Stained tooth is a cosmetic problem. Consult your dentist if you have stained teeth and it bothers you. In a child any change in color of a tooth should be evaluated.
Consult your dentist if you have pain in your molar teeth as an impacted tooth can cause various problems such as damage to neighboring teeth, distortion of the bite.
Dementia progresses slowly over time and after diagnosis, the doctor will recommend regular follow-ups to assess mental function and other problems.