At the beginning of implantology, doctors were faced with such a deficit of bone tissue as a very narrow alveolar process. At that time, the only way to increase its width was to split it like a “green twig”. In this case, a deep furrow was made longitudinally in the process, an instrument was inserted into it, and the outer plate was broken, the resulting space was filled with bone material. But this method did not guarantee the creation of an acceptable contour. Research conducted over the past decade on bone physiology, grafting materials, implant design, and load distribution factors has shown that success in bone plastic surgery can be increased. Achieving the maximum aesthetic and functional effect begins with the correct installation of the implant. Thanks to modern technologies of autotransplantation of bone blocks, it is possible to restore the crest, even if it has undergone significant resorption.
Some studies in the field of implantology show a better prognosis when installing an implant in a bone mass of sufficient parameters than when installing an implant in the hole of a removed tooth or in an area with insufficient bone with simultaneous bone growth.
Why is bone augmentation performed during dental implantation
Delayed placement of implants after some time after the build-up has a number of advantages: the presence of sufficient bone tissue the ability to install the implant in the “correct” orthopedic position ensuring better fixation of the implant ensuring better contact with the implant coating due to greater bone density.
The survival rate of an implant depends directly on the biomechanics of its condition in the jawbone. The biomechanical distribution of stress load is carried out at the point of direct contact of the bone tissue with the implant. The higher the bone density, the better distributed the load. Since the maximum load is on the area of bone around the base of the implant, bone grafting, ideally, should lead to the appearance of the bone with sufficient density to adequately resist the load. If there is a need to restore a significant deficit of bone tissue,then the most effective will be a bone autograft graft. From intraoral sources of bone blocks, two areas are distinguished: the chin symphysis (the Central part of the chin located below the roots of the front lower teeth) and the angle and branch of the lower jaw (the space located behind the lower wisdom tooth, outside it and above). The use of intraoral donor sites is associated with both the same type of embryonic origin of the bone, and the cheaper procedure compared to hospitalization and anesthesia when taking bone from the iliac pelvic bone.
Most often, a bone block of sufficient size can be transplanted from the chin area to increase the ridge of the required width in the area of four teeth, as well as a block in order to restore the ridge in the area of two teeth, if it is necessary to increase the alveolar process in both width and height. A slightly smaller area can be restored with a block from the corner and branch of the lower jaw.
The process of building up bone tissue
The method of intervention is as follows. A block that is comparable to the size of the area being restored is taken from the donor site. In the receiving bed, mini-holes are made, through which new vessels will grow into the block — for better blood supply to the block. The block is screwed to the receiving bed using special screws, and the space between the block and the receiving bed is filled with either autogenous bone chips (obtained when the block was taken) or a bone substitute. The block with the graft material is either covered or not by an insulating membrane, depending on the technology used by the implantologist. Then both zones are carefully sewn – both where the block was taken and where it was installed. Complications such as divergence of the wound edges and exposure (cutting through the gum) of the autograft are more common in smokers, so patients should refrain from Smoking during the treatment period. It is undesirable to wear a removable temporary prosthesis based on an autograft. After 4 months, implants can be installed in this area.
Block sampling can also be performed to obtain bone chips. If an intervention is performed in which the volume of the material to be inserted is quite large, usually crushed own bone is added to the bone-substituting materials. Bone chips can also be used for sinus lifting, when building up the alveolar ridge in height with simultaneous installation of implants.
Bone augmentation: reviews and answers to questions
Often patients are very concerned about what their chin will look like after such an operation. Incomplete restoration of bone tissue in the chin area will not lead to external changes in the face profile. Some experts do not recommend replacing the donor site with osteoplastic material, and this does not affect the change in the contours of the chin area. As for the angle and branch of the lower jaw, the installation of a collagen sponge is sufficient in the area of the donor site. Of course, in each individual case, you need to discuss this issue with your implant surgeon