Human tooth development the dentogingival junction. This junction has three epithelial types: gingival, sulcular, and junctional epithelium. These three types form from a mass of epithelial cells known as the epithelial cuff between the tooth and the mouth. Much about gingival formation is not fully understood, but it is known that hemidesmosomes form between the gingival epithelium and the tooth and are responsible for the "primary epithelial attachment". Hemidesmosomes provide anchorage between cells through small filament-like structures provided by the remnants of ameloblasts. Once this occurs, junctional epithelium forms from reduced enamel epithelium, one of the products of the enamel organ, and divides
Human tooth with an abundance of chlorophyll, restorative materials, and medications. Stains from bacteria may cause colors varying from green to black to orange. Green stains also result from foods with chlorophyll or excessive exposure to copper or nickel. Amalgam, a common dental restorative material, may turn adjacent areas of teeth black or gray. Long term use of chlorhexidine, a mouthwash, may encourage extrinsic stain formation near the gingiva on teeth. This is usually easy for a hygienist to remove. Systemic disorders also can cause tooth discoloration. Congenital erythropoietic porphyria causes porphyrins to be deposited in teeth, causing a red-brown coloration. Blue