<s>[INST] yes I wish I could convey my alarm. I just looked in my husbands mouth and his teeth have turned all black and rotten. I beleive this has happened in the last year....since he has had a chronic cough. The Dr. has never noticed this during his annual physical. He is 71. [/INST] Thanks for your query, I have gone through your query. The black discoloration of the teeth could be because of the stains or decay. Consult an oral physician and get yourself examined to rule out these things. If it is stains then get your teeth cleaned once. If it is decayed teeth then get the teeth restored. When it is in the initial stage you get it restored otherwise it will get infected and results in pain swelling and other complications. I hope my answer will help you, take care. </s>