Computer aided surgical guide
Digital revolution is the shift from mechanical and analogue electronic technology to digital electronics with the adoption of computers, and it is rapidly transforming the world. Today, computers and digital devices are inevitable part of our daily life, and dentistry is no exception. Dentistry has recently been dominated by various digital technologies such as cone beam computed tomography (CBCT), computer aided design and computer aided manufacturing (CAD/CAM), stereolithography, intraoral scanners, and 3-dimensional (3-D) implant planning software for virtual implant treatment planning and surgical guide fabrication. To overcome the limitations associated with conventional radiographic surgical stent, computer aided surgical guide have been evolved. A computer generated surgical guide provides a link between our treatment plan and the actual surgery by transferring the simulated plan accurately to surgical site. This surgical guide is made using stereolithography process and is custom manufactured for each patient.
Stereolithography, a rapid prototyping technology, a newer outcome in dentistry allows the fabrication of surgical guides from 3D computer generated models for precise placement of the implants. The surgical templates fabricated by this technology are preprogrammed with individual depth, angulations, mesiodistal and labiolingual positioning of the implant.
Fabrication of computer aided surgical guide requires CBCT images. In CBCT, multi planar reformatting allows one to reformat a volumetric dataset in sagittal, axial, and coronal planes and also helps in building multiple cross-sectional and panoramic views. Shaded surface display and volume rendering methods generate 3D reconstructions of the entire dental arch and their relevant structures, including nerves, which makes dental CBCT the most precise and comprehensive radiologic technique for dental implant planning. Software′s specially planned has been adapted to allow practitioners to virtually view the implant site and plan location, angle, depth, and diameter of virtual implants, which are superimposed on the 3D data.
Computer guided implant placement by using the information from CBCT imaging, 3-D implant planning software and stereolithographic surgical guide has recently become a popular treatment modality. Moreover, this technique allowed flapless implant placement, which offers a few advantages such as shorter surgical time, faster recuperation, less post-operative pain and swelling, and better esthetic outcomes.
Requirements for CAD/CAM surgical guide
- CBCT scan (fig.2)
- PVS impression or Intraoral scan (fig.3)