Dental bone grafts are procedures done to replace missing bone in the jaw. They are often needed before getting dental implants placed. While bone grafts have a high success rate, failures can occur. If your bone graft failed, don’t worry – understanding why it happened is the first step to trying again.
Quick answers on why a dental bone graft may fail
There are a few key reasons why a dental bone graft may fail:
- Infection – If bacteria contaminated the graft site, it can lead to graft failure.
- Insufficient blood supply – The graft needs blood vessels to grow into the new bone. Poor blood supply will cause graft failure.
- Poor patient health – Medical issues like diabetes or smoking can impede healing and integration of the bone graft.
- Trauma – Physical trauma to the graft site early on disrupts the healing process.
- Improper graft storage – Bone grafts must be handled properly. Improper storage leads to poor bone quality.
- Incorrect surgical technique – Proper placement and fixation of the graft is crucial. Surgical errors can cause failure.
Common signs that a dental bone graft is failing
If you suspect your bone graft is not integrating as it should, look for these signs of failure:
- Persistent pain and swelling at the site weeks later
- Numbness or tingling in the chin, lips, or tongue
- Visible loss of bone graft material
- Increase in soft tissue over the graft site
- Looseness of stitches or graft material
- Signs of infection – redness, pus, foul odor
- Failure of the gum tissue to heal properly
See your dentist promptly if you notice any of these warning signs. Action can be taken to help salvage the bone graft procedure.
Why poor blood supply causes dental bone graft failure
Having adequate blood supply is critical for the survival and integration of a bone graft. Blood brings stem cells, nutrients, and growth factors to the graft site that are needed for new bone formation.
Here’s why poor blood supply leads to failure:
- Lack of blood vessels limits oxygen delivery to the graft, causing bone cell death.
- Nutrients cannot reach the graft which impedes bone matrix production.
- Waste products are not removed, creating a toxic environment for bone cells.
- Stem cells and growth factors cannot reach the grafted bone to stimulate regeneration.
- The graft cannot develop its own blood supply and will not integrate with surrounding bone.
Grafts with poor vascularization often resorb and disappear. Your dentist will assess blood supply at the planned graft site beforehand. Medications or hyperbaric oxygen treatment may improve blood flow.
Infection causes and prevention for dental bone grafts
Infection introduces bacteria to the graft site, triggering inflammation and bone loss. Here are infection causes and prevention tips:
Causes of bone graft infections
- Poor oral hygiene prior to surgery
- Existing tooth decay or gum infections
- Salivary contamination during surgery
- Bacteria on bone harvesting equipment
- Non-sterile surgical environment
- Foreign material reactions in the body
Preventing infections
- Get professional cleanings and treat any infections before surgery
- Use prescribed antibiotic rinses before and after surgery
- Avoid smoking before and after the procedure
- Follow all post-surgical care instructions carefully
- Do not submerge healing wounds in water
- See your dentist quickly if signs of infection develop
Why smoking causes dental bone graft failure
Smoking severely impacts the success of bone grafting in the jaw. The nicotine and hundreds of toxins in cigarette smoke have these detrimental effects:
- Constricts blood vessels – Reduces blood supply to the graft site
- Impairs immune function – Increases infection risk
- Damages osteoblasts – Bone forming cells cannot function properly
- Inhibits growth factors – Vital proteins for bone growth are blocked
- Promotes inflammation – The graft site cannot heal properly
- Increases free radicals – Causes bone cell damage and death
Studies show regular smokers have a 60-70% higher rate of dental implant and bone graft failures. Quitting smoking for 2 months before and after surgery is recommended.
Surgical mistakes that cause bone graft failure
While rare with experienced surgeons, errors during the bone graft procedure can lead to failure:
| Surgical Errors | Consequences |
|---|---|
| Poor graft positioning | Prevents blood supply formation; lacks stability |
| Suboptimal graft fixation | Movement disrupts integration with jawbone |
| Excessive periosteal stripping | Compromises blood supply to the graft |
| Overheating bone | Kills osteoblasts needed for bone growth |
| Incorrect graft size | Too large disrupts blood supply; too small lacks volume |
| Salivary contamination | Introduces oral bacteria; causes graft infection |
Find an experienced maxillofacial or periodontal surgeon with advanced training in bone grafting procedures.
Medical conditions causing dental bone graft failure
Your overall health impacts how well you heal after oral surgery. Medical issues that increase the risk of graft failure include:
Diabetes
- Poor blood sugar control impairs wound healing
- Microvascular disease reduces blood supply
- Greater infection risk due to high blood sugar
Autoimmune disorders
- Diseases like lupus cause chronic inflammation
- Medications weaken the immune system
- Grafted bone cannot integrate properly
Metabolic bone diseases
- Conditions like osteoporosis weaken jawbone density
- Medications may impede new bone formation
- Gradual bone graft breakdown over time
Inform your dentist about all medical conditions and medications. Optimal control of existing health issues is key.
Options after a failed dental bone graft
If your bone graft was unsuccessful, don’t lose hope. Here are some options to consider:
- Try again – Identify why the first graft failed and correct it before attempting another graft.
- Bone morphogenetic protein – Using BMP growth factor may stimulate better graft integration.
- Allograft bone – Donor bone has higher success in some graft failure cases.
- Guided bone regeneration – This can be done alone or along with graft material.
- Distraction osteogenesis – Bone is gradually stretched to expand a graft site.
- Jaw reconstruction – Large jaw defects may need plates, meshes, or bone flaps.
Talk to your oral surgeon thoroughly about expectations, success rates, recovery time, costs, and alternatives if you try another bone grafting procedure.
Conclusion
Dental bone grafts are highly technique-sensitive procedures. However, they fail in about 5-10% of cases for various reasons. Don’t get discouraged if your bone graft was not successful. Now that you know the common causes of failure, steps can be taken to improve the outcome next time. Identifying and addressing the reason for failure is key before attempting another bone graft. With proper planning and execution, there is a good chance bone grafting can still successfully prepare your jaw for dental implants.