If you do not have enough bone what can be done?
So far we have covered the building blocks that are part of routine implant placement. This has included the initial examination and diagnosis, special x-rays such as CBCT scans, sedation during surgery and what to expect after the implants have been placed. However, for some people, bone loss after the removal or loss of teeth leaves them without enough to secure an implant. There are procedures that can be done if this is the case:
- In the upper jaw above the back teeth, it is possible to increase the height of bone available by creating new bone in the sinus. This procedure is called a ‘sinus augmentation’. A skilled surgeon can deliver highly predictable results in this location and without the general success of this technique many patients would be unable to have implants in a part of the mouth where teeth are so commonly missing.
- There are many ways in which bone can be added; however, one simple concept is to take a piece of bone from somewhere else and secure it as an ‘onlay graft’ to a deficient area. The new piece of bone will slowly join to the underlying region and when healed and mature, an implant can be placed in a more favourable position.
Where can you get extra bone from?
Bone can be harvested from a number of sources but usually from behind the back teeth in the lower jaw or from the chin. Sometimes it is taken from the hip or shinbone (tibia). When you use your own bone to create new bone in another area of the mouth you will have to contend with the discomfort created by the donor site as well as the surgical site. Many people feel this is well worth any additional discomfort as your own bone is normally considered the ‘gold standard’.
Alternatives to your own bone for grafting
For those who would prefer an easier but slightly slower, solution there are other sources of bone such as bovine (derived from cow), porcine (derived from pig) or synthetic materials that have been specially prepared to make them safe for use in humans. All of these materials, including your own bone, simply provide a scaffold into which new bone will grow in order to be ready to receive dental implants a few months later.
New bone can take anything from 3 to 12 months before it is ready to receive dental implants. Do not be in a hurry to move to the next stage. If you need a large volume of bone it will take longer to mature than a small amount.
Each surgeon will have his or her preferred way of creating new bone. Many of them will also use a supplementary technique called ’guided tissue regeneration’. Using this technique, slow-moving bone cells are given time to fill a space by placing a barrier material between them and the fast moving cells of the soft tissues lining the mouth. This is a ‘resorbable barrier’ that will disappear naturally a few months after it has done its work.
Does bone grafting affect the length of treatment?
If you need bone grafting, it will almost invariably increase the length of time your treatment will take; however, when successfully applied it will greatly improve the outcome of the implant(s) placed. When used in the front of the mouth it can also allow for creation of much better aesthetics.
Bone grafting requires a considerably higher degree of skill from the operator and is often more complex to perform than the placement of the implant itself.
In certain situations some operators will recommend combining the implant placement with bone grafting and the placement of a barrier membrane all at the same time. This considerably reduces treatment time and can produce results that are difficult to achieve any other way. However, many surgeons will still prefer to carry out bone grafting as a distinct stage, so that the implants are only placed when the bone grafting has been successful.
Whatever method is chosen to improve the bone quantity the time, effort and expense is generally well worthwhile.