing your system (affecting your health). There are some people with root canals and Amalgams in their mouth without any symptoms or problems and when testing on EAV on the teeth in question, it shows that those bad teeth might not be posing an immediate threat to their health (at that point in time) and can continue with their lives (although they should check periodically to monitor changes).