Also called regenerative surgery, bone grafts are used to recreate bone and soft supporting tissues lost due to periodontitis. If you have periodontitis, you may be losing bone support around your teeth. After extractions, Dr. Nguyen may recommend regrowing the lost bone with a graft.
The goal of bone grafting is to encourage the body to rebuild the bone and other structures that attach a tooth to the jaw. Over the next few months, the grafted material will be encouraged to grow, which will fill in for lost bone and soft tissue.
Ridge Augmentation
A common use of bone grafting is for ridge augmentation. Ridge augmentation can recapture the natural contour of your gums and jaw after the loss of a tooth as a result of trauma, congenital anomalies, infection, or periodontal disease. Achieving an ideal amount of gum and bone as a support to surrounding restorations or implants may require hard and soft tissue reconstruction. After the loss of one or more teeth, your gums and jawbone may become indented where the tooth or teeth used to be. This occurs because the jawbone recedes when it no longer is holding a tooth in place. Not only is this indentation unnatural looking, it also causes the replacement tooth to look too long compared to the adjacent teeth, and this can create an area that is difficult to keep clean.
Ridge augmentation uses bone and tissue-grafting procedures to fill in the indented area of the jaw and gums, leaving you with a smooth gum line that coexists with your restoration or dental implant.
http://www.zimmerdental.com/Products/Regenerative/rg_overView.aspx
http://www.aaid-implant.org/dental-implant-options/bone-augmentation/
Mechanisms of Guided Bone Regeneration: A Review
Post-extraction crestal bone resorption is common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, Guided Bone Regeneration (GBR) is often required. GBR is a surgical procedure that uses barrier membranes with or without particulate bone grafts or/and bone substitutes. There are two approaches of GBR in implant therapy: GBR at implant placement (simultaneous approach) and GBR before implant placement to increase the alveolar ridge or improve ridge morphology (staged approach). Angiogenesis and ample blood supply play a critical role in promoting bone regeneration.