Tooth whitening enamel layer may also be gradually thinned or even perforated by the various forms of tooth wear. Teeth may be darkened by a buildup of surface stains (extrinsic staining), which hides the natural tooth color; or the tooth itself may discolor (intrinsic staining). Extrinsic stains can become internalised through enamel defects or cracks or as a result of dentine becoming exposed but most extrinsic stains appear to be deposited on or in the dental pellicle. Causes of extrinsic staining include: Changes in the thickness of the dental hard tissues would result in intrinsic discolouration. There are a few causal factors
Human tooth sharpening teeth-filing, including the Bemba, Yao, Makonde, Matambwe, Mboghwa and Chipeta. Human tooth sharpening Human tooth sharpening is the practice of manually sharpening the teeth, usually the front incisors. Filed teeth are customary in various cultures. Many remojadas figurines found in part of Mexico have filed teeth and it is believed to have been common practice in their culture. The Zappo Zap people of the Democratic Republic of Congo are believed to have filed their teeth. Historically it was done for spiritual purposes, with some exceptions, but in modern times it is usually aesthetic in nature as an extreme form of