CAD/CAM international magazine of digital dentistry

06 I I CE article _ application of 3-D imaging _For nearly 100 years, dentists have relied on 2-D radiographic imaging for diagnosis and treat- mentplanning.Withthe1999introductionofcone- beam computed tomography (CBCT), all dentists now have tools available for more accurate diag- nosis and treatment.1 The ability to look at a tooth in any direction and orientation, as well as in 3-D, eliminates much of the guesswork commonly experienced with 2-D radiographs. Wehavebeenlimitedinmostcasestoonlyabuc- cal-lingual view provided by periapicals, bitewings and panoramic radiographs with the occasional axial view of an occlusal film. Medical CT scans and images began in the early 1970s and were some- timesusedbydentists,offeringourfirstmultiplaner views.2 The adoption of 3-D cone-beam imaging is ap- propriate and has important advantages for all modalities of dentistry. From every specialist to the general dentist, the increased amount of radi- ographic information as well as increased accuracy will aid in the most sound diagnosis possible. _CBCT description CBCT is a single or partial rotation of an X-ray source around the head, capturing X-rays on vari- ous flat panel arrays and sensors. The information is converted to a series of axial slices by computed tomography and stored as virtual anatomy in the computer. With the use of sophisticated software, the den- tist is able to view information in several different views, including: axial slices (head-to-toe orien- tation), coronal slices (front-to-back orientation), saggital slices (side-to-side orientation) all known asmultiplanerreconstructions(MPR).Thethickness of each slice can be varied to include more or less information. Because the voxels (volumetric pixels 3-D) are isotropic, other MPR images can be generated by slices drawn at any angle, curve or thickness through the scan to view areas critical to the final diagnosis.3,8 The final view offered by CBCT is a 3-D view that can be rotated and viewed in any direction. CAD/CAM 4_2012 Fig. 1_Saggital CBCT MPR showing bone defect at point of dehiscence of the implant coating. Fig. 2_Periapical does not show the sinusanatomyorthewidthofthebone. Fig. 3_MPR showing post-op of sinus graft and implant placement. Clinical and diagnostics advantages of PreXion 3-D imaging system Author_ Dr Dan McEowen, USA Fig. 1 Fig. 2 Fig. 3 By reading this article and then taking a short online quiz,you will gain oneADA CERP CE credit.To take the CE quiz,visit www.dtstudyclub.com.The quiz is free for subscribers,who will be sent an access code.Please writesupport@dtstudyclub.com if you don’t receive it.Non sub- scribers may take the quiz for a $20 fee. _ce credit CAD/CAM