When a patient goes for dental implant consultation, a topic that frequently pops up is the issue of bone grafting. What is bone grafting and why is it so important? Our natural teeth are supported by bone. Once teeth are lost, the bone loses its purpose and function. The result is resorption. Anybody who has lost all his teeth will have sunken lips and cheeks. Unfortunately, implants also need good bone in order to stay firmly embedded in our jaws. For individuals who have lost their teeth for a long time, the bone is often not ideal for implant surgery. To solve this problem, dentists use a technique called bone grafting.
How is bone added to one’s jaws? The procedure is a surgical one. The dentist must first separate the gums from the underlying bone and then place a matrix over the exposed bone. This matrix will form a framework for the bone cells to build on. Grafting materials may be divided into the following categories.
1. Autografts are “real bone” taken from a donor site to be transplanted on a receptor site in the same individual. As it is the patient’s own bone, there is no chance of rejection. This sort of bone represents the gold standard for grafting materials. The most obvious disadvantage is that you’re robbing Peter to pay Paul. Instead of just one surgical site, there are now 2 sites. The pain/morbidity is often increased.
2. Allografts are materials derived from another individual of the same species. The donors are people who have pledged their organs before their death to better the lives of other others. Of course, bones from dead people must be thoroughly sterilised before they can be used on living people. After grafting, this sort of material is eventually replaced by the host bone.
3. Xenografts are much more often used used than allografts. These materials are processed from animal bone. Cows and horses are the usual sources. Like allografts, they are thoroughly sterilised. They are very safe and no known case of mad cow disease arising from bone graft has been reported. With time, the grafted animal bone will also be converted to host bone.
4. Synthetic Bone can be made from coral, ceramics or different forms of calcium phosphate. The obvious advantage is the safety from cross infection. Rejection is not a serious concern, but synthetic bone will never be completely resorbed and replaced by host bone. Particles of synthetic bone form a matrix around which the host bone will grow. The grafted area will always contain synthetic bone particles embedded in host bone.