The last cap my dentist put on over a year ago, is gold.  I started noticing sensitivity to cold & hot to it.  It is completely black around the crown & down in my gum.  I went back to my dentist & he poked around the top of the cap & I felt no pain.  He said it was a black tattoo & laughed.  Then my sister who was a dental assistant for years said she thought the tooth was dead.  It has been over a month since I went to the dentist & now on the left side of my mouth another cap looks like a blister along the gum line.  What do you think?  Thank You
Hi. Thanks for the query. As per your complaint and explanation of symptoms if there is blister over the gum of the tooth that has a cap can be most probably due to secondary decay in tooth caused due to seepage of fluids and debris between the cap and tooth. It can also be due to deep Infection in the gums leading to accumulation of bacteria deep into the gum pocket leading to pus formation and formation of a Gum Abscess. Black discoloration around tooth along with sensitivity to hot and cold is also indication of infection in tooth and not simply tattoo. So my suggestion is to consult an Endodontist and get evaluated and a thorough clinical evaluation and investigation like x-ray of both the capped teeth has to be done followed by appropriate treatment. In case of tooth decay removal of cap followed by Root Canal Treatment can help. In case of gum Infection deep scaling and Curettage can help. Hope your query is resolved. Regards.