Onlay bone grafting
Sinus lift bone grafting
Bone grafting is indicated when there is inadequate width or height of bone necessary for proper implant support and long term success. Bone grafting is a predictable procedure with proven success. Horizontal deficiencies can be corrected using an onlay graft or split thickness approach. Vertical deficiencies can be augmented using a sinus lift bone augmentation in the posterior maxilla or via distraction osteogenesis in other sites.
Onlay bone grafting
Onlay bone grafting is used to augment horizontal atrophy of bone. Autogenous bone is the material of choice and may be harvested from the ramus or chin region for smaller sites or from the hip when larger amounts of bone are needed. The bone is adapted carefully to the recipient site and fixated with micro-screws. Additional bone particulate is often placed to fill the gaps and spaces and then covered with GTR membranes. A tension-less closure is necessary for proper tissue coverage and healing.
Sinus lift bone graft
Teeth loss in the posterior maxilla often results in pneumatization of the maxillary sinus resulting in inadequate height of bone. Since short implants have high rates of failure, it is best to augment such vertical deficiencies to accommodate longer implants (minimum 13 mm). There are two techniques: lateral window osteotomy or internal osteotomy. The lateral window osteotomy technique is used when there is severe height deficiency, while the internal osteotomy technique is used when only a slight additional height of bone is needed (2-3 mm). The ideal bone composition is a mixture of autogenous and allogenic/xenogeneic particulate bones. The procedure is very technique-sensitive and requires keeping the sinus membrane completely intact for proper healing.
The bone grafting materials include autogenous bone harvested from the patient, bovine derivative bone (xenogeneic bone), demineralized, freeze dried bone (allogeneic), and synthetic bone, along with either resorbable or non-resorbable membranes. Growth factors such as platelet rich growth factors or recombinant human bone morphogenic protein materials (rhbmp) may also be used in certain grafting procedures. Bone grafting materials are safe and non-pathogenic. Autogenous bone maybe harvested from ramus or chin if sites are relatively small, or from the hip if larger amounts of bone are needed.
Onlay bone graft requires four to six months of healing timebefore implants can be placed. If the graft is 100% autogenous cortico-cancellous bone, then four months may be adequate. Sinus lift bone grafting requires minimum of six months of healing, although in some instances, eight months may be indicated.
Pain: The level and duration of pain depend on the complexity of the surgery, the technique, and the patient’s tolerance. Most patients experience three to four days of elevated pain, commonly managed with pain medications such as Vicodin or Percocet. As pain gradually diminishes over the next two to three days, Ibuprofen (Advil) or Acetaminophen (Tylenol) can be used. After seven to ten days, most patients no longer have pain and may stop their medications.
Swelling: Any swelling related to surgery will maximize in 36 to 48 hours following the procedure, and gradually taper over the next five to seven days. Ice helps to reduce swelling in the first 24 hours. If extractions were done in a conservative fashion, a patient may experience no swelling at all.
Diet: Upon arrival home, patients may have water, juices, soups, shakes, purees, and very soft food. A soft diet is recommended for up to five to seven days. No hard, crispy, or spicy foods should be eaten during this period. The general rule is, if you have to chew, it’s probably too hard. After seven days, patients may gradually return to normal food.
Activity: Patients should get plenty of rest on the day of surgery. Some patients may feel well enough the following day to walk and go out. That’s alright, but they should take it easy and avoid strenuous activities for the first two to three days. Patients should refrain from sports, lifting, or doing anything that requires exertion. After three days, if patients feel more comfortable, they can walk, go for a gentle swim, or do very low-impact exercise, such as swimming or walking. Mild activities may cause some pain but not enough to disturb the surgery site or open the sutures.
Following a bone augmentation procedure, the transitional prosthesis must be adjusted to prevent tissue pressure. A very light contact or no contact at all is acceptable. But it is preferable to avoid use in the first 72 hours and perhaps the first week after surgery. The patient should be instructed to avoid function on the transitional prosthesis as it may cause occlusal pressure on the tissue and disrupt healing. The prosthesis may be used more freely after two weeks.