Human tooth development the low levels of fluoride incorporation and very mild fluorosis makes the tooth more resistant to demineralization and subsequent decay. Deficiencies of nutrients can have a wide range of effects on tooth development. In situations where calcium, phosphorus, and vitamin D are deficient, the hard structures of a tooth may be less mineralized. A lack of vitamin A can cause a reduction in the amount of enamel formation. Fluoride ingestion has been noted to delay eruption of teeth for as much as a year or more from the accepted eruption dates since the initial 1940s fluoridation trials. Researchers theorize that
Human tooth discoloration may occur with alkaptonuria and rarely with Parkinson's disease. Erythroblastosis fetalis and biliary atresia are diseases which may cause teeth to appear green from the deposition of biliverdin. Also, trauma may change a tooth to a pink, yellow, or dark gray color. Pink and red discolorations are also associated in patients with lepromatous leprosy. Some medications, such as tetracycline antibiotics, may become incorporated into the structure of a tooth, causing intrinsic staining of the teeth. Tooth eruption may be altered by some environmental factors. When eruption is prematurely stopped, the tooth is said to be impacted. The most common