The dark coloration or black patches that appear on the gums of some people is actually quite normal and is caused by the deposition of melanin in the tissues. It is this same pigmentation that causes some individuals to have darker skin and even freckles. Since the lining inside the mouth is pink, these areas of melanin appear to be dark blue or black instead of brown as they are in the skin. Some individuals have greater amounts of this deposition thereby causing darkening to the gums. Anglo-Saxon people originating from the north of Europe have virtually no pigment in the gums therefore the gums are pale pink.
Pigmentation can range in shades from very light pink all the way to dark black patches.
If you are concerned about the color of your gums be sure to check with your dentist. In the year 25 B.C. through 50 A.D, Celsus, like Hippocrates believed that general physical deterioration was the cause of dental diseases. For toothaches he prescribed, hot water fomentations, narcotics, mustard seed, counter irritants use of the cautery, alum for soft tissue disease and extraction of badly broken down teeth. He recommended filling the cavity with lead prior to extraction as a means of lessening the chance of fracturing the crown. He is credited with providing the technique for reducing fractures and was also credited with the first technique for tooth straightening or positioning.