Bone Grafting and Guided Bone Regeneration
Advances in medicine and dentistry have led to new and expanded areas of treatment. Two such areas, bone grafting and guided bone regeneration (GBR) in the jaw bones and around teeth, have experienced tremendous growth. Procedures to repair and grow new bone are now part of routine dental surgical care.
What is bone grafting & guided bone regeneration (GBR)?
Bone grafting is a surgical procedure that replaces missing bone with a material called a bone graft. This material not only replaces missing bone, but also helps your body re grow lost bone. This new bone growth strengthens the grafted area by forming a bridge between your existing bone and the graft. Over time the newly formed bone will replace much of the grafted material. GBR is a procedure in which a membrane is placed over the bone graft site. This membrane further encourages new bone to grow and also prevents the growth of scar tissue in the grafted site.
Why are bone grafts & GBR needed?
Bone grafts & GBR are needed when a part of your body is missing bone. This missing portion of bone is frequently called a “bone defect”. Examples of jaw bone defects are: defects surrounding roots of teeth (periodontal defects); defects which occur following tooth extraction; generalized decrease in quantity of jaw bone from trauma or long-term tooth loss; defects surrounding dental implants; defects resulting from cyst or tumor surgery.
Are bone grafting & GBR painful procedures?
These procedures are usually done in the doctor’s office under local anesthesia or local anesthesia with I.V. sedation or occasionally general anesthesia. The procedures themselves are without pain. Post-operatively, there will be some swelling and some mild to moderate discomfort, especially from other procedures performed, such as tooth extraction, cyst removal, etc. Your doctor will prescribe an oral analgesic to help relieve your discomfort.
What special care is required after my grafting procedure?
Generally, the same prudent care required after any dental surgical procedure will be sufficient following jaw bone grafting & GBR. The area must be kept clean, often with the help of a prescribed mouth rinse. An antibiotic, if prescribed by your doctor, must be taken. Antibiotics, however, are not always required. Undue pressure over the grafted site must be avoided until new bone is well on its way to being formed. This means that previous dental prostheses, such as a removable full or partial denture, must be altered by your dentist following the grafting procedure. And finally, brush and floss you teeth as you normally do. However, avoid the gum tissues surrounding the bone graft until they are well healed (usually about six weeks).
How successful are bone grafting & GBR?
Recent advances in technology have dramatically increased the success of these procedures, leading to bone formation and resolution of the defect. However, depending upon the reason needed for these procedures, success rates vary. Also, different graft & GBR materials seem to affect the amount of new bone formed. And finally, your own overall health will also help determine the degree to which new bone will form within the grafted site.
Are there different types of bone grafts & GBR membranes?
Yes. Some grafts are taken from different parts of the patient’s own body (i.e. from the hip bone or chin). Other grafts come from deceased human organ donors, from synthetic materials, and from highly purified bone material. Likewise, there are different types of GBR membranes. Some are made from synthetic polymers and must be removed during a second surgery several weeks or months later. Others are made from natural materials and are gradually resorbed (melt away) by the body.
Types of Bone Grafts
Autogenous Bone Grafts:
Autogenous bone grafts, also known as autografts, are made from your own bone, taken from somewhere else in the body. The bone is typically harvested from the chin, jaw, lower leg bone, hip, or the skull. Autogenous bone grafts are advantageous in that the graft material is live bone, meaning it contains living cellular elements that enhance bone growth.
However, one downside to the autograft is that it requires a second procedure to harvest bone from elsewhere in the body. Depending on your condition, a second procedure may not be in your best interest.
Allogenic bone, or allograft, is dead bone harvested from a cadaver, then processed using a freeze-dry method to extract the water via a vacuum. Unlike autogenous bone, allogenic bone cannot produce new bone on it’s own. Rather, it serves as a framework or scaffold over which bone from the surrounding bony walls can grow to fill the defect or void.
Xenogenic bone is derived from non-living bone of another species, usually a cow. The bone is processed at very high temperatures to avoid the potential for immune rejection and contamination. Like allogenic grafts, xenogenic grafts serve as a framework for bone from the surrounding area to grow and fill the void.
Both allogenic and xenogenic bone grafting are advantageous in that they do not require a second procedure to harvest your own bone, as with autografts. However, because these options lack autograft’s bone-forming properties, bone regeneration may take longer than with autografts, with a less predictable outcome.
Bone Graft Substitutes:
As a substitute to using real bone, many synthetic materials are available as a safe and proven alternative, including:
Demineralized Bone Matrix (DBM)/Demineralized Freeze-Dried Bone Allograft (DFDBA):
This product is processed allograft bone, containing collagen, proteins, and growth factors that are extracted from the allograft bone. It is available in the form of powder, putty, chips, or as a gel that can be injected through a syringe.
Graft composites consist of other bone graft materials and growth factors to achieve the benefits of a variety of substances. Some combinations may include: collagen/ceramic composite, which closely resembles the composition of natural bone, DBM combined with bone marrow cells, which aid in the growth of new bone, or a collagen/ceramic/autograft composite.
Bone Morphogenetic Proteins:
Bone morphogenetic proteins (BMPs) are proteins naturally produced in the body that promote and regulate bone formation and healing.
Synthetic materials also have the advantage of not requiring a second procedure to harvest bone, reducing risk and pain. Each bone grafting option has its own risks and benefits. Drs. Davis or Cramer will determine which type of bone graft material is right for you.