CAD/CAM - international magazine of digital dentistry

I 23 case report _ guided implantology I CAD/CAM 2_2013 read-out of borders between hardandsofttissue(Figs.6–8) and the digital implant place- ment under the crown in such a way that the future connec- tion of the implant and crown usinganabutmentisprostho- dontically possible (Fig. 9). After the digital implant had been imported into GALAXIS, the need to use CEREC Guide (or another guided-surgery technique) became apparent in this case owing to a drama- ticconicalapicalnarrowingof therootsoftheadjacentteeth 14 and 13 in the intended implant space (Fig. 10). Owing to the lack of space between these roots, we chose a 3.3/8 mm implant (SwishPlus, Implant Direct). After digital implant placement, we select to continue and edit the sleeve system. After selecting this option, a new dialog box marked “reference body” appears. On this screen, we mark the fiducial points using the lever underneath the image and move the lever until the fiducials appear to be as round and clear as possible. Finally, we double click on the threemostclearfiducialpointsandthesoftwarewill then automatically search for and determine the remaining fiducials (Fig. 11). Next, we confirm that the fiducials have been found and the reference body appears on the 2-D and 3-D images (Fig. 12). In order to better visualise the interaction of the drill path and drill body with the implant, the final drillpathandpilotdrillpathmustbeturnedoninthe 2-D views (Fig. 13). The reference body must fit exactly within the drill path in order to be milled. The most important part of CEREC Guide pro- duction is setting the D2 value. The D2 value, also known as the drill stop length, is the distance from the apex of the implant to the top of the guide. Ifwemeasurethelengthofthedrillfromitscutting tip to the drill stop, the D2 value will be that length minus 1 mm, which is the thickness of the implant guidehandle.Inourcase,forthe8mmimplantused, this value was 23 mm (the 24 mm drill minus the 1 mm handle). The D1 value changes with the D2 value automatically (Fig. 14). Inordertocontinue,weexportthisarrangement data back to the CEREC AC unit as a *.cmg or *.dxd file.AfteropeningthecorrectfileinCERECSoftware 4.xx,thedrillbodyproposalwillappearinthemilling preview (Fig. 15). Now we can place the appropriate block size (in our case this was “M”) into the milling unit(MCXLoninLabMCXL,Sirona)andselect“mill”. Fig. 22Fig. 21 Fig. 20Fig. 19 Fig. 24Fig. 23