Replacing Bone for Dental Implants
The destructive gum disease known as periodontitis can lead to the loss of natural teeth and of bone. Without effective treatment and maintenance, the same periodontal bacteria that infects the gum tissue will continue to invade the underlying tissues, slowly eating away at the ligaments and alveolar bone that hold the teeth in the jaw. Loss of teeth, in and of itself and independent of bacteria, also contributes to bone loss, as the bone is supported and stimulated from the pressures of chewing and the strength of the roots of the teeth; when the root support and chewing function are removed, the bone is slowly resorbed into the body. It is estimated that about 25% of the bone is lost in the first year after a tooth is extracted or falls out, and the bone continues to resorb in the absence of stimulus and root support. When the upper molars are removed, this can lead to additional bone resorption that migrates into the sinuses.
If you are seeking treatment that includes the placement of dental implants and implant-supported or implant-retained dentures, your dentist may recommend a bone graft before these implants can be placed. Bone grafts help the body produce new, healthy alveolar bone that replaces lost bone and provides a solid, stable, and healthy foundation for dental implants and the restorations they support. Bone grafts may also be used to support natural teeth that are affected by periodontitis but have not fallen out or been extracted; the stability provided by bone grafts can, in some cases, help retain healthy teeth and prevent them from falling out or needing to be removed. If a bone graft is necessary, a periodontist will perform the surgical grafting procedure. First, the periodontist will move an area of the gum tissue, folding it back to expose the area beneath the gums. Then, the periodontist thoroughly cleans the exposed area, removing any infected tissue, bacteria, and tartar, and smoothing out rough surfaces that can exacerbate gum disease by encouraging the accumulation of additional bacteria and plaque. Once the area is thoroughly cleaned, the bone graft material is placed in the treated area. The type of bone graft will depend on the specific clinical needs of the patient.
While bone grafts can help patients retain their natural teeth, they can also be used to provide a stable support system for dental implants and implant-based dental restorations. Dental implants are small cylinders that are surgically implanted into the jaw and can be used to support one or more missing teeth; the replacement teeth, or crowns, are affixed to the top of the implants once they have healed into the jaw. Because dental implants function much like a tooth’s root would, supporting the dental restoration and providing a foundation for biting and chewing, the bone that surrounds the implant must be strong and stable. When there isn’t sufficient bone present to safely and stably place a dental implant, a bone graft may be necessary. Once the bone graft has fully healed and new, healthy bone has begun to replace the grafting material, the dental implant can be safely placed; on occasion, when only smaller grafts are needed, the graft may be able to be placed during the same procedure as the dental implant.
There are a few different types of bone grafts, and the type of graft selected by your periodontist will vary depending on your specific needs and their preferences. An autograft is a bone graft that uses the patient’s own bone, usually extracted from the hip bone or the back. An allograft is a bone graft that uses bone that has been sourced from a human donor. A xenograft is a bone graft that uses bone that has been sourced from an animal; bovine bone is the most common choice for xenografts. An alloplast is a bone graft that uses a synthetic material that is chemically similar to bone, containing calcium and phosphorus in addition to other materials. Different materials and procedures serve different purposes and meet different preferences, and your dentist can work with you to determine which procedure and material are best suited to your clinical needs.
In addition to bone graft procedures, periodontists may use additional methods to encourage a patient’s body to regenerate healthy bone and other tissues when the alveolar bone of the jaw has been compromised. Mesh membranes or growth factor proteins are two of the supplemental treatment options that can enhance the body’s ability to regrow healthy bone. Mesh membranes are used in a treatment process called guided tissue regeneration. In guided tissue regeneration, the dentist inserts a very small piece of mesh in the area between the bone and the gum tissue. This mesh serves as a sort of a dam, preventing the gum tissue from growing into the area where new bone is intended to grow. Clinical techniques like guided tissue regeneration are constantly being explored, and new enhancement to treatment procedures are consistently developed. These innovations include new varieties of bone graft materials, different types of barrier membranes for use in guided tissue regeneration, multiple types of growth factors, and combinations of all of these methods used in conjunction, and scientists are continually developing new techniques and materials and improving on those that are already in use.
Of course, the best way to avoid bone loss related to periodontitis is to prevent gum disease from occurring in the first place. Regular, effective oral hygiene is an important part of disease prevention. Dentists recommend gently brushing the teeth twice daily with a soft-bristled brush and fluoride toothpaste, in addition to cleaning between the teeth once a day. It is also important to see your dentist regularly for periodic checkups and professional cleanings. Gum disease is often symptom-free in its earlier stages, but it is in these earlier stages that it is also reversible, which makes early detection through professional checkups an integral part of prevention. Even when gum disease has progressed beyond its earlier stages, periodic professional cleanings can slow the development of periodontitis and prevent the destruction it gradually wreaks on the teeth, gums, bone, and other tissues in the mouth. Dentists may also recommend changes in diet or the cessation of detrimental habits for people with periodontitis, and with regular care and behavior modification, patients may be able to preserve the health and function of the mouth for a sustained period of time. While the effects periodontitis cannot be reversed, it can be slowed or stopped with the proper care.