To turn on the AutoRecover feature: 1  In Word 2010, from the menu, select 2  . In the window that opens, click the tab, icon, or list item. 3  If it is unchecked, check , and type a value next to minutes. 4  Click to make the change.
What is tooth enamel? Tooth enamel is a hard substance found in the shell of each of your teeth and is the part of the tooth thatâs visible when you look in your mouth. Enamel is considered the hardest substance in the human body. Itâs even harder than your bones; however, it can dissolve or decay when exposed to acid and a build-up of bacteria.
Enamel is the hardest substance in the human body and contains the highest percentage of minerals, 96%, with water and organic material composing the rest. The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. Enamel is formed on the tooth while the tooth is developing within the gum, before it erupts into the mouth. Once fully formed, it does not contain blood vessels or nerves.