CAD/CAM international magazine of digital dentistry

feature _ interview I _What impact has CAD/CAM technology had on the usage of aesthetic restorations in the dental practice? With CEREC, CAD/CAM technology has been available for chairside application for more than 27years.Sothisisawell-documentedprocedurewith long-term clinical success. Today, there are approxi- mately 34,000 CEREC units in use, which demon- stratesimpressivelythatthistechnologyisstilldriving aesthetic dentistry in the clinical practice. The main indications are inlays, onlays, partial crowns, full crowns and veneers. In addition, up to four-unit pos- terior bridges are now possible, either as a temporary solution with polymer blocks (e.g. Telio CAD, Ivoclar Vivadent) or as a permanent restoration with a high- strength zirconium dioxide/lithium disilicate material (e.g.IPSe.maxCAD-on,IvoclarVivadent). _What are the aesthetic limitations of chairside CAD/CAM? Generally, posterior restorations like inlays, onlays and crowns can be realised with good aesthetic re- sults. With anterior restorations like crowns and ve- neers, the aesthetic outcome largely depends on the adjacent teeth that we have to match intra-orally. Highly aesthetic colour gradients for CEREC restora- tions can be achieved with polychromatic blocks (e.g. IPSEmpressCADMulti,IvoclarVivadent)orbyshading and staining monochromatic lithium disilicate blocks (e.g.IPSe.maxCAD,IvoclarVivadent). All this can be carried out by the dentist chairside. If the adjacent teeth show visible internal structures like mamelons, dentists need the support of dental labtechnicianstooptimiseaesthetics—thisrepresents theaestheticlimitationofchairsideCAD/CAM. _Have restorations become more complex with chairsideCAD/CAM? On the one hand, yes, the procedure has become somewhat more complex because the dentist is also responsible for the design, milling and surface fin- ishing of the restoration. On the other hand, im- pressions and temporaries are no longer necessary, which makes life easier for both the dentist and the patient. _What are the critical factors for achieving suc- cessfullong-termclinicaloutcomes? In addition to the factors described above, cemen- tation, particularly for glass-based ceramic restora- tions, is a clinical step of paramount importance for long-term clinical success, since it is directly linked to theaestheticoutcomeandthefracturestrengthofthe final restoration. Which ceramics have to be bonded? Which ceramics can be cemented conventionally? Howdoesonepreventpost-operativesensitivityafter cementation? All these questions will be answered in detailduringthelecture. _Many speak of CAD/CAM technologies as the nextrevolutionindentistry.Doyouagree? I would say that the revolution will continue. I am still fascinated by the materials and the manufac- turing process. All-ceramic restorations are not only aesthetically pleasing but also minimally invasive. Therefore, patients benefit not only from better look- ing teeth, but also from the fact that much less natu- raltoothsubstancehastoberemovedcomparedwith traditionalrestorativetechniquesandmaterials. ThenextfewyearswillshowwhatCAD/CAMman- ufacturers have kept in reserve, both chairside and labside.MaterialsmanufacturerslikeIvoclarVivadent will continue to develop highly aesthetic and user- friendly all-ceramic systems that aim to further re- ducetheminimummaterialthickness—requiringeven lessinvasivetoothpreparations—tothebenefitofthe patient. _Thankyouverymuchforthisinterview. I 13CAD/CAM 3_2012 “...cementation is a very important factor and still underestimated by many dentists.”