Bone and Soft Tissue Augmentation in Implantology

Fig 2-10bFailed augmentation with bovine bone substitute material. Part of the material spontaneously perforated the soft tissue.

Fig 2-10cPartially regenerated bone substitute material but with important infiltration in the soft tissue area.

Fig 2-11aPanoramic radiograph after treatment of a complex midfacial fracture with multiple osteosynthesis in the maxilla and the remains of an important bony defect in the anterior tooth area.

Fig 2-11bFracture-related open bite.

Fig 2-11cWax-up of the desired prosthetic result for the planning of a bone reconstruction with an autogenous graft.

The bone quality of the regenerated area is generally classified as reduced, especially when using biomaterials (xenogenic or allografts). By applying the 3D technique with an intraoral bone transplant, iliac crest reconstruction using monocortical strips, and compressed cancellous bone or distraction osteogenesis, a vital and stable bone bed can be achieved that corresponds to a bone class of D2 or D3. Depending on the bone quality, it is important that dysfunctions are detected early to prevent possible overloading of the implant site due to bruxism.

Determining the bone volume is suitable as an initial and immediately available means to so-called bone mapping. The height of the soft tissue situation is determined with a pointed needle and a rubber stopper. By transferring these measured values to a saw-cut model, the existing bone volume can then be measured ( Fig 2-12aand b). This kind of diagnostic measuring is rarely used today due to the increased use of digital diagnostic methods such as cone beam computed tomography (CBCT). The use of appropriately modified calipers has not proven to be successful in clinical practice and therefore they are only of historical significance today.

In the context of implant therapy, especially in the atrophic jaw, radiologic diagnosis provides the essential information for deciding on the possibilities and scope of the necessary therapy and ensuring the treatment result. Radiologic diagnosis delivers the relevant information for the protection of the anatomical structures in the surgical field. In addition to the purely volumetric assessment of the jaw, the bone structure is also evaluated.

Due to chronic infections, especially after multiple endodontic treatments with revisions of the root fillings, apical root resections or any other infection, sclerotic changes in the jawbone can be seen. As a rule, these are not relevant for further implant therapy because the body’s own immune system has healed the infection through the inflammatory process; in fact, it sometimes repairs more than necessary through new bone apposition. This increases the bone density and the possibility of achieving high primary implant stability. On the other hand, increased bone density makes implant bed preparation more difficult, and in case of insufficient cooling can increase the risk of burning the bone. In rare cases, a more or less pronounced local osteomyelitis may be present.

Osteomyelitis sclerosans Garré is an infectious bacterial chronic event that is sustained by a persistent infection or by itself. Microbiologically, bacterial growth can rarely be detected by an intraoperative swab test. If there is anamnestic evidence of a persistent bony inflammation with symptoms, it is recommended to consider a CBCT ( Fig 2-13) or a skeletal scintigraphy to exclude chronic subacute processes.

For therapeutic planning, all radiologic procedures in dentistry are now applied on an indication-related basis depending on the different forms of implant prosthetic therapy, from single tooth replacement after traumatic tooth loss to maxillary ridge reconstruction in severely atrophied jaws.

The use of periapical radiographs is particularly recommended to obtain clearer detail of the teeth, bone, and implants. This kind of diagnostic technique is especially recommended for the determination of bone loss around implants or teeth and for the detection of caries ( Fig 2-14aand b). In case of planning a bone augmentation, especially if using vertical bone augmentation techniques, periapical radiographs are recommended to detect bone structures covering the neighboring teeth. This information is very important, since vertical bone grafting is limited to the bone level of the neighboring teeth.

Fig 2-12aMeasurement of mucosal thickness with a thin needle with an attached endo stopper.

Fig 2-12bTransmission of mucosal thickness measurement on a saw-cut model.

Fig 2-13Important sclerosis close to the basal areas of the edentulous part of the mandible after failure and removal of all implants inserted in grafted bone from the iliac crest. The patient’s history reveals the extraction of several teeth after multiple apicoectomies due to long-term chronic infections.

Fig 2-14aPanoramic radiograph documenting an implant at the area of the central left incisor and some apical reactions on the second premolar and first maxillary left molar. A peri-implant pathology is difficult to detect here.

Fig 2-14bPeriapical radiograph documenting a severe peri-implant bone loss and a deep caries on the neighboring lateral incisor. A thin bone layer is still covering the neighboring roots.

Fig 2-14cDetermination of the vertical bone dimension with reference balls.