Bone Graft Materials for Dental Implants: Your Own Bone, Donor, Bovine or Synthetic

In the Austin area? Dr. Verrett provides this care in North Austin. See Bone Grafting for Dental Implants, or request a consult.

A patient told that an implant needs a bone graft usually has two questions straight away. Where does the bone come from? And does it matter? The answers involve four kinds of material, a blood product, and a body of research that is more reassuring than most patients expect. This article sets out what each material is, what the trials show, and how the choice is made for a particular site.

Why a Graft Is Needed at All

An implant needs bone around it on every side. After a tooth is removed, the bone that held it begins to shrink. A systematic review by Tan and colleagues found that an extraction socket left to heal on its own loses roughly 29 to 63 percent of its width and 11 to 22 percent of its height in the first six months. Gum disease, infection, an injury, or a tooth missing for years can leave even less.

A graft does one of three jobs:

• Socket preservation. Filling a socket at the time of extraction, so the ridge keeps more of its shape while it heals.
• Ridge augmentation. Rebuilding a ridge that has already shrunk, in width, height, or both.
• Sinus lift. Adding bone beneath the sinus in the upper back jaw, where the sinus often expands into the space an implant needs. Sinus lift covers that procedure in detail.

In each case the graft material is a scaffold. The patient’s own bone cells do the work of growing into it. What differs between materials is how they support that process and how long they last.

The Four Kinds of Graft Material

The Patient’s Own Bone (Autograft)

Bone taken from elsewhere in the patient’s body, usually from inside the mouth: the back of the lower jaw, the chin, or small shavings collected near the surgical site. It contains living cells and natural growth signals, which is why it has long been called the “gold standard.”

It works well. In a review of 279 consecutive patients who had 456 grafting procedures using their own bone, Sakkas and colleagues found that 95.6 percent of grafts healed successfully, and 99.6 percent of the implants placed were still in place two years after the teeth were attached.

The cost is a second surgical site. Taking bone from the chin, for example, can affect the feeling of the chin and the lower front teeth. In a prospective study of 20 patients, Nkenke and colleagues found that 8 had altered sensation in the chin a week after harvest, and 2 still had numbness on one side of the chin at 12 months. At 12 months, 11.4 percent of the lower front teeth examined no longer responded normally to a cold test. The authors concluded that patients should be told about these risks in detail before chin harvesting. The back of the lower jaw is a more common donor site in dentistry today, but any second site adds time, discomfort and risk.

Processed Human Donor Bone (Allograft)

Bone from a human donor, supplied by a regulated tissue bank. Donors are screened, and the bone is cleaned, processed and sterilized so no living cells remain. What is left is the mineral and protein framework of bone.

Patients reasonably ask about the safety of a donor material. The most widely cited estimate comes from Buck and colleagues in 1989, who calculated that with rigorous donor selection, testing and tissue examination, the chance of receiving bone from an HIV-infected donor was one in well over a million. They also warned that inadequate screening could raise that risk sharply, which is why the source of the material matters. Screening methods have improved considerably since 1989.

Processed Bovine Bone (Xenograft)

The mineral portion of cow bone, with all the organic material removed, leaving a porous mineral scaffold very similar in structure to human bone. It has been used in dental grafting for decades.

Its defining feature is that it resorbs very slowly. Biopsies taken by Mordenfeld and colleagues 11 years after sinus grafts, using a mixture that was 80 percent bovine bone and 20 percent the patient’s own, showed the bovine particles well integrated in mature bone and unchanged in size compared with six months after surgery. That slow turnover is an advantage where a graft must hold its shape for years, such as the thin bone on the cheek side of a front tooth, or beneath the sinus.

Synthetic Mineral (Alloplast)

Manufactured calcium-phosphate minerals, made to resemble the mineral of bone. They involve no human or animal source, which makes them an option for patients who prefer to avoid one for religious, ethical or personal reasons.

Does the Material Change the Result?

This is the question that matters most to patients, and the evidence is consistent: for implant survival, the material makes less difference than people expect.

Socket preservation. The 2021 Cochrane review by Atieh and colleagues included 16 randomized trials covering 524 extraction sites. Grafting a socket with bovine bone limited the loss of ridge width by about 1.2 millimeters and of height by about 1.4 millimeters compared with extraction alone, although the certainty of that evidence was rated very low. The review found no evidence of a clinically significant difference between the grafting materials themselves, and not enough long-term data to show differences in implant failure.

Sinus lifts. The 2014 Cochrane review by Esposito and colleagues included 18 randomized trials and 650 patients. It found insufficient evidence that the patient’s own bone gave better results than a bone substitute, and no sinus lift technique reduced implant or prosthesis failure compared with any other. Looking at longer follow-up, a meta-analysis by Starch-Jensen and colleagues found five-year implant survival of 97 percent with the patient’s own bone and 95 percent with bovine bone, with similar loss of graft height over time. The authors cautioned that no long-term randomized trial had compared the materials directly.

Sinus lifts and ridge rebuilding together. A meta-analysis by Al-Nawas and Schiegnitz found mean implant survival of 98.6 percent with bone substitutes and 97.4 percent with the patient’s own bone in sinus lifts, and concluded there was no evidence that the patient’s own bone is superior to substitutes. They noted that the studies described the size of the defects poorly, which limits how far the finding can be pushed.

Larger rebuilds. For rebuilding a ridge that has shrunk in width or height, the 2009 Cochrane review by Esposito and colleagues found that various techniques can add bone but that it was unclear which is most efficient. It suggested that some bone substitutes could be a preferable alternative to the patient’s own bone, and found that patients preferred a substitute block over a block taken from the hip. It also found that complications are common with vertical rebuilding in particular. The review was based on few trials with few patients, and its authors said so.

On current evidence, implants placed in grafted bone do about equally well whichever material is used. The differences between materials are mostly about handling, how long the graft holds its shape, and whether a second surgical site is needed.

What PRF Adds

Platelet-rich fibrin, or PRF, is made from a small sample of the patient’s own blood, drawn at the start of the visit and spun in a centrifuge until a fibrin clot carrying platelets and white cells forms. It is added to a graft or placed in a socket to support healing. Nothing foreign is added to it.

The evidence is encouraging but not settled:

• In sockets. A 2023 meta-analysis by Caponio and colleagues, pooling 8 randomized trials and 250 patients, found that platelet concentrates placed alone in extraction sockets produced more new bone, measured under the microscope, than sockets left to heal on their own.
• With bone grafts and sinus lifts. A systematic review by Castro and colleagues found reports of faster bone healing when PRF was added to bovine bone in sinus lifts, but the trials were too varied to pool into a meta-analysis. The authors concluded that, despite the lack of strong evidence, PRF might have a positive effect on bone regeneration.
• The professional view. The American Academy of Periodontology’s 2022 consensus statement on biologics concluded that appropriately used biologics, including blood-derived products such as PRF, are generally safe and add benefit to conventional treatment. It also stated that evidence is limited for socket preservation and implant site development specifically.

“Sticky bone” is a related idea: graft particles mixed with a fibrin concentrate so they bind into a moldable mass that stays where it is placed. In a randomized trial of 28 patients having front-tooth ridges rebuilt, the sticky-bone group kept more of the grafted volume and reported less pain at one week than patients whose particles were mixed with saline. That is one small trial, and it is not yet enough to call the approach proven.

The fair summary is that PRF is a reasonable addition that may help and is unlikely to harm. It is not a reason to expect a different kind of result from the graft.

How the Choice Is Made

The right material depends on the site, not on a general ranking. The main considerations:

• The size and shape of the defect. A socket with all its walls intact needs little more than a scaffold that holds space. A ridge that has lost much of its width or height, especially in the front of the mouth, may call for the patient’s own bone, sometimes as a block fixed with small screws, or for particulate graft held under a membrane.
• How long the graft must hold its shape. Where the bone is thin and resorption would show, such as the cheek side of a front tooth, a slowly resorbing material like bovine bone is often chosen, alone or mixed with other material.
• Whether a second site is worth it. Taking the patient’s own bone adds a surgical site. For most socket grafts and many sinus lifts, the evidence above suggests a substitute will do as well without it.
• The patient’s preferences. Some patients prefer to avoid human or animal-derived material. Synthetic minerals and the patient’s own bone are alternatives, and this should be raised at the consult.
• Health and habits. Smoking affects grafts and implants alike. A meta-analysis of 107 studies by Chrcanovic and colleagues found that implants placed in smokers failed at 6.35 percent against 3.18 percent in non-smokers. Diabetes control and how well the area can be kept clean also matter.

A cone-beam CT scan, a 3D X-ray, shows the width and height of the ridge and the position of the sinus and nerve before surgery, which is how the size of the graft is planned. Am I a candidate for a dental implant? covers the other factors that shape an implant plan.

Timing: Graft First, or Graft and Implant Together?

A small graft to thicken bone around a new implant can often be placed at the same visit as the implant. A larger rebuild is done first and left to heal before the implant goes in. As a general guide, a grafted socket heals in about three months, and a larger ridge or lateral sinus graft in four to six months. How long does a dental implant take? walks through the whole sequence.

Questions Worth Asking

• What material are you planning to use for my graft, and why that one for this site?
• Will you need to take bone from anywhere else in my mouth?
• Can the implant be placed at the same visit, or does the graft need to heal first?
• I would prefer to avoid human or animal-derived material. What are my options?
• Will PRF be used, and what do you expect it to add?
• What happens if the graft does not take?

How This Office Approaches It

Dr. Andrew Verrett is a Diplomate of the American Board of Periodontology and the only doctor at Austin Periodontal Associates in North Austin. He uses graft materials with long track records: processed human donor bone, bovine bone mineral, synthetic mineral, and the patient’s own bone when the site calls for it. A resorbable membrane usually covers the graft, and PRF, made from a blood draw Dr. Verrett takes himself at the start of the visit, is used in most grafts. Patients who prefer to avoid human or animal-derived materials should say so at the consult; alternatives exist. Ridges are rebuilt with particulate grafts rather than bone blocks; block graft or particulate ridge augmentation? explains why. An anti-inflammatory is usually prescribed afterward, and antibiotics when the case calls for them. Bone grafting for dental implants describes the procedure and recovery. Request a consult or call (512) 346-6097.