cone beam international magazine of cone beam dentistry

I case report _ dental implantology teeth were widened to create more space for the implant abutments. The completed set-up (Fig. 9) was crucial in demonstrating the potential final re- sults and determining the position of the implants. The parameters specified here must not be changed to accommodate both the surgical and restorative phases of treatment. The set-up is therefore also known as the “point of no return”. These steps repre- sented the analogue or conventional method of cre- atingthediagnosticwax-up. The completed set-up was sprayed to facilitate digitalisation of the cast utilising an open laboratory scanner (SinergiaSCAN, Nobil-Metal; Figs. 10–13). The model of the patient’s initial oral condition and theedentulouscastonwhichtheset-upwascreated werebothscannedforincorporationintotheimplant planning software. The CBCT scan DICOM data was first imported into the SIMPLANT interactive treat- mentplanningapplication(DENTSPLYImplants).The digitalworkflowcontinuedwiththeimportofthevir- tual STL files of the digitised stone models (Figs. 14a–c). The STL 3-D volumes were then combined withthepatient’sCBCTimagesintheSIMPLANTsoft- ware,usingtheOpticalScanmodule(Fig.16).Thesep- arate datasets are accurately superimposed or com- bined to allow for improved diagnostics, as they can be easily manipulated by the software. The surface detail of the digitised stone casts and wax-up is far superiortothesurfacedetailoftheCBCTscanimage. Using the interactive implant treatment plan- ning module, eight implants were simulated in the patient’s bone, each with a virtually elongated axis that helped demonstrate parallel positioning in relation to the proposed restoration as rep- resented by the diagnostic wax-up. In order to achievethedesiredsurgicalandrestorativeresults, various technical aspects must be considered. The length and width of the implants in the bony receptor sites must be sufficient for implant sta- bilisationandeachimplant’sscrewaccesschannel should ideally end in the middle of the planned tooth for a screw-retained prosthetic design (Figs. 16–22). Figures 23 to 26 show the patient’s jaw before and after tooth extraction, along with the prosthetic design and the axis projection of the simulated implants. Owing to the number of extractions in this case, the surgeon opted for a bone-supported surgical guide. Using specific software segmen- Fig. 19_Cross-sectional view with teeth and implant in place. Fig. 20_The plan in the panoramic view. Fig. 21_The plan in the axial view. Fig. 22_Virtual 3-D view. A virtual set-up was not used, as it is difficult to understand in such a large case and the end-result is not necessarily better. Fig. 23_The teeth to be extracted, with bone structure, viewed in the design software. Fig. 24_After virtual extraction of the teeth viewed in the design software. Fig. 25_The improved situation, scanned and matched in the design software. Here the gingiva and bone structure can be seen. This can be achieved by including model data in the project. Fig. 26_Parallel elongation of the implant axis. 18 I cone beam2_2014 Fig. 19 Fig. 20 Fig. 24 Fig. 26Fig. 25 Fig. 21 Fig. 23Fig. 22