CAD/CAM international magazine of digital dentistry No. 4, 2016

IDS meetings | 55 CAD/CAM 4 2016 laboratories in order to exploit their own systems to the full and laboratories that offered round- the-clockownproduction,whoalsoadditionallyout- sourced parts of the production, established itself. Currently, some laboratories are asking themselves about the optimal implementation of 3-D printing: Drilling templates, different splints, dental technol- ogy models, individual impression trays and plastic basecastsforthemetalcastdepictthemostfrequent indications.Whethertheyareorderedfromanexter- nal service provider or produced in one's own firm, is determined by the amount of the orders to be expected and the speed required by the customer, where own manufacturing principally allows imme- diate production. IDS 2017 shows which technolo- gies are available and how to invest in them—and thusfacilitatesanindividualeconomicalcalculation. The extended range of printing methods In addition to the methods already mentioned, among others the so-called multi-jet technology (detailed work up to precisely 16 micron), the fused layer techniques (fused deposition modelling, FDM; fused filament fabrication, FFF) and the mask expo- sure method prove to be interesting. The multi-jet technologyworksfollowingtheprincipleofthe"ink- jet printer". For example, (almost) two-dimensional layers of powder are rolled out and then imprinted with bonding agents—exactly on the places where thedentaltechnologyitembelongsaccordingtothe constructionplan(=virtualmodel),thenon-bonded power can be simply removed. The material used is either glass or metal powder, whereby with today's currentstateoftechnologyonlythemetalpowderis suitable for the production of solid objects, because to this end after the printing process, a sintering and an infiltrating step to fill up existing cavities have to subsequentlybecarriedout.Alternatively,oneprints (once again almost) two-dimensional photopoly- mers according to the construction plan and lets themhardensothattheitemisformedlayerbylayer. Using the layer melting technique one extrudes for example waxes or plastics out of a nozzle or ap- plies the material drop by drop, once it cools down it solidifies—then the next layer can be applied. Finally, the mask exposure method works similar to the well-known stereolithographical technique. The decisive difference: Instead of using a laser, the plastic is hardened with the aid of a UV LED lamp. 42016

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