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 development appliances, an area of bone under compressive force from a tooth moving toward it has a high osteoclast level, resulting in bone resorption. An area of bone receiving tension from periodontal ligaments attached to a tooth moving away from it has a high number of osteoblasts, resulting in bone formation. Thus, the tooth or teeth are slowly moved along the jaw so as to achieve a dentition that works in harmony. In this way, the width of the space between the alveoli and the root is kept about the same. The connection between the gingiva and the tooth is called