Extraction Socket Healing

01:27 bone, buccal walls, Extraction, healing, necrosis, oral; surgery, osteoblast, osteoclast, wound 12 Comments

Tissue taken from a socket 3 days after tooth extraction was comprised of a fibrin clot
partially infiltrated with inflammatory cells, which were loosely organized and very
fragile. In another sample, tissue taken from a 1-week-old extraction socket
was found to be composed of degenerating fibrin and early granulation tissue


fibrin clot----Granulation tissue----organize into----collagen plug[1 month]----plug increase in density---replaced from the apex and the periphery---by bone deposition



After the development of a fibrin clot, the tissue becomes granulation tissue, which
contains blood vessels, fibroblasts, and chronic inflammatory cells. The granulation
tissue eventually matures into a collagen plug. For example, the authors found that, after
1 month, tissue removed from the center of the extraction site was composed of fibrous
connective tissue and fibroblasts with some remaining inflammatory cells.The
buccal wall and alveolar crest was resorbing with associated gingival collapse and loss of
interdental papilla. The socket enlarged to the buccal, and bone on the buccal alveolar
surface, and alveolar crest resorbed in the area of the extraction site. In this
patient, tooth extraction precipitated a generalized resorptive response in the alveolar
bone.

In tissue samples of the periphery of the soft tissue removed from extraction sockets, new 

bone formation occurred on the old necrotic bone of the original socket wall. 

However, in the same socket, necrotic bone was set free from the underlying vital bone 

and was sloughed into the socket to be expelled as bone sequestra . The  bone of the original socket wall dies and is undermined by osteoclastic resorption. This necrotic bone can form a nidus for new bone growth, or the necrotic bone can be expelled from the socket as bone sequestra. A portion of the old socket wall will form new bone on its surfaces and will become incorporated into bone forming in the extraction socket. However, a significant portion of the old socket wall will be undermined, become 

necrotic, and be sloughed into the oral cavity through the extraction socket orifice.

If the first stage of extraction-socket healing is resorption and disposal of necrotic bone,
then this would explain why tooth extraction in patients on bisphosphonates occasionally
leads to osteonecrosis. The bisphosphonates prevent osteoclastic undermining and disposal of necrotic bone lining the socket wall. The inability of the alveolus to dispose of the necrotic bone lining the socket wall could then lead to progressive osteonecrosis

Even with modern antibiotics, osteomyelitis and osteonecrosis are major medical
challenges. To prevent osteomyelitis and osteonecrosis, bone mounts an inflammatory
response to protect the host.After extraction, a significant amount of bone is sacrificed
by the body, but the host survives.However, with proper treatment, our findings
indicate the resorptive, clotting, granulation, and collagen phases of healing can be
skipped, and the extraction socket can proceed directly from extraction to regeneration.


To skip the negative phases of extraction-socket healing, a biocompatible material must
be placed in the socket after extraction. However, to avoid the resorptive phase of
healing, the graft material should not require resorption before bone formation. The graft
material should be biocompatible, inhibit bone resorption, and stimulate osteogenesis.
Also, to limit bone resorption on the buccal, lingual, and crestal bone surfaces, gingival
flaps that expose this bone should not be raised during placement of the graft material.

The drug component in Socket Graft stimulates osteoblasts and inhibits osteoclasts and
phagocytes. As the calcium phosphate based component of the bone graft is replaced by
bone, the drug component enters the osteoblasts, stimulating osteogenesis. The drug
component is retained by the osteoblast and continues to stimulate osteogenesis after the
calcium phosphate portion of the graft material has been converted into bone