Bone density indirectly indicates an individual’s risk of fracture. Bone density is determined by performing an investigative test to measure the degree of mineralization of trabecular bone that is present in a certain volume of bone. The degree of mineralization can be determined using dual-energy X-ray absorptiometry (densitometry). Dental Implant Surgeons use the quantitative measurement of minerals in bone to indicate the structural strength of a patient’s jawbone.
Historically, the volume of a patient’s exiting bone was the main factor used when creating a dental implant treatment plan. When less bone was available, fewer and/or shorter implants were used. Patients with large bone volumes would receive more and/or longer implants. However, treatment plans today take the final prosthesis options into consideration first. The patient’s desires are noted. Bone density in the areas where implant abutments will be placed must be evaluated.
Today, it is the density of the bone that determines treatment planning, including:
- Surgical approach
- Implant design
- Healing time
- Initial progressive bone loading during prosthetic reconstruction
What is atrophy? Bone atrophy, also known as osteonecrosis of the jaw, occurs when the underlying jawbone begins to deteriorate. This can occur for a number of reasons. Some bone atrophy causes include but are not limited to bacteria due to periodontitis or teeth that have been removed but not replaced, usually in the case of more than one tooth. In the latter case, bone loss occurs when the pressure of chewing no longer stimulates and preserves the jawbone. Osteoporosis bone atrophy can also be an issue in older patients, where the disease causes system-wide bone loss that includes the jawbone.
Bone atrophy symptoms can include pain or discomfort in the area of the deterioration, as well as a “sinking” appearance when the bone loss is severe. However, not all patients will have symptoms and osteonecrosis may only be revealed through imaging and other diagnostic testing. A significant indicator of the potential presence of bone atrophy is advanced gum disease.
Bone augmentation for dental implants are sometimes necessary when a patient does not have enough bone available to properly anchor the screw or other implant hardware. Dental bone augmentation includes a variety of procedures, including sinus lifts, bone graft procedures, and manipulation of bone using an osteotome or osteotome mallet. Since an implant cannot be done without a certain amount of bone available, it becomes necessary for a periodontal surgeon to stimulate the patient to grow more bone in the area, or to remove bone from one area and place it in the area where the implant will be done.
Bone augmentation procedures in implant dentistry are not uncommon, especially in cases of bone atrophy, where tooth loss without replacement has caused the deterioration of bone over time. Bone augmentation surgery can be done to improve the likelihood of being able to place an implant, but it does require implant surgery to be delayed while the bone heals.
If a patient has been missing his or her natural teeth for some time, a substantial amount of bone resorption is likely. This lack of bone makes placing endosseous dental implants a challenge. Typically, bone-grafting techniques have been used to address this problem; however, bone-grafting techniques require two surgical procedures, are time consuming and costly for the patient. Although bone-grafts are still available and widely used, a bone condenser can eliminate the need for a bone-grafting procedure before implant placement.
Instead of using a bone-grafting technique to address narrow ridges, an osteotome can be used to condense and expand the alveolar bone. The osteotome is designed to cut and/or prepare bone. This surgical instrument is similar to a chisel; however, it is beveled on both sides. This repositioning and remodeling of the alveolar bone allows the surgeon to securely screw the implant into the jaw joint. The bone condenser is also the tool used while performing an internal sinus lift.
When not enough bone is present for a dental implant, bone condensing may be necessary. This is achieved through what is known as an osteotome or an osteotome mallet. What is an osteotome? It’s a surgical instrument that can be used in multiple ways to manipulate the bone to better suit a dental implant.
During an osteotomes dental implant, a surgeon will utilize an osteotome mallet — one of several wedge-shaped instruments that have different size tapers — to cut, compress, or deform the bone to help facilitate implantation of screws or other hardware. An osteotome sinus lift can be used to help patients regenerate their own bone tissue before an implant. This procedure is generally considered safe and produces predictable results, where the atrophic maxilla generates more bone volume that will better anchor an implant in the future.
When bone condensing and other osteotome procedures are needed, implant placement is typically delayed until enough bone volume is achieved to stabilize an implant.
Once a natural tooth is no longer anchored within the jawbone, deterioration begins. This deterioration affects the vertical and horizontal aspects of the bone. The term used when referring to this type of bone loss is ‘resorption.’ Resorption occurs when the tooth is gone and the jawbone is no longer stimulated. Individuals with a substantial amount of jawbone resorption who want endosseous root-formed implants placed will need to have a bone-grafting or osteotome technique performed first.
Endosseous root-form implants offer an excellent, long-term success rate; however, if these implants are placed in bone of deficient quality and volume, the implant survival rate falls. With a narrow bone ridge, endosseous root-form implants cannot be placed and expected to provide the patient with a long-term dental solution. Although bone-grafting is always an option, the osteotome technique offers patients a faster, less taxing solution to resorption issues. Surgeons use the osteotome technique to expand and reposition the alveolar bone to create a strong foundation for dental implant placement.
Bone conduction, or osteoconduction, is a bone matrix that provides bones with the materials they need to remain strong. Living bone cells are responsible for making and maintaining this matrix. The bone cells within the matrix assist with bone rejuvenation and the healing process. Bone grafts are used to promote healing and growth. A successful bone graft is dependent upon several principles, including osteoconduction, osteoinduction and osteogenesis. Osteoconduction provides the guidance, osteoinduction encourages the transformation of undifferentiated cells to active bone cells and osteogenesis, living osteoblasts within the graft material aid in the bone renovation process.
Osteoconduction guides the reparative growth of the native bone. The material used for the bone graft serves as the framework for the new bone growth that is propagated by the patient’s natural bone. Osteoblasts from the defected area that is being grafted utilize the grafting material as a scaffold. The osteoblasts use this framework to spread and create new bone. Guiding new bone growth requires the use of bone-graft material that is osteoconductive.
Bones consist of a bone matrix: It is this matrix that gives bones their strength. Living bone cells make and maintain the matrix. The cells within this matrix are responsible for helping with the rebuilding and healing of bone.
A bone biopsy may be performed by an implant surgeon to determine the health of the jawbone. To ensure the patient remains comfortable throughout the procedure, local anesthesia is provided. Samples may be taken from numerous areas for comparison purposes. Most likely, the bone curette will be used to collect these samples.
A bone curette is a surgical instrument that has a tiny spoon at the end (it looks similar to an ice-cream scoop). The bone curette’s edges are sharp and the handle may be bulbous or small and thin. The size of the scooper varies, and different angles are also available. This instrument is specially designed to scrape bone.
The material that gives bones such strength is referred to as the bone matrix. This matrix consists of living bone cells. These cells assist with the repairing and healing process of bone. Bone curettage refers to the removal of bone through that act of scraping it with a curette.
When the bone is surgically shaved or smoothed during a bone curettage procedure, the bone matrix is activated and begins the regeneration process. This process is beneficial because it helps heal the bone surrounding the implant; thus, encouraging the start of the osseointegration process.
The curette that is used to shave bone resembles a small ice-cream scooper. This surgical instrument has sharp, durable edges. The handle of the bone curette may be bulbous, easily filling the entire hand, or it may resemble one of the thin, silver explorer instruments frequently used by a dentist. Various curette sizes, designs and curvatures are available.
The material responsible for giving bone its hard surface and strength is the bone matrix. This matrix is full of living bone cells. These cells make and maintain the matrix to help with bone rejuvenation and healing. By smoothing the bone, the matrix is activated and begins the healing process.
This instrument is used to carefully smooth bone. With a small spoon on the end of the tool similar to that of an ice-cream scoop, a curette allows the surgeon to scrape away bone. The spoon of the bone curette has durable, sharp edges. Its handle may be large and thick, taking up the entire hand, or small and thin. In addition, scooper sizes vary. These instruments can also be angled forward, backward or just remain straight.
The bone curette may be used to collect a bone sample for a biopsy, to determine the health of the bone in certain areas of the jaw or to prepare the bone for dental implant placement.