Why Are Bone Grafts Sometimes Necessary For Implants?
Whenever a tooth is lost, the underlying bone (in the alveolar ridge) no longer receives the day by day pressures that stimulate natural bone growth that the tooth once exerted on it. Over time, the result is that the bone is "resorbed" in part, at least, back into the body.
The alveolar ridge below the missing tooth may revert all the way back to the lower, "basal bone", level. The process may take a year or several years before you lack sufficient bone to support a dental implant, or even a denture, but the exact speed of bone resorption varies from person to person.
Thus, some patients will need bone graft surgery, plus sufficient time for the grafted-in bone to heal and for surrounding bone tissue to grow, before they can begin the dental implant surgery itself.
But dental bone graft surgeries are not all of the same type. Here is a brief overview of the three major types of bone grafts periodontists perform:
1. Socket Grafts
A socket graft is ideally performed right after a tooth is extracted in order to preserve the alveolar ridge and prevent extensive bone deterioration. Bone material is implanted into the empty socket left by the missing tooth.
In most cases, modern day socket grafts use "xenograft materials". A xenograft is bone from an other than human source such as an animal (usually a cow) that fills the socket and fools the body into thinking it is human bone material. Over time, the body adjusts the composition of this foreign bone material until it becomes human bone.
Plus, the presence of bone in the socket will stimulate the body to fill in the surrounding area with newly produced bone material. Xenografts have been used safely for many years and are very low risk. It typically takes 3 to 6 months for the graft to complete before an implant can be placed.
2. Block Bone Grafts
A second common type of dental bone graft is the block bone graft. This method usually uses human bone (in the form of a small "block") taken from the patient's chin or lower jaw near where the wisdom teeth once were (if you've already had your wisdom teeth removed, that is).
Block bone grafts are often performed where a xenograft would not provide enough bone bulk to build up the deteriorated ridge. Otherwise, it works about the same way as a socket graft.
3. Sinus Lift Grafts
Finally, there are times when the maxillary sinus cavity gets too close to parts of the upper jawbone where a dental implant needs to go.
If there is less than 5 mm of space between bone and sinus, your periodontist will need to gently lift back the sinus membrane and place a bone graft to create sufficient space. It can take 6 to 9 months after a sinus lift graft before implants can be placed.
To learn more about bone grafts and dental implants, contact periodontist Dr. Raymond A. Kenzik in Ormond Beach, FL, for a free initial consultation.