For those of you having to undergo implant surgery, you've probably been advised that you might require a bone graft. What is a bone graft and why is it necessary? A bone graft is the addition of bone to your own bone so as to increase the bone material around your future implant. An implant requires approximately 2mm of bone thickness around its structure embedding it in a solid foundation for long-term use and success.

Types of bone grafting material:

• Autograft: This human bone is the patients' own bone. The bone is removed from a donor site and transferred to the recipient site. Common donor sites include the upper and lower corners of the mouth where the wisdom teeth are usually present as well the chin area. This type of bone is the gold standard of bone grafts.
• Allograft: This is also human bone but bought through an overseas bone bank.
• Xenograft: This bone is not human but either pig or cow bone. This bone is completely rid of all its organic content only to leave its inorganic mineral content. These bone substitutes have been used for many years and carry very high success rates with minimal repercussions.
• Synthetic variants: bone replacement materials include bone ceramics like hydroxyapatite and tricalcium phosphate.

The Concept

Bone grafting is possible because bone tissue, unlike most other tissues, has the ability to regenerate completely if provided the space into which to grow. As native bone grows, it will generally replace the graft material completely, resulting in a fully integrated region of new bone. 

Causes of bone loss

1. Trauma
2. Periodontal Disease
3. Long-term tooth loss
4. Genetically Missing teeth

When is bone grafting necessary?

• Anterior implants: It is crucial that the aesthetic zone is looking perfect. Gum tissue is supported by bone. If the bone is missing the gum tissue, including the interdental papillae may look collapsed or insufficient giving rise to a shadow or an asymmetric unaesthetic feature. Missing anterior teeth, usually due to trauma more often than not require bone grafts.
• Posterior implants: In the upper jaw the loss of posterior teeth reduces the volume of bone present between the gums and the sinuses above them. If not enough bone is present then the floor of the sinus must be raised and a bone graft placed below it. This is crucial for the long-term success rate of the implant. In the lower jaw missing bone reduces the distance between the gum and the inferior alveolar nerve running through the jaw. To increase the distance between the nerve and the gum, blocks of bone must be placed below the gum.

In most cases, implants may be inserted at the same time as the bone graft. However, in some cases the bone must first be grafted and then the implants inserted a few months later. Yes, placing bone grafts is not the most pleasant of procedures but it does mean that you can have dental implants, which will make eating once again a pleasure. Explore your options, see what's best for you and ask your dentist for advice!