These images demonstrate the thickness, the form and the height of the alveolar arches, as well as the cortical ssea. The anatomical accidents, as incisive canal, must be demonstrated and be saved during the surgery. The quality of the fabric sseo is evaluated through the measures of its demographic density in Unidades Hounsfield (UH). According to Pasler & Visser (2001), the anatomical structures are represented in the x-rays in different ash tones. The Computerized Cat scan makes possible the variation of 4.096 ash tones. For the creation of ' ' janelas' ' in the monitor, 256 ash tones can be obtained in regions as soft bones or parts, becoming them more visible.
As the visual perception human being of the colors does not correlate itself with the ash tones, not yet can be developed a codification of colors desired and including. In accordance with Cala et al. (2001), the ssea density influences the surgical technique, the time of cicatrizao, the initial interface bone/implantation and the gradual load rank during the prosthetic reconstruction. Being thus, the previous knowledge on ssea density becomes an indispensable factor for a correct planning and execution of dental implantations. On the other hand, for Renouard & Rangert (2001), the ssea density is a difficult parameter of being evaluated. It varies, substantially, of an anatomical region to another one and can vary very, exactly inside of one same operatria zone. However, the knowledge of the ssea density is extremely important to establish the treatment plan. The failure index is bigger for regions with density very low (primary stability decrease) or regions with very high density (risk of overheating during the preparation with drills). Wolfsohn (2001) called the attention for one the biggest obstacles that have in the practical implantolgica, that is the risk of injury to some nervous structure during the incisions, the displacement or the installation of the proper implantation.