Bone grafting and sinus lifts: when you need them
"You don't have enough bone for implants" isn't always the end of the road. Here's why bone is lost, and how it can often be rebuilt.
Why bone matters
A dental implant needs to be surrounded by healthy bone to be stable and last well. Enough height and width of bone also allows the implant to be placed in the right position, so the final tooth looks natural and is easy to clean.
Why bone is lost
The bone that holds your teeth is maintained partly by the teeth themselves. When a tooth is lost, that bone gradually shrinks, with much of the change happening in the first months. Other causes include:
- Gum disease, which destroys the bone supporting the teeth.
- Long-term denture wear, which can speed up bone shrinkage.
- Infection, cysts or difficult extractions.
- Injury to the face or jaw.
In the upper back jaw there's an extra factor: the maxillary sinus, an air space above the roots of your upper back teeth. After those teeth are lost, the sinus can expand downwards, leaving very little bone beneath it.
How we assess your bone
A 3D CBCT scan shows exactly how much bone is available, its quality, and where important structures like nerves and sinuses are. From this I can plan whether an implant can be placed straight away, whether grafting is needed at the same time, or whether it's better done as a separate first stage.
Types of bone grafting
Socket preservation
Graft material is placed into the socket at the time a tooth is removed, to help limit shrinkage and keep future implant options open.
Guided bone regeneration
Granules of graft material are placed where bone is thin and covered with a protective membrane. It's often done at the same time as placing the implant.
Block grafting
For larger defects, a small block of bone is fixed in place to rebuild width or height. Once it has healed, usually after several months, the implant can be placed. This is one of the advanced techniques I teach to other dentists.
What is a sinus lift?
A sinus lift creates room for an implant in the upper back jaw. The thin lining of the sinus is gently lifted and graft material is placed underneath, adding height to the bone. There are two main approaches:
- Internal (crestal) sinus lift: used when a small amount of extra height is needed, working through the site where the implant will go.
- Lateral window sinus lift: used when more height is needed, through a small access window in the side of the jaw.
Depending on how much bone there is to begin with, the implant may be placed at the same time or after a period of healing.
What are grafts made from?
Graft materials may come from your own bone, from carefully processed donor or animal sources (commonly bovine), or be synthetic. Each has pros and cons, and I'll explain which I'd recommend for you and why.
Recovery
Grafting is done under local anaesthetic, with sedation if you'd like. Afterwards, swelling and some bruising are common for a few days, and are usually well controlled with painkillers and cold compresses. After a sinus lift, you'll also be asked to:
- Avoid blowing your nose for around two weeks.
- Sneeze with your mouth open to avoid pressure on the sinus.
- Avoid flying, diving and strenuous exercise until you've been advised it's safe.
Grafts need time to mature, and healing commonly takes several months before an implant can be placed or restored. It's a longer road, but it can make implants possible for people who'd previously been told they weren't suitable.