Quick answer
Most dental bone grafts heal without a serious complication, but risks include infection, membrane exposure, bleeding, nerve injury, sinus perforation, graft resorption and failure. Smoking, uncontrolled diabetes, active infection and poor blood supply raise the risk. Revision surgery is possible but adds cost and time.
At a glance
- Common
- Swelling, bruising, soreness, minor bleeding
- Less common
- Infection, membrane exposure, suture breakdown
- Site-specific
- Nerve injury (lower jaw), sinus perforation (upper jaw)
- Higher risk
- Smoking, diabetes, infection, prior radiation
- Revision
- Possible; a new surgical fee, sometimes discounted
Bone grafting is a common procedure with a good safety record, but “common” is not “risk-free.” The risks fall into three groups: the ordinary aftermath that is expected, the complications that need treatment, and the site-specific dangers that depend on where the graft is placed.
Expected aftermath
These are not complications unless they persist or worsen:
- Swelling for two or three days.
- Bruising on the cheek or jaw.
- Soreness and a dull ache.
- Minor bleeding for the first day.
- Tightness around the sutures.
- A soft diet for a week.
Complications that need treatment
Infection
Infection can develop in the graft or the soft tissue. Risk factors include an infected site before surgery, a exposed membrane, smoking, diabetes and poor hygiene.
Signs: increasing pain after day three, pus, fever, spreading swelling, a bad taste.
Treatment: antibiotics, drainage, removal of infected material, or graft removal if the infection cannot be controlled.
Membrane exposure
A barrier membrane can become exposed through the gum. A small exposure may heal with local care; a large one can become contaminated and compromise the graft.
Signs: a white or grey patch, a visible membrane, a bad taste, discomfort.
Treatment: monitoring, adjustment, antibiotics, or early removal of the membrane.
Suture line breakdown
The gum can pull apart, especially if there is tension or the patient chews on the site. A small gap may heal; a large one may need re-suturing.
Bleeding
Persistent bleeding is uncommon but can happen, especially in patients on anticoagulants or with uncontrolled blood pressure. Bite on gauze and call the office if it does not stop.
Graft resorption or insufficient bone
The graft may resorb more than expected or fail to produce enough bone for the implant. This is often discovered at the imaging check. A revision may be needed.
Site-specific risks
Lower jaw: nerve injury
The inferior alveolar nerve runs through the mandible and supplies sensation to the lower lip, chin and teeth. Surgery near the nerve can cause:
- Temporary numbness or tingling.
- Altered taste.
- Rarely, permanent numbness.
A cone-beam CT and careful surgical planning reduce the risk but do not eliminate it.
Upper jaw: sinus perforation
The maxillary sinus sits above the upper back teeth. A sinus lift can tear the Schneiderian membrane. Small tears are usually repaired; large tears may require abandoning the graft and retrying later.
Other sinus risks: infection, sinusitis, bleeding, graft displacement.
Chin donor site
A block graft from the chin can cause numbness of the lower lip or chin, contour change and discomfort. Most numbness resolves, but some is prolonged.
Who is at higher risk
- Smokers.
- People with uncontrolled diabetes.
- People with active periodontal or sinus infection.
- People who have had radiation to the jaw.
- People taking bisphosphonates or denosumab.
- People on immunosuppressants or long-term steroids.
- People with poor oral hygiene.
- People who cannot follow aftercare instructions.
Tell the surgeon about all medications and medical conditions. Some risks can be reduced by changing the plan; others mean a different treatment is safer.
How to reduce risk
- Stop smoking before surgery and during healing.
- Control blood glucose.
- Treat active infection first.
- Get a cone-beam CT for complex sites.
- Choose a clinician who performs the procedure regularly.
- Follow aftercare exactly.
- Attend follow-up visits.
- Report symptoms early rather than waiting.
Revision surgery
If a graft fails, a revision may be possible. It usually means:
- Waiting for the site to heal.
- Re-assessing with imaging.
- A new graft, sometimes with a different material or technique.
- A new surgical fee, sometimes discounted by the original practice.
Ask about the revision policy before the first surgery. A practice that will not discuss it is a practice to question.
The bottom line
Most bone grafts heal well. The risks that matter are infection, membrane exposure, nerve injury in the lower jaw, sinus perforation in the upper jaw and graft failure. Smoking, diabetes and active infection are the main modifiable risk factors.
For the warning signs, read bone graft failure signs. For aftercare, see bone graft recovery.
Frequently asked questions
What is the most common complication of a bone graft?
Swelling, bruising and soreness are expected rather than complications. Among true complications, infection, membrane exposure and suture line breakdown are the most common. Serious complications such as nerve injury or sinus perforation are less common but matter more.
Can a bone graft get infected?
Yes. Infection can develop in the graft or the surrounding tissue, especially if the site was infected before surgery, the membrane is exposed or hygiene is poor. Signs include increasing pain, pus, fever and swelling after the first few days. Treatment may include antibiotics, drainage or graft removal.
Can a bone graft damage a nerve?
In the lower jaw, the inferior alveolar nerve runs close to the roots of the back teeth. Surgery, implants or grafting near it can cause temporary or, rarely, permanent numbness of the lip, chin or tongue. A cone-beam CT helps the surgeon plan around the nerve.
What happens if the sinus membrane is perforated?
A small perforation is often repaired during surgery with a membrane or suture. A large tear may require abandoning the graft and trying again later. Your surgeon will tell you if it happened and what it means for the timeline.
Can a bone graft fail?
Yes. The graft can resorb, fail to consolidate, become infected or produce insufficient bone. Failure does not necessarily mean the implant is impossible; a revision graft may be an option, but it adds time and cost.
Is a bone graft riskier than an implant?
They carry overlapping risks. A graft is often done before an implant, so the risks add up rather than compete. A graft in the lower jaw near the nerve or the upper jaw near the sinus has site-specific risks that a straightforward implant may not.