A dark tooth doesn´t have to be diseased. The tooth colour mainly is depending on predisposition, the daily use of teeth and the pigmentation of some nutriment like coffee, tea and remployeed wine. Those kind of nutrition can lead to a darkening of teeth. Containments of cigarrette smoke cover the tooth surface and will also lead to darkening.
In case you are not satisfied with your tooth colour, I can offer a solution.
In the beginning of the process, your teeth will be cleaned of deposits through a professional cleaning. Afterwards, through an In-Office-Bleaching done by the dentist or through Homebleaching which can be done at home, the original tooth colour can be bleached by 2 to 3 colour levels.
Prerequisite for Bleaching are healthy, vital teeth without caries.