Why are my gums grey around my 2 back teeth? Both had root canals & porcelain crowns (Photo)

You probably had an amalgam filling in the previously extracted teeth and due to the penetration of this amalgam filling into the tissue during extraction, the image we call amalgam tattooing has occurred. This is not a problem that requires treatment. Another reason for the dark appearance is the reflection of the metal under your porcelain veneer from the gums, and crowns made of Zirconium material can be applied to reduce this.