A bone graft can be obtained from the patient, a donor, an animal or be entirely man-made. The type of graft used is determined by your surgeon within varying circumstances.
Bone Grafts for Dental Implants
Bone grafting within the fields of dentistry is essential to complete many procedures. The majority of oral surgical offices have successfully used bovine bone (cow bone) as a standard graft material for many years. The technique behind the success of this form of grafting is due to the bovine bone graft being used as a mechanical stabilizer within the body, which means it prevents the surrounding bone or soft tissues from collapsing. A chemical process used to regrow tissue fools the body into accepting the bovine graft as the native bone and over time dissolves and replaces it.
Simpler Bone Grafting Procedures
While major autogenous bone grafts are periodically needed to house dental implants, they have been greatly replaced by three simpler outpatient bone grafting procedures that involve one or a combination of graft methods:
- The“Socket Graft”
- The “Block Bone Graft”
- The “Sinus Lift Procedure”
The dentist will likely offer some form of grafting options when a patient considers the placement of dental implants to accompany this process. He or she will discuss which of these procedures is the best one for you and why. The dentist can also answer questions regarding the perioperative experience and the convalescence period after the operation. These three outpatient graft procedures are performed without causing discomfort to the patient in a relaxing environment with either local anesthesia or sedation via an IV. Therefore, it behooves the patient to have the dental surgeon explain what each of these grafts are used for and how they are typically achieved.
The “Socket” Graft
There are instances when the application of implants can be done immediately after an extraction. When a dental infection or space discrepancy doesn’t allow for an immediate implant replacement, an alveolar ridge preservation graft (socket gap) is used to fill the gap created by a tooth extraction to maintain its space while the native bone has the time to grow and bridge the gap with live bone. A simple tooth extraction will create a hole that is surrounded by a tooth supporting bone or alveolar bone. In reaction to the freshly pulled tooth, the body rapidly begins to resorb or dissolve this bone unless it is immediately filled with another tooth or an implant.
The graft material used most often for the “socket graft” is composed of sterile, freeze-dried bovine bone (healthy cow bone). The graft is immediately applied to the cavity after a tooth extraction and is secured using a pledget of collagen and one or two biodegradable sutures.
The “Block Bone Graft”
It is sometimes necessary to harvest the patient’s own bone to assist in a bone grafting if the bovine bone ( sometimes another composite material is used) can’t adequately replace or provide enough bulk to the amount of bone missing after an extraction. The block bone graft is obtained from the region (mandibular ramus) where the third molars (wisdom teeth) were located. An alternate site used to obtain a block of bone is the chin. Various dental scenarios would require the application of a block bone graft such as when:
- There is extensive bone destruction or bone loss from trauma.
- Areas where teeth were extracted without immediate placement of an implant, socket graft, or tooth-re-implantation.
The supporting bone of the tooth never developed.
The block graft is then fastened with one or two tiny screws and coated with particulate bovine bone and a collagen membrane. The surgical site is securely closed and given four months to fuse to the underlying jawbone before an implant is placed. The mature bone graft supports the soft tissue structure and houses the implant in “living” bone in a hygienic, aesthetic manner that can be easily maintained.
The Subantral Graft or “Sinus Lift Procedure”
The “sinus lift procedure” is a simple solution to allow implants to substitute for maxillary molars. Some less experienced periodontists and restorative dentists may be a little intimidated performing this operation to the extent it is needed; however, it is a regularly performed procedure for the oral and maxillofacial surgeon which won’t produce chronic sinus pain or an adverse effect on the patient’s sinuses.
The subantral grafting procedure is performed by creating a small incision in the sinus above the maxillary teeth’s roots. Implant placement can be done as an “immediate” or “delayed” restoration following a subantral graft which is determined by the volume of native bone present between the sinus and the oral cavity.