It's also possible that you have the correct application on your PC, but .afp files aren't yet associated with it. In this case, when you try to open a .afp file, you can tell Windows which application is the correct one for that file. From then on, opening a .afp file will open the correct application.
Dentin is found underneath the enamel surface of the tooth and underneath the cementum that forms along a tooth's roots. Made of living cellular material and tissue, dentin is what makes up the majority of a tooth's structure. Dentin is a bone-like substance that contains microscopic tubules. Unlike enamel, exposed dentin is highly susceptible to the bacteria that cause dental cavities and can cause tooth sensitivity. Cementum.
Tissue which makes up the main bulk of the tooth; lies under the enamel of the crown and the cementum of the root; softer than enamel but harder than cementum and bone; has no nerves but carries sensations of pain and temperature to the pulp; a living tissue which is capable of limited repair and continued growth; forms the wall of the pulp chamber ...