When do you need bone grafting before an implant? The types of graft and how it is done

Why does the jawbone shrink after a tooth is lost?

The jawbone keeps its volume as long as it receives chewing forces through the roots of the teeth. When a tooth is lost, the bone at that spot loses this stimulus and begins to shrink in width and height; the loss is fastest in the first months after the loss and then continues slowly for years.

Other causes speed it up: chronic gum disease, a removable denture pressing on the ridge for years, a difficult extraction, or infection at the tip of the root. That is why two people who lost the same tooth at the same age can have very different bone.

How do we know you need bone grafting?

By eye and on an ordinary X-ray it cannot be judged accurately. A 3D CBCT scan shows the width, height and density of the bone and the position of the nerves and the sinus to the millimetre, and on it we decide whether the implant can be placed directly or the bone must be built first.

The decision is not always a simple yes or no. Sometimes a small graft done in the same session as the implant is enough; sometimes a larger graft has to come first as a separate stage. The size and location of the deficit decide.

Types of bone graft

• Your own bone: taken from another site in your mouth, the reference for biological compatibility.
• Processed human bone: from certified bone banks, treated and sterilised, providing a scaffold on which your body builds its own bone.
• Processed animal bone: usually of bovine origin, treated to remove all organic components, slow to resorb and so good at holding volume.
• Synthetic materials: laboratory-made compounds similar to the mineral of bone.

These materials are often combined, and the graft is covered with a membrane that guides bone growth and stops gum tissue from filling the space before the bone does. This is called guided bone regeneration.

How the procedure is done

It is done under local anaesthesia at the clinic, with sedation added for anyone who feels anxious. Part of the gum is opened, the graft is placed where the bone is missing, then it is covered with the membrane and the gum is stitched over it.

Afterwards, mild to moderate swelling for a few days is expected, eased with cold compresses and the prescribed medication. The implant is placed later, once the graft has healed and fused with your bone; the dentist sets that interval according to the type and size of the graft, and confirms it with a scan before the next step.

What affects its success

• Stopping smoking, or reducing it as far as possible, before the procedure and during healing.
• Keeping diabetes and any chronic condition under control, in coordination with your physician.
• Oral hygiene and following the mouthwash and care instructions.
• Not pressing on the area with a removable denture during healing.
• Attending follow-up visits, even when you feel nothing.