Bone Grafting and Sinus Lift

When a graft comes into consideration

• The height or width of bone where the implant is planned is not enough
• In the back of the upper jaw the sinus sits low and there is no bone left for the length of the implant
• The socket is to be preserved in the same session as an extraction
• The ridge of the jaw has thinned where a tooth has been missing for a long time
• Gum disease has left a limited defect in the bone; not every defect can be grafted

When another step comes first

• Active infection and untreated gum disease. These are treated first.
• Uncontrolled medical conditions. If blood sugar is unstable or there is an undiagnosed problem, surgery is postponed.
• A jaw that is still growing. In young patients, implants and any graft for them are postponed until growth is complete.

What is associated with higher risk

The figures below come from studies of implant loss. We have no figure that measures graft success directly, and we say so plainly.

• Smoking. In people smoking more than 20 cigarettes a day, implant loss was about 2.5 times as likely per implant¹ as in non-smokers. Per patient it was about 4 times as likely. Smoking also impairs wound healing. No safe number of cigarettes has been shown.
• Bone-strengthening medicines. In a 21-study review, implant loss in people taking bisphosphonates was about 1.7 times more likely per implant². Jaw osteonecrosis was about 3.5 times more likely per patient. The per-patient analysis of implant loss found no significant difference. The same review could not make a reliable risk estimate for denosumab, so we give no figure for it. The certainty of the evidence is very low. For people taking high-dose bisphosphonates or denosumab as part of cancer treatment, surgery is usually not appropriate. Whether the medicine is given by drip, by injection or by mouth does not on its own decide the risk. The decision is made with your oncology team.
• Diabetes. The findings are mixed. Two of three reviews found no significant difference in implant loss (2021 review³; 2016 review⁴), and one found a higher rate⁵. The 2021 review, in type 2 diabetes, ties its result to strictly maintained oral hygiene. All three found more bone loss around implants in people with diabetes.
• A history of gum disease. Across 14 prospective studies the rate of implant loss was about 1.75 times higher⁶ (a hazard ratio). Surgery is not done while the disease is active.
• Radiotherapy to the head and neck. Wound healing is impaired in irradiated bone, and there is a risk of bone death. The area and dose of the radiotherapy are established, and planning is done with your oncology team.

What can be considered instead

• Short implants. A Cochrane review found that in a resorbed lower jaw, short implants appear to be a better option⁷ than a vertical bone graft. Case selection, bone quality and chewing forces are assessed.
• Tilted implants. In a jaw with no teeth, placing the back implants at an angle may reduce the need for a graft in some patients. The details are on the All-on-6 page.
• Zygomatic implants. When very little bone is left in the upper jaw, implants anchored in the cheekbone come into consideration. This is larger surgery with its own risks; it is explained at the consultation.
• A removable denture. If surgery is not wanted or not suitable, a denture is an option.

Suitability is decided by an examination, a 3D scan and your medical history. A plan given from photographs is not final; it is a preliminary assessment.

Sometimes. If there is enough bone, no graft is needed; and if there is not, a graft is not the only route. The options are considered in order: doing nothing extra, a design that needs less surgery, then a graft.

A sinus lift without graft material has also been reported. A review of 16 articles looked at implant survival over 48 to 60 months of follow-up. It was 96 per cent without graft material⁸ and 99.6 per cent with a biomaterial. The summary we could access reports no direct statistical comparison of these two rates. So the difference cannot be counted as a proven advantage, and nor can the opposite.

No single technique or material has been shown to be superior for every patient and every outcome. A Cochrane review states that the most effective technique remains unclear⁷. The same review reports differences in single comparisons, such as bone gain and patient preference. A review of sinus floor augmentation found no significant difference⁹ in implant loss between your own bone and bone substitutes. Finding no difference in implant loss does not mean the materials are equivalent in every respect. If a material is presented to you as "the best", ask for the reasoning on your own scan.

Where the graft material comes from is also part of your decision. It can be taken from your own bone or prepared from a human donor or an animal source (bovine or porcine). It can also be fully synthetic. Covering membranes can also be of animal origin. For some patients this is decisive, for religious or personal reasons. Before you consent, you are told which graft and which membrane will be used and where they come from. You are also told the alternatives, and whether they need to be removed later.

This is the usual sequence. Which method is chosen depends on the scan and the shape of the defect. The number of visits, the gaps between them and the waiting periods are given in your written plan; they vary from patient to patient.⁹

Risks

• A tear in the sinus membrane. The membrane often tears during a sinus lift. A review of 10 studies looked at sinus lifts through a side window with graft material. The average tear rate was 29.42 per cent¹⁰. The earlier studies it cites report 16 to 56 per cent. A tear is usually repaired in the same session. Depending on its size and how reliable the repair is, the procedure may be stopped and planned again once the membrane has healed. Implant survival was 97.1 per cent after a repaired tear and 97.7 per cent with no tear. The difference was not significant. Some of its studies describe problems after surgery, such as sinusitis. The review does not compare them between torn and intact membranes. So it does not show that a tear has no drawbacks.
• Complications with vertical augmentation. A Cochrane review of 13 randomised trials states that complications are common, especially with vertical augmentation. Compared with short implants, the odds ratio for complications was 4.97⁷. In the same review the difference in implant loss was not significant.
• Infection and the graft not taking. Infection can develop at the graft site, stitches can open and a membrane can become exposed. If that happens, part or all of the graft may be lost and the procedure may need to be repeated.
• Graft particles coming out. In the first weeks, small hard particles may come out through the gum. A bad smell, discharge or increasing pain may be a sign of infection.
• The donor site. If a block of your own bone is taken, a second surgical site is opened. It too brings pain, swelling and a scar.
• The sinus area in the upper jaw. Sinusitis, a nosebleed or an opening between the mouth and the sinus can develop. We have no sourced figure for how often these happen, and we say so plainly.
• The nerve in the lower jaw. Because the nerve canal is close in the back of the jaw, the lip and chin may feel numb for a while and, rarely, permanently.
• Medication-related death of jaw bone (osteonecrosis). In patients taking bisphosphonates, the risk of jaw osteonecrosis after surgery was found to be higher. The review cited on this page gives no reliable estimate for denosumab. If you take either medicine, always tell us your full medication history.

Benefits

• The aim is to increase bone volume so an implant may be placed in the planned position and at the planned length.
• Implant loss after sinus floor augmentation has been reported as low. In 11 prospective studies with at least five years of follow-up, annual loss was 0.43 per cent per implant⁹. In these studies the remaining bone height was 6 millimetres or less, and the side-window technique was used.
• The same review found no significant difference between your own bone and bone substitutes. Nor did it find a difference between placing the implant in the same session or later. Finding no difference does not show that the methods are equivalent for every patient; the findings are limited to the group of patients described above.
• Preserving the socket at the time of an extraction can help keep the later surgery smaller.

These rates are outcomes observed in studies, not promises. They are averages of studies from different countries and different groups of patients. What happens in your case depends on your bone, your habits and your care.

The first days

• Swelling and bruising increase over the first two to three days, then settle. Use cold packs and the medicines prescribed.
• Choose soft, lukewarm food, and avoid chewing on the graft site.
• If the sinus area was treated, do not blow your nose or drink through a straw, and if you sneeze, keep your mouth open. These rules reduce pressure changes on the sinus membrane.
• Keep brushing; clean the graft site gently, the way your dentist shows you.
• Smoking impairs healing. At the least, do not smoke during the healing period.
• If you had sedation, do not drive or operate machinery for as long as the sedation team tells you. For adults, every form of sedation other than inhaled sedation requires a responsible adult to take you home¹¹. If an escort cannot be arranged, treatment under sedation is not carried out. The discharge rules for your method are explained in advance. The details are on the conscious sedation page.

Later reviews

Follow-up after an implant is different from a general dental check-up. The 2017 consensus report recommends that an X-ray and probing measurements be taken as a baseline¹² when the crown or bridge is completed. Later changes are judged more reliably against that record. The NICE guideline on dental recall recommends that the review interval be set for each patient¹³, with three months as the shortest interval. That guideline is not specific to implants; a ready-made interval is not enough for a patient with implants.

A graft does not lengthen treatment by the same amount for every patient. There are two main routes. Small grafts done in the same session as the implant often add no separate waiting period; treatment moves on with the implant's own healing time. In a staged graft, the graft comes first and the bone is left to form; the implant is placed later. This route adds a separate waiting period. For sinus floor augmentation, no significant difference⁹ in implant loss was found between these two routes. That does not show the two routes are equivalent for every patient. How much longer it takes depends on the size of the defect, the method chosen and how you heal. The time expected for you is given in your written plan.

There are studies comparing early and later fitting of the teeth on implants. A Cochrane review of 26 randomised trials found no evidence of a difference¹⁴ in implant loss between immediate and conventional loading. Follow-up ranged from 4 months to 1 year, and most of the trials were at high or unclear risk of bias. This finding does not show that a whole treatment with a graft can be fitted into a few days. We have found no study comparing the whole grafting process compressed into a short period with treatment spread over months. The difference is judged by practical questions. How is healing checked? Who do you contact if there is a problem? Which aftercare is included in the plan?

Before treatment we give you, in writing, the route to follow if there is a complication and our remake terms. You can ask us for that document before you decide.

After surgery, contact your dentist if any of the following happens.

• Pain or swelling that increases after the third day, or bleeding that does not stop
• A high temperature, feeling unwell, or a bad smell and pus from the area
• Stitches opening, or the graft or membrane becoming visible through the gum
• Hard particles coming out continuously and in large amounts
• Discharge from the nose, a blocked nose or sinus pain on the treated side
• Liquid coming out of your nose when you drink, or air passing between your mouth and nose
• Numbness of the lip or chin that lasts beyond the expected duration of the anaesthetic

Emergencies. Difficulty breathing or swallowing, rapidly spreading swelling of the face or neck, or swelling around the eye with a high fever are serious signs. If you have any of them, do not wait for the clinic's reply. Go to the nearest emergency department or call 112.

This page does not quote fees. The main factors in a plan are these:

• The size and position of the defect
• The method chosen
• The type and amount of graft material
• Whether a membrane is used
• Whether a block of your own bone is taken
• Sedation
• The number of visits and the review programme

The plan also states what will be done if the graft does not take. Ask in writing what your plan includes, and who pays for further treatment if there is a complication.