I am scheduled for an mri in dec but i have 2 mercury fillings plus one metal nail in one of my root canalled teeth. is it safe for me to get an mri?

You should: be fine, but inform the MRI technologist of any metal in your body prior to the scan.

Yes, except...: The mercury fillings are not important for MRI studies. The metal nail may be a problem if it is an old treatment or performed in certain countries, most notably the eastern european countries. In these circumstances, it is possible that the tooth with the nail could heat up or become loose with MRI. At your age, that is unlikely, however. Tell details to the MRI tech before you start study.