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.
The major portion of a tooth consists of dentin, which is harder than bone; enamel; and cementum, which is similar to bone. The pulp cavity contains the dental pulp. Each tooth has five surfaces: occlusal, mesial, distal, lingual, and facial or buccal. See: illustration; dentition.