Human tooth of tooth loss can be rapid since enamel is very thin in this region of the tooth. A common source of this type of tooth wear is excessive force when using a toothbrush. Erosion is the loss of tooth structure due to chemical dissolution by acids not of bacterial origin. Signs of tooth destruction from erosion is a common characteristic in the mouths of people with bulimia since vomiting results in exposure of the teeth to gastric acids. Another important source of erosive acids are from frequent sucking of lemon juice. Abfraction is the loss of tooth structure from flexural
Crownshaft It is usually green in color but may be a different color from that of the leaves themselves, including white, blue, red, brownish or orange. Each layer of the crownshaft is a distinct leaf base and is usually made of a tough fibrous material with a feel similar to leather and in many parts of the world, it is cured and used to prepare covers, sheets and roofing material. The leaf base of some palms are also used to extract coir. The oldest leaf forms the outermost layer of the crownshaft. Eventually the lowest palm frond dies back, the outer