Bone grafting is often closely associated with dental restorations such as bridge work and dental implants. In the majority of cases, the success of a restoration procedure can hinge on the height, depth, and width of the jawbone at the implant site. When the jawbone has receded or sustained significant damage, the implant(s) cannot be supported on this unstable foundation and bone grafting is usually recommended for the ensuing restoration.
There are several major factors that affect jaw bone volume:
Periodontal Disease – Periodontal disease can affect and permanently damage the jaw bone that supports the teeth. Affected areas progressively worsen until the teeth become unstable.
Tooth Extraction – Studies have shown that patients who have experienced a tooth extraction subsequently lose 40-60% of the bone surrounding the extraction site during the following three years. Loss of bone results in what is called a “bone defect”.
Injuries and Infections – Dental injuries and other physical injuries resulting from a blow to the jaw can cause the bone to recede. Infections can also cause the jaw bone to recede in a similar way.
Reasons for bone grafts
Bone grafting is a highly successful procedure in most cases. It is also a preferable alternative to having missing teeth, diseased teeth, or tooth deformities. Bone grafting can increase the height or width of the jawbone and fill in voids and defects in the bone.
There are essentially two basic ways in which bone grafting can positively impact the health and stability of the teeth:
Jaw Stabilization – Bone grafting stabilizes and helps restore the jaw foundation for restorative or implant surgery. Deformities can also be corrected and the restructuring of the bone can provide added support.
Preservation – Bone grafting can be used to limit or prevent bone recession following a tooth extraction, periodontal disease, or other invasive processes.
Initially, the dentist will thoroughly examine the affected area in order to assess the general condition of the teeth and gums. If periodontal disease is present or the adjacent teeth are in poor condition, these factors will be fully addressed before the bone grafting procedure can begin. The dentist will also recommend panoramic x-rays in order to assess the precise depth and width of the existing bone. On occasion, a CAT scan may be recommended to determine the bone condition. Depending on these results, the dentist may also anaesthetize the area and explore into the gum in order to determine what kind and how much bone is required.
What Does Bone Grafting Involve?
There are several types of bone grafts. Your dentist will determine the best type for your particular condition.
Autogenous Bone Graft - Harvested from the patient’s own body (usually from the posterior part of the lower jaw or the chin). This method is usually preferred because it produces the most predictable results.
Allograft Bone Graft - Cadaver or synthetic bone is used in this type of graft.
Xenograft - Cow bone is used in this type of graft.
The bone grafting procedure can often take several months to complete. Bone is typically harvested from your own body (or on rare occasions obtained from a “bone bank”) and added to the affected site. This bone will fuse with the existing bone and the migration of cells will cause firm adhesion and cell growth. Supplementing the jaw with bone will result in greater bone mass to help support and anchor the implant(s).
During the surgery, the dentist will numb the grafting and extraction sites using local anaesthetic. A small incision will be made to prepare the site for the new bone and it will be anchored into place. On occasion, a synthetic membrane may be used to cover the new bone. This membrane prevents soft tissue and bacterial invasions, and encourages new bone growth. The surgery does not require an overnight stay, and you will be provided with comprehensive instructions for your post-operative care. The dentist will prescribe medications to help manage infection, discomfort and swelling.