Dentures include movable dentures that patients can take and wear freely, and fixed dentures that they cannot take and wear themselves. Dentures become black mainly pigmentation and material oxidation for two reasons. 1, pigmentation: refers to the denture surface pigmentation, food, drugs, cleaning is not in place, long-term smoking, often drink strong tea and coffee and other pigmented beverages, can lead to pigmentation, resulting in dentures become black; 2, material oxidation: most fixed dentures for porcelain teeth, porcelain teeth will reveal the black crown when chipped, if the whole mouth or most of the mouth replacement dentures, plastic dentures may be plastic in nature, plastic dentures may have a black inner crown. If the whole mouth or most of the oral cavity replacement dentures, denture materials may be plastic in nature, plastic dentures may have the phenomenon of oxidation, will make the teeth black. When the dentures become black, they need to be cleaned and disinfected in a timely manner. For movable dentures that can be removed, they should be removed promptly for careful cleaning and then placed in cold water for soaking. Normally, you can also choose professional dental disinfectant to disinfect your teeth in order to remove plaque from the surface of the dentures and the gaps between the teeth. Usually, you should reduce the intake of strong tea, coffee and pigmented food to avoid darkening of teeth, and scaling can be done if necessary.