Healing of Extraction Sockets
The removal of a tooth inltlates the same sequence of inflammation, epithelialization, fibroplasia,’ and remodeling seen in prototypic skin or mucosal wounds. As previously mentioned, sockets heal by secondary intention, and many months must pass before a socket heals to the
degree to which it becomes difficult to distinguish from the surrounding bone when viewed radiographically.
When a tooth is removed, the remaining empty socket consists of cortical bone (the radiographic lamina dura) covered by torn periodontal ligaments, with a rim of oral .epithelium (gingiva) left at the coronal portion. The socket
fills with blood, which coagulates and seals the socket and the oral environment.
The inflammatory stage occurs during the first week of healing; White blood cells enter the socket to remove contaminating bacteria from the area and begin to break down any debris, such as bone fragments, that are left in
the socket. Fibroplasia also begins during the first week, with the ingrowth of fibroblasts and capillaries. The epithelium migrates down the socket wall until it either reaches a level at which it contacts epithellum from the
other side of the socket or it encounters the bed of granulation tissue (i.e., t.issue filled with numerous immature capillaries and fibroblasts) under the blood clot over which it can migrate. Finally, during the, first week of
healing, osteoclasts accumulate along the (festal bone. The second week is marked by the large amount of granulation tissue that fills the socket. Osteoid deposition has begun along the .alveolar bone lining the socket. In
smaller sockets the epithelium may have beeorne fully intact by this point.
The processes begun during the second week continue during the third and fourth weeks of healing, withepithelialization of most sockets complete at this time. The cortical bone continues to be resorbed from the crest
and walls of the socket, arid new trabecular bone is laid down across the socket. It is not until 4 to 6 months after extraction that the cortical bone lining a socket is fully resorbed; this is recognized radiographically by a loss of a distinct lamina dura. As bone fills the socket, the epithelium
moves toward the crest and eventually becomes level with adjacent crestal gingiva. The only visible remnant of the socket after 1 year is the rim of fibrous (scar) tissue that remains on the edentulous alveolar ridge.