Lab Tribune U.S. Edition, November 2010, Vol. 1, No. 61

LAB TRIBUNE | November 2010 Events 3D AD technicians and surgery staff can opti- mally acquaint themselves with the state of the art in digital technology and receive advice from manufacturers at the International Dental Show (IDS), which takes place in Cologne, Ger- many, from March 22–26, 2011. The CAD/CAM supported manu- facture of dental restorations involves appropriately preparing the surfaces of the teeth involved for the materials to be used, then digitally acquiring a three-dimensional image of the sur- faces of these teeth and possibly also neighboring and antagonist teeth so that the data can be processed using computer support. This can alterna- tively be accomplished by means of intra-oral digitization, in which case a conventional impression of the clinical situation is not required. Over the last years, the dental indus- try has developed innovative optoelec- tronic equipment systems for the non- contact intra-oral acquisition of the surfaces of the teeth. These systems can combine a large number of indi- vidual measurements of spatial coordi- nates of the preparations or teeth taken from different angles under the special, particularly difficult conditions of the oral cavity to create a complete model dataset. Such model calculations some- times also require corrections — due to the individual soft-tissue status or f LT page 1D because of the different translucence of the tooth surfaces — to be applied in order to ensure the necessary measure- ment accuracy. The classical route to a digitized model via impressions taken using high-quality materials continues, today and in the future, to offer an alternative to the non-contact intra-oral processes. A master model is created extra-oral from the impression and then optically scanned to acquire the three-dimen- sional image. Nowadays, a wide range of precision laser scanners and purpose-developed CAD software is available for this task. These systems can also be optionally linked to and expanded using new developments in imaging processes. Today, the practitioner has available an entire range of powerful imaging techniques and user-friendly software which, thanks to the international DICOM standard, is compatible and interoperable between manufactur- ers. Computer tomography and dig- ital volume tomography, which can for example be used for carrying out implant planning precisely on-screen, are particularly worthy of mention here. Current digital planning methods strengthen the already close coopera- tion between dentist and dental techni- cian in prosthetic or implantological therapeutic measures. Modern CAD programs calculate complex clinical situation surfaces from the digital data on tooth stumps, implant posts or plaster models. Occlu- sal features of antagonists or neighbor- ing teeth can also be created on the computer, all the way to complete con- tact point patterns. Individual functions such as an undisturbed free glide space can be elegantly designed and imple- mented in crown-and-bridge frame- works by means of CAD/CAM and CNC milling technology. CAD/CAM technology has avail- able a constantly growing palette of materials including the oxide ceramics — primarily zirconium dioxide — and titanium and cobalt-chrome alloy, both of which are increasingly being used for milling frameworks. The division of labor between the dental laboratory that handles the design and the exter- nal industrial milling center suitable for the technically demanding processing of the metal materials has proven itself in this area. Specialized companies now even offer the design and manufacture of complex post- or bridge-supported superstructures, in which case the commissioning laboratory can then concentrate entirely on the subsequent finishing work in ceramic or plastic. In addition to these subtractive, indi- rect processes that use CAD/CAM to manufacture dental prostheses from material blanks by removing material, additive, direct processes are also used in dental prosthetics. So-called rapid prototyping technologies enable a cast to be made in various ceramic, plastic or metal materials directly from the CAD program. Modern processes such as laser sintering, stereolithography or fused deposition modelling can build up the necessary layers of material successively and with high precision until the final form of the restoration has been reached without the need to manufacture a mould in advance. Den- tists and dental technicians will have a unique opportunity to gain a compre- hensive overview of the latest concepts in dental CAD/CAM technology during their visit to the IDS 2011. “From March 22–26, the Interna- tional Dental Show in Cologne — the world’s largest trade fair for dental medicine and dental technology —will provide trade visitors from dental prac- tices and dental laboratories an ideal opportunity to talk to specialists from exhibiting companies, experts and experienced users. Here, they will be able to address the whole spectrum of modern CAD/CAM processes and current developments in dental digital technology,” said Dr. Markus Heibach, president of the VDDI. IDS takes place in Cologne every two years and is organized by the Gesell- schaft zur Förderung der Dental-Indus- trie GmbH (GFDI), the commercial enterprise of the Association of Ger- man Dental Manufacturers (VDDI) and staged by Koelnmesse GmbH. LT