When is Bone Grafting Necessary?
Over time, the areas of the jawbone where teeth are missing slowly breaks down or sinks in. This normal process often leaves an area unsuitable for rehabilitation with dental implants or other forms of restoration either because there isn’t enough of the jaw bone left or the bone is of poor quality. In these scenarios, bone grafting is performed to repair or build back up the bone quantity and quality in order to allow for complete rehabilitation with fixed or removable dentures (prosthesis).
After bone grafting, reconstruction with dental implants or other forms of restoration may then restore functionality and aesthetic appearance. There are several different types of bone grafting based upon the timing, volume, and methods used.
Types of Bone Grafting
Site/Socket Preservation Grafts
Immediately following the extraction of a tooth, the healing process begins with the formation of a blood clot in the area, and over time, this blood clot slowly forms into bone by the body’s natural healing process. In order to avoid contraction or the collapsing of the hole created by the missing tooth, which can occur during the healing process and leads to an unfit restoration site, site preservation grafts are done at the time of tooth extraction.
- Tooth is extracted
- Site is cleansed appropriately
- Particulate graft material is packed into the socket to completely fill the site
- Graft material acts as a volume maintainer to help prevent contraction by filling the hole
- Serves as a scaffold used by the body’s cells to regrow bone in a predictable and efficient manner
After approximately 3 months of healing, the site may be ready for dental implants and reconstruction. Site preservation grafts are recommended for any patient having a tooth extraction and is also considering reconstruction, especially those considering dental implants.
If a tooth has been missing in an area, eventually the jawbone begins to waste away leaving a defect that cannot be reconstructed. Particulate grafts are a method used to restore the areas of the bone that have wasted away using a powder or particulate grafting material.
- Site is exposed and prepared for the material to be packed into the area
- Graft material may be taken off the shelf or taken from the patient; however, pre-packaged powder is more commonly used
- Once an adequate volume is placed in the area, the graft is covered and the area is closed using sutures (stitches)
A period of healing is allowed to occur before any dental implants or other form of restoration is done, taking approximately 4-6 months.
Block Bone Grafting
Block bone grafting is another method of repairing a site where teeth have been previously lost. Typically, this method is used in cases of larger defects than in those where particulate graft procedures are adequate. In these cases, a larger piece of bone is removed from the patient and used in the area of bone loss.
Over a period of 3-6 months, the graft is incorporated into the jaw bone to improve the bone quantity and quality for eventual dental implant placement or other restoration procedures. The sites that are typically used as a source for this type of graft include the chin or third molar region of the lower jaw.
Particulate vs. Block Bone Grafting
A common question that arises in oral surgery is when particulate grafts or block type bone grafts should be used. Each case is unique and should be approached in that manner; therefore, no blanket answer is possible. However, for small defects, particulate grafts often serve the purpose and avoid creating a second surgical site for removing the graft material. Larger defects are predictably treated with block grafts; yet, a factor to consider involves creating a second surgical site to remove the block, which carries with it symptoms of post-operative discomfort and swelling. For the most part, healing rates are essentially equivalent, along with the quality and quantity of resulting bone.
Major Bone Grafting (Large Volume Grafting)
In situations of significant trauma or pathological conditions, larger volumes of bone grafting are required to build up the jaw bone enough to allow for dental implant placement or other restoration procedures. In these cases, particulate and block bone grafting techniques are inadequate for the amount of bone required for eventual rehabilitation. Larger, more involved grafting procedures are planned in these situations, and the grafts may be taken from the patient’s hip, calvariam, or tibia.