Tooth discoloration Light hitting a tooth undergoes reflection, absorption and transmission by varying degrees in each tissue layer of the tooth substance. Reflected light detected by the human eye determines the perceived appearance of a tooth. Teeth have a thin enamel layer on the outer surface. The enamel layer is whiter and semitransparent, and contributes blue, pink green tints to the tooth color. The underlying dentin layer is darker than enamel, yellow-brown in color, and less transparent. Dentin forms the bulk of the tooth substance, and contributes most to the overall tooth color. At the core of the tooth is soft connective
Human tooth cause of tooth impaction is lack of space in the mouth for the tooth. Other causes may be tumors, cysts, trauma, and thickened bone or soft tissue. Tooth ankylosis occurs when the tooth has already erupted into the mouth but the cementum or dentin has fused with the alveolar bone. This may cause a person to retain their primary tooth instead of having it replaced by a permanent one. A technique for altering the natural progression of eruption is employed by orthodontists who wish to delay or speed up the eruption of certain teeth for reasons of space maintenance or