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12 I I case report _ 3-D diagnostics positioning so that the relevant structure is ac- curately captured. For new users and those who only take volume tomograms once in a while, this correct setting can pose difficulties, which was our motivation for developing a DVT phantom that can be used for training purposes and for direct preparation of an image with a patient. _The DVT phantom and its application The DVT phantom is an X-ray phantom that depicts a medium-sized mandibular and maxil- lary dental arch with the teeth positioned in ideal denticulation. The phantom, which consists of a mandible and maxilla, is mounted on the individual bite or positioning support of the respective device. Barium sulphate is added to the plastic teeth so that they are visible in the X-ray image. These teeth are made by the manufacturer especially for X-ray applications. The DVT platform is then mounted on the device with the original bite support instead of a patient. The device setting can be done in two different ways: a) The desired volume is preset using the device programme and then manually fine-tuned. b) The device is manually set directly upon the region to be captured with the aid of the light visors. Thereafter, the set positioning is saved. Using the DVT phantom for training and practice WiththeaidoftheDVTphantomandtheabove- mentioned setting techniques, new users, who are training to become dentists or dental technicians, can learn how to set the device for the regions to be examined, generate one or more individual images using the preview func- tion and check whether the setting was correct. In the event of incorrect settings, a better image can immediately be generated. In this manner, there is a direct learning curve. Using the DVT phantom for preparing a patient image Time-consuming and te- dious setting (aiming) of the DVTonapatientwhoisalready in the device is likely to be uncomfortable for the patient. This is where presetting the device with the aid of the DVT phantom comes in handy. The desired region is captured with the phantom and, if needed, is checked with the preview function. Then, the phantomisremovedandthepatientispositioned in the device. Generally, only one device setting for the patient’s body size and small fine-tuning are required before the image is set. _How to obtain a DVT phantom A DVT phantom can be produced in cooperation with practising dental technicians. The plastic teeth containingbariumsulphateareavailableonthemar- ket and a phantom can be made in the manner de- scribedabove.AneasieroptionistosendaDVTposi- tioningaidofyourdevicetodtcmfreiburg@aol.com or through www.dtcmfreiburg.de. Master Dental Technician Christian Müller will then mount a pre- pared DVT phantom on your positioning aid. In- dustrially manufactured plastic teeth containing barium sulphate (SR Vivo Tac/SR Ortho Tac, Ivoclar Vivadent) will be used, which are then incorporated into a mandibular and maxillary model made of transparent plastic. Wehopethatthefascinatingfieldof3-Ddiag- nosticswillestablishitselfquicklyindentistryand remain an imaging procedure that significantly expands upon the hitherto range of dental X-ray diagnostics in the long term._ CAD/CAM 2_2010 Fig. 4_DVT phantom image of the maxilla with the DVT phantom. Fig. 5_DVT phantom image of the mandible with the DVT phantom. Dr Georg Bach Rathausgasse 36 79098 Freiburg/Breisgau Germany doc.bach@t-online.de CAD/CAM_contact Fig. 4 Fig. 5