Grafting Procedures for Dental Implants
Socket Preservation-Preserving Your Jaw Bone after Extraction
Removal of teeth is sometimes necessary because of pain, infection, bone loss or fracture of the tooth. The bone that holds the tooth in place (the socket) is often damaged by disease and/or infection resulting in deformity of the jaw after the tooth is extracted. In addition, when teeth are extracted, the surrounding bone and gums can shrink and recede very quickly after the extraction resulting in unsightly defects and collapse of the lips, and cheeks.
These jaw defects can create major problems in performing restorative dentistry whether your treatment involves dental implants, bridges or dentures. Jaw deformities from tooth removal can be prevented and repaired by a procedure called socket preservation. Socket preservation can greatly improve your smile’s appearance and increase your chances for successful dental implants for years to come.
Several techniques can be used to preserve the bone and minimize bone loss after an extraction. In one common method, the tooth is removed and the socket is filled with bone or bone substitute. It is then covered with gum, artificial membrane, or tissue-stimulating proteins to encourage your body’s natural ability to repair the socket. With this method, the socket heals eliminating shrinkage and collapse of surrounding gum and facial tissues. The newly formed bone in the socket also provides a foundation for an implant to replace the tooth. If your dentist has recommended tooth removal, be sure to ask if socket preservation is necessary. This is particularly important if you are planning on replacing the front teeth.
What is Bone Grafting?
Over a period of time, the jawbone associated with missing teeth atrophies (shrinks) and is reabsorbed. This often leaves a condition in which there are 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.
With bone grafting, we now have the opportunity to not only replace bone where it is missing but also the ability to promote new bone growth in that location! This not only gives us the opportunity to place implants of proper length and width, but it also gives us a chance to restore functionality and esthetic appearance.
Bone grafting can repair implant sites with inadequate bone structure due to previous extractions, gum disease or injuries. There are several bone graft options and Dr. Russo and Dr. Braga will discuss which is suitable in your individual case. Sinus bone grafts are also performed to replace bone in the posterior upper jaw. In addition, special membranes may be utilized that dissolve under the gum and protect the bone graft and encourage bone regeneration. This is called guided bone regeneration or guided tissue regeneration.
Types of Bone Grafts
Autogenous Bone Grafts:
Autogenous bone grafts, also known as autografts, are made from your own bone, taken from somewhere else in the body. The bone is typically harvested from the jaw or chin. Autogenous bone grafts are advantageous in that the graft material is live bone, meaning it contains living cellular elements that enhance bone growth.
However, one downside to the autograft is that it requires a second procedure to harvest bone from elsewhere in the body. Depending on your condition, a second procedure may not be in your best interest.
Allogenic bone, or allograft, is dead bone harvested from a cadaver, then processed using a freeze-dry method to extract the water via a vacuum. Unlike autogenous bone, allogenic bone cannot produce new bone on its own. Rather, it serves as a framework or scaffold over which bone from the surrounding bony walls can grow to fill the defect or void.
Xenogenic bone is derived from a non-living bone of another species, usually a cow. The bone is processed at very high temperatures to avoid the potential for immune rejection and contamination. Like allogenic grafts, xenogenic grafts serve as a framework for bone from the surrounding area to grow and fill the void.
Both allogenic and xenogenic bone grafting are advantageous in that they do not require a second procedure to harvest your own bone, as with autografts. However, because these options lack autograft’s bone-forming properties, bone regeneration may take longer than with autografts, with a less predictable outcome.
Graft composites consist of other bone graft materials and growth factors to achieve the benefits of a variety of substances. Some combinations may include collagen/ceramic composite, which closely resembles the composition of natural bone, DBM combined with bone marrow cells, which aid in the growth of new bone, or a collagen/ceramic/autograft composite.
What is a Sinus?:
The maxillary sinuses are behind your cheeks and on top of the upper teeth. These sinuses are empty, air-filled spaces. 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 wall of bone separating the maxillary sinus and the mouth. Dental Implants need bone to hold them in place. When the sinus wall is very thin, it is impossible to place dental implants in this bone.
The Sinus Augmentation Procedure:
The key to a successful and long-lasting dental implant is the quality and quantity of jawbone to which the implant will be attached. If bone loss has occurred due to injury or periodontal disease, a sinus augmentation can raise the sinus floor and allow for new bone formation.
In the most common sinus augmentation procedure, a small incision is made on the premolar or molar region to expose the jawbone. A small opening is cut into the bone, and the membrane lining the sinus is pushed upward. The underlying space is filled with bone grafting material. After the bone is implanted, the incision closed and the healing process begins. 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 sinus bone.
If enough bone between the upper jaw ridge and the bottom of the sinus is available to stabilize the implant well, 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, depending upon the type of graft material used. Once the graft has matured, the implants can be placed.
The sinus graft makes it possible for many patients to have dental implants when years ago there was no other option besides wearing loose dentures.
Soft tissue grafting
Gum tissues often atrophy or shrink, creating both functional, hygienic and aesthetic dilemmas. The gums can also be damaged during extraction if a dentist is not careful when handling the soft tissues during surgery. Studies have shown a type of tissue called “keratinized gingiva” is essential for implant hygiene and health. Soft tissue grafts can replace missing gum tissues for a better aesthetic outcome as well as to prepare for dental implant placement when needed.
Before & After Photo of Soft Tissue Grafting at Dental Implants. Note black line indicating increased in thick healthy Gum Tissue to support the implants and protect the underlying bone
Before & After Photo of Soft Tissue Grafting at Anterior Dental Implant. Note Coverage of Implant Recession and increase in thick healthy tissue.