Tooth enamel overall process of tooth development. Under a microscope, different cellular aggregations are identifiable within the tissues of a developing tooth, including structures known as the enamel organ, dental lamina, and dental papilla. The generally recognized stages of tooth development are the bud stage, cap stage, bell stage, and crown, or calcification, stage. Enamel formation is first seen in the crown stage. Amelogenesis, or enamel formation, occurs after the first establishment of dentin, via cells known as ameloblasts. Human enamel forms at a rate of around 4 μm per day, beginning at the future location of cusps, around the third or
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