Over a period of time, wherever a tooth is missing the surrounding bone will be reabsorbed. This often leaves a condition in which there is poor quality and quantity of bone suitable for placement of dental implants. In these situations, most patients are not candidates for placement of dental implants unless the area is built up with bone grafting.
Today, we have the ability to grow bone where needed. This gives us the opportunity to place implants of proper length and width to restore functionality and aesthetic appearance.
Minor Bone Grafting
The most common type of bone graft performed in our practice is the immediate Bone graft for socket preservation (IBGSP).
The IBGSP is done on the day of tooth extraction and the patient needs to begin pre-operative antibiotics two days before surgery. Seizing this opportunity to preserve the width of the bone housing for future implant placement is also the most cost effective approach.
When a tooth is deemed non-restorable and a patient knows that they want to replace it with an implant they need to have the tooth removed by the Oral and Maxillofacial Surgeon that will later be the one placing the implant. Why? Well, there are two main reasons. Firstly, we know that the bone on the cheek side of the tooth is very thin and often nonexistent so, the site collapses in on the day if the extraction. Secondly, when there is chronic infection, the bone is destroyed in a process called, osteolysis and again the site collapses in.
Another procedure done in our office is the autogenous onlay black graft. Autogenous simply means the patient’s own bone. Onlay block Bone grafting can repair jaw defects sites with inadequate bone structure due to previous extractions without IBGSP. The bone is your own bone taken from the lower posterior jaw. These blocks of bone graft are screwed with lag screws.
Sinus bone grafts are also performed to replace bone in the posterior upper jaw. In addition, a resorbable (melt away) collagen membrane may be utilized to protect the bone graft and encourage bone regeneration. This is called guided bone regeneration or guided tissue regeneration.
Major Bone Grafting
Major bone grafts are typically performed to repair larger defects of the jaws. These defects may arise as a result of traumatic injuries, tumor surgery, or congenital defects. Large defects are typically repaired using the patient's own bone. This bone is harvested from a number of different sites depending on the size of the defect. The skull (cranium), hip (iliac crest), or tibia (the area below the knee and above the skin), are common donor sites. These procedures are routinely performed in an operating room and may require a hospital stay.
Sinus Lift Procedure
The maxillary sinuses are behind your cheeks and on top of the upper molar teeth. Sinuses are like empty rooms that have nothing in them. Some of the roots of the natural upper teeth extend up into the maxillary sinuses. When these upper teeth are removed, there is often just a thin partition of bone separating the maxillary sinus and the mouth. Dental implants need bone to hold them in place. When the sinus floor is very thin, it is impossible to place dental implants in this bone.
There is a solution and it's called a sinus floor graft or sinus lift. The sinus membrane is then lifted upward and donor bone is inserted into the floor of the sinus. Keep in mind that the floor of the sinus is the roof of the upper jaw. After several months of healing, the bone becomes part of the patient's jaw and dental implants can be inserted and stabilized in this new thicker bone.
The sinus graft makes it possible for many patients to have dental implants when years ago there was no other option other than wearing dentures.
If enough bone between the upper jaw ridge and the bottom of the sinus is available to stabilize the implant initially then, sinus augmentations and implant placement can sometimes be performed as a single procedure. If not enough bone is available, the sinus augmentation will have to be performed first, then the graft will have to mature for several months. Once the graft has matured, the implants can be placed.
In some cases, the bony ridge will appear to be the normal height on a regular dental X-Ray (2D) but, the 3D x-ray reveals a very narrow or “knife edge” ridge form. The previously described bone graft procedures are placed to increase ridge height and/or width. This technique is used to restore the bone width dimension when the jaw ridge gets too thin to place conventional implants. In this procedure, the bony ridge of the jaw is literally expanded using a piezo electric (“wet saw”) ridge splitting technique and a series of intraposed screws, wedges, or rarely implants combined with interposed bone grafting (sandwich graft). This bone graft is allowed to mature for a few months before placing the implant.