CAD0110

34 I I industry report _ NobelProcera _Today, dental technicians and general practi- tionersarechallengedbyanever-increasingnumber of CAD/CAM systems in the dental market. In order to determine which system is best suited, various aspectsneedtobeconsidered.WhileCAD/CAMtech- nology was initially associated with zirconia-based restorations, advanced systems offer an extensive range of materials and solutions for both natural teeth and implants. The benefits are not limited to a morecost-efficientfabricationofdentalrestorations in the laboratory; practitioners and patients benefit from the technological advancements equally. This article discusses the various aspects that need to be considered in the decision-making process. _Simplicity in clinical and laboratory routines A key aspect of the successful application of new technologies and clinical protocols is the time required to adapt to and utilise a system in a daily routine. This aspect is not only of relevance for the dental laboratory in manufacturing a restoration, but also to the practitioner considering changes in clinical protocol. Simplicity for the dental techni- cian primarily concerns the time required to design and manufacture a restoration. However, in order to ensure an efficient workflow, a user-friendly software interface and intuitive handling are also of utmost importance. Current scientific findings and clinical experi- ence underscore the need for adequate material manufacture and framework design to minimise clinical failures, such as chipping of veneering ce- ramics or fracture of frameworks. The most impor- tant request, especially when working with zirconia substructures, is that the framework be anatomi- cally designed and require no manual post-pro- cessing adjustment. In the past, double scans were performed in order to achieve this goal. New soft- ware design tools eliminate these time- and cost- intensivesteps,asanatomictooth-librariessupport the user in ideal coping and framework design. Automatic cut-back functions increase ease of use and provide an additional margin of safety by en- suring homogenous veneering material thickness. An equally important aspect to consider is the de- sign and dimension of the connector cross-section for fixed dental prostheses. Only if minimum con- nector dimensions are respected will long-term clinicalsuccessnotbejeopardised.Newlydeveloped softwaretoolssupporttheuserinthevirtualdesign oftheframeworksandprovideimmediatefeedback on the cross-sectional area, connector height and width, and coping thickness. The most eminent facts for the practitioner are that no major changes in clinical protocol are re- quired when working with CAD/CAM technology and industrially manufactured components. Only when it comes to oxide ceramics are slight modi- fications of preparation design required for long- term success. These are limited to a slight chamfer margin preparation, provision of an adequate oc- clusal space of 1.5 to 2 mm and rounded edges (eliminating sharp transitions). The true benefit when working with materials such as zirconia or aluminium oxide is that conventional cementation protocolscanbeapplied.Adhesiveluting—arequire- Figs. 1a & b_Application of zirconia for long-span restorations requires high manufacturing precision and excellent material quality. Only if colouring pigments are equally distributed in the framework will material properties be optimal. CAD/CAM 1_2010 Safety and reliability with CAD/CAM technology Authors_ Hans Geiselhöringer & Dr Stefan Holst, Germany Fig. 1a Fig. 1b