As individuals, we all resorb at different rates and some patients may suffer severe bone atrophy leaving a flat ridge that is unable to retain a denture without it floating. Then, the maxillary sinus enlarges as we age and this may create a paper thin bone in the upper jaw. Osseous (bone) grafting can be used to raise the floor of the sinus and create adequate support to place root form implants. In the lower jaw as the bone resorbs, the inferior alveolar nerve (a large nerve running through the mandible) may interfere with implant placement. To circumvent this problem, the inferior alveolar nerve can be repositioned to allow implant placement.
Implants are constructed of titanium or titanium alloy. Extensive studies have demonstrated that titanium is completely biocompatible, causes no allergic reactions and is completely accepted by the body. During the fabrication of the implant, an oxide layer forms on the titanium surface upon which the bone will fuse (Osseointegrate). Additionally, the surface of the titanium can be treated with hydroxyappatite or sprayed with titanium (TPS) to improve the osseointegration.
Dental implants are divided in two categories based on whether they are placed within the bone (Endosseous) or on top of the bone (Subperiosteal).
Endosseous implants are placed within the bone and are subdivided into two groups, root form and blade form. These types of implants are placed to secure either single crowns, fixed bridges or to retain removable prosthesis (dentures).
Blade form implants, also known as plate form, are flatter in appearance and are utilized when there is insufficient width of bone but adequate depth is present. They are available in various shapes to fit in and around anatomical structures such as the maxillary sinus and inferior alveolar nerve. Blade implants have been used to treat edentulous jaws since 1960.