Bone grafting is generally done for four reasons:
- One is to create enough bone to place dental implants in advance of implant placement or done at the same time an implant is placed. Dental implants require enough bone around them to support the implant and the associated soft tissue.
- Second is to fill out bone deficiencies usually caused by missing teeth or periodontal disease. In this circumstance bone may be added to fill out a depression where a tooth has been missing. This will create a much nicer contour to allow the implant tooth replacement to look more natural.
- In cases of periodontal disease where bone loss is in between the roots of the teeth or a hole adjacent to a tooth. Bone may be added when attempting to keep and maintain a tooth.
- Peri implantitis is an infection around an implant that usually results from poor hygiene. Bone may be added to treat the area with the hope of rebuilding the lost bone. There are generally four parameters for treatment: (1) If the bone loss around the implant is in the shape of a trough where bone can be added. It is called a walled defect and is the most amenable to treatment. (2) If is if there is an adequate amount of implant still in the bone to maintain the implant function. (3) Is the implant cleanable? (4) Is the patient willing to improve their hygiene? If any of the three parameters for treatment cannot be met then bone grafting may not be the most effective way to resolve the peri implantitis.
Bone grafting can be done in every area of the mouth. The predictability and quantity of the bone is highly dependent upon the area of the mouth and the size and type of graft needed. Access is made through the gum tissue. In the case of bone grafting of the sinus an additional opening is made through the bone under the gum tissue to enter the sinus.
The bone used for grafting is either your own bone (autogenous) , donor bone (allograft) or synthetic bone substitutes (alloplasts). Bone comes in the form of granules, paste, putty or as a block of bone. Each has its place and one or a combination of these products are added to the deficient bone area. The area is closed using an artificial collagen or donor membrane. Many times PRF ( Platelet Rich Fibrin) is used in conjunction with the bone graft. PRF comes from your blood and can contribute to healing of the bone and soft tissue.
Many times the dental implant can be placed at the same time the bone grafting is done. Healing time before the implant can be used for a tooth is 4 months. In the case where the all on four procedure is done the implants may be healed enough by 3 months. If the area to be grafted is large then the bone graft must be placed first an allowed to heal 6-9 months before the dental implant can be placed.
Autogenous material for bone grafting is the gold standard. What makes it difficult to use is that each bone harvesting site requires additional surgery and increased morbidity. The majority of bone grafting today involves a combination of both allografts and alloplasts. The advantage is that we have an unlimited quantity of bone that is available to use.
Although there has never been a documented case of any disease transmission from the millions of donor products be it bone or membrane, the patient must be aware that these are human products and have inherent risks.