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ePaper created 2018-03-26, 09:23:37 | version 1.38.0
14 TRENDS & APPLICATIONS Dental Tribune Asia Pacifi c Edition | 1+2/2018 Mastering the implant digital workfl ow Dr Ross Cutts, UK Whether we like it or not we are embracing the digital era in our brave new world. Many dental practices are now becoming paper free—a digital innovation—and even using tablet computers to re- cord patient details and medical histories. We are continually sur- prised by the rising age of the tech- nologically savvy patient, particu- larly those of a certain generation that perhaps we assume to be less “digital” than the perceived smart- phone generation. This change in patient demographic and attitude towards technology is fi ltering through to us in the dental profes- sion. Dental implantologists tend to lend themselves more readily to the digital revolution of den- tistry in the UK and globally. Many practitioners opposed to or reluctant to embrace it, are actu- ally being infl uenced by it from shifting workfl ows in dental labo- ratories even where more tradi- tional clinical practices are fol- lowed chairside. Quite often wet impressions are poured, and stone models are scanned to pro- duce digital stereolithography (STL) fi les for laboratories to pro- cess during crown and bridge unit manufacturing. As an implant clinician you do not have to invest in a com- puter tomography (CT) scanner or chairside intraoral scanner— there are ways that other centres and laboratories can provide these services—however having these tools at your disposal greatly increases your effi ciency and you are not relying on exter- nal services for your patients. So how do we begin the im- plant digital workfl ow? ment and planning of the pro- posed restoration. This is impor- tant for all cases not just what we deem the complex ones, even the most experienced implant placer can miss a potential treatment planning hazard especially dur- ing a busy day. Accurate study model casts are an essential part of this, how- ever we can now use intraoral scans preoperatively to begin the digital workfl ow. We take a scan rather than impressions to form digital models. Our laboratory can then use these to create digi- tal wax-ups of proposed treat- ment outcomes (Figs. 1 & 2). We are routinely used to 2-D radiograph imaging techniques within dentistry but with the availability and access to cone beam computed tomography (CBCT) scanning devices now we are able to assess bone quantity and quality of proposed implant surgical sites (Figs. 3 & 4). With ever reducing doses of 3-D imag- ing and improving accuracy we have the option to use CT scans combined with clever software packages such as coDiagnostiX™ (Dental Wings) to plan safe and accurate implant placement and restoration. We are able to preop- eratively plan precise implant placement with safe surgical margins away from important anatomical structures such as the inferior alveolar nerve or maxil- lary sinus. From this we are then able to design and either mill or print a surgical guide to use for precise placement (Figs. 5–7). implant Surgical treatment phase 1 2 3 4 Fig. 1: Intraoral scanner. — Fig. 2: Printed models. — Fig. 3: 2-D radiograph. — Fig. 4: 3-D radiograph. Treatment planning Successful implant treatment begins with thorough case assess- Even with assisted or guided surgery there are sometimes cer- tain restrictions that prevent us from achieving the most ideal implant placement, such as in the case presented here, where poste- rior access in the second molar region is reduced, making it ex- tremely diffi cult to achieve the perfect parallel (Figs. 8 & 9). 6 7 5 Fig. 5: coDiagnostiX™ screenshot. — Fig. 6: coDiagnostiX™ screenshot of guide production. — Fig. 7: Printed surgical guide. There are fully guided sys- tems available which allow for ab- solutely precise implant place- ment, but these are fraught with complexities and should be re- served for experienced placers. The accuracy of surgical guides should not be used to make up for a lack of surgical competency. There are many factors to be considered when using surgical guides, depending on whether the guide is tooth-, soft-tissue- or bone-supported. Tooth-sup- ported allows the greatest degree of accuracy. mobile? Any mobility adds a degree of inaccuracy. – Is the guide made from a direct intraoral scan or a scan of a study model? If scanning a study model, would this be an accurate stone model rep- resentation? Otherwise one could risk poor seating and in- accuracy of the guide. If soft-tissue-supported: Mobility completely negates any accuracy of the guide, so it should only be used for a pilot drill and then a more conven- tional surgical protocol should be adopted. If bone-supported: – Raising a very large surgical fl ap is likely. If tooth-supported: – Are there windows in the guide which demonstrate full seating of the guide? – Are the teeth which support exact positioning of the guide – It is very diffi cult to get accu- rate full seating of a bone- supported guide in the precise planned position, thus one has to rely upon external fi xa- tion.