Implants need healthy bone and gum tissue for support. In some cases, the bone and gum tissue is deficient. In these cases, the implant sites can be improved with bone and soft tissue grafting or augmentation.
For dental implants to be successful, the jawbone must have enough bone to support them. You may not have enough bone because of tooth loss from periodontal (gum) disease, injury or trauma, or a developmental defect. If your jaw is too short (up and down), too narrow (side to side), or both, you will need a procedure to add bone to your jaw before implants can be placed.
Bone grafting or augmentation is a term that is used to describe a variety of procedures that are used to "build" bone so that dental implants can be placed. These procedures typically involve adding bone or bonelike materials to the jaw, and waiting for the grafted material to fuse with the existing bone over several months.
There are several different procedures and sources of bone that can be used for bone augmentation. Your oral surgeon will select a procedure depending on the type, location and number of implants to be used. If you need a bone graft, it is important that you and your oral surgeon discuss all of the options available to you.
Ridge-augmentation with Onlay GraftingOnlay Grafting is typically reserved for cases where bone support is very deficient. A bone graft using your own bone is placed to increase the ridge width and/or height. In these situations, the graft is taken from another area inside your mouth and transplanted into the deficient area. Once transplanted, it will grow in its new location. This in-office procedure is usually performed using a sedative or general anesthesia.
Guided Tissue Regeneration (GTR) a.k.a. Guided Bone Regeneration (GBR)
GTR can be used is cases where the bone support mildly to moderately deficient. Your own bone can be used; however GTR is most often done using particulate bone substitutes. Using bone substitutes gives the advantage of not needing an additional procedure to take your own bone. There are several types and sources of bone substitutes. Your oral surgeon will discuss the most appropriate one with you.
The deficient area is filled with bone or a bone substitute and covered with a protective membrane. Early on, the filler material will support the tissue surrounding the deficient area, and in time will be replaced by new bone.
A sinus lift, sometimes called a sinus augmentation, is surgery that adds bone to your upper jaw in the area of your molars and premolars to make it taller. The bone is added between your jaw and the maxillary sinuses, which are on either side of your nose. To make room for the bone, the sinus membrane has to be moved upward, or "lifted." A sinus lift is done when there is not enough bone in the upper jaw, or the sinuses are too close to the jaw, for dental implants to be placed.
Ridge Expansion and Ridge Spreading
A ridge expansion of spreading is a type of bone procedure that can be done when the jaw is not wide enough to support implants. Your surgeon uses special instruments to split or spread the area of jaw bone that supports the implant.
One of the newest procedures for augmenting areas of bone is called distraction osteogenesis. This procedure originally was used for lengthening the bones of patients with abnormally short legs. It now has been adapted for use in the mouth. A surgeon makes cuts in your jawbone to separate a piece of bone from the rest of the jaw. A titanium device inserted into the jaw with pins or screws holds the piece of bone apart from the rest of the jawbone. Over time, the space between the piece of bone and the jawbone is widened slightly by unscrewing the device, and the area between the pieces gradually fills in with bone. "Distraction" refers to the process of separating the two pieces of bone, and "osteogenesis" refers to the forming of new bone. Distraction osteogenesis is used more often to make the jawbone taller, but it can be used to increase the bone in any direction. The procedure is becoming more common.
Soft Tissue Grafting
When soft tissue support is deficient a Connective Tissue Graft may be performed A small piece of tissue is taken from your palate and placed to cover the defect.