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.
Dentin is the layer of the tooth just under the enamel. It is yellow in color. It is also softer that enamel. It is one of the three layers of the tooth. The enamel is the outer layer, the dentin is the middle layer, and the pulp is the inside layer. Decay that has extended to this layer of the tooth can spread rapidly, and needs to be treated quickly by a dentist.