Dental Bone Grafting
Dental Bone Grafting
Dental bone grafting is a periodontal surgery procedure used to help the body regenerate new bone by replacing missing bone with a bone graft. Bone grafting is commonly used to provide adequate bone mass surrounding a dental implant in order to help osseointegration and deliver sufficient strength and stability.
Types of Bone Grafting procedures
The procedure, also known as bone augmentation, can be used to replace missing bone in different areas of the mouth.
There are 3 different types of bone graft procedures used to build bone so that implants can be placed:
- extraction site bone graft - bone grafts in the socket of the extracted or lost tooth are the most common type. This is where the implant will be placed and the jawbone must have sufficient quality and quantity.
- sinus lift - sinus lift bone grafts aka sinus augmentation are a special type of dental implant bone grafts sometimes required when placing upper jaw implants. This procedure affects the maxillary sinuses which are located just over the molar teeth in the upper jaw. If there is not enough bone depth below the sinus cavity, the sinus membrane must be lifted and a bone graft must be placed in this area. Read more about sinus lift procedure.
- ridge augmentation - After tooth extraction the ridge may become narrow and sharp not allowing the placement of dental implants. Ridge augmentation is a procedure where bone grafts are used to increase the bone ridge width and/or height.
How a bone graft works?
During the body's normal operation, specialized cells in the blood continually remove damaged cells from the various body tissues (osteoclasts) and replace them with new, healthy cells (osteoblasts). Bone grafting procedure takes advantage of this process, by providing a framework of graft material in the areas of missing bone into which these cells can enter and start creating new bone.
Dental implant bone grafts can help the build up of new bone with 3 different mechanisms:
- osteogenesis, the formation of new bone by the cells contained within the graft
- osteoinduction, a chemical process in which molecules contained within the graft (bone morphogenetic proteins) make the patient's cells capable of forming new bone
- osteoconduction, a physical effect by which the matrix of the graft forms a scaffold on which patient's can form new bone.
The process is referred as Guided Bone Regeneration (GBR) when bone grafts are placed in combination with biocompatible barrier membranes that keep out gum tissue and allow the bone growth.
Timing of the dental implant bone graft surgery
The time that the bone graft procedure is performed depends on the individual's treatment plan prepared by the implant dentist. Dental implant bone grafting can take place:
- before the implant placement - if the dentist has identified with the help of x-rays or CT-scans that there is not enough jawbone to support the implant, he will plan first the bone grafting procedure. The surgical procedure for the placement of dental implants has to be delayed for several months until there is adequate bone build up at the implantation area.
- during the implant placement - sometimes the bone grafting is made during the same surgical procedure. If the condition of the jawbone is marginal, the dentist may decide to place a bone graft along with the implant to decrease the risk of failure. Sometimes x-rays fail to reveal a jawbone problem which is revealed only when the bone is exposed during surgery. If the problem is not severe, the dentist will perform a bone graft and place the implant in the same surgical phase. Otherwise the implant placement has to be postponed.
- after tooth extraction (preventive bone grafts) - a dentist may recommend a bone graft immediately after a tooth extraction even if an implant procedure is not yet decided. The bone graft can preserve existing bone tissue and by stimulating new bone creation in the socket can provide a suitable environment for placing a dental implant in the future. The procedure is also referred as 'Ridge Reservation'.