Ammerbuch/Hauppauge, November 13, 2019: A recent scientific study at the University of Washington proved a key feature of the Z4. Using the milling and grinding machine, one can drill screw-access channels for hybrid implant restorations into ceramic blocks with no significant difference in flexural strength compared to factory-fabricated materials. In fact, these pre-drilled “meso” blocks are significantly more expensive, and the nesting process is much more complicated.
The purpose of the study was among others to compare screw-access channels that were prefabricated under factory settings and channels milled in a Z4 from vhf. For this, a variety of CAD/CAM ceramic materials from different manufacturers was evaluated. The study ultimately proved that there is no difference in the flexural strength of both materials. The more expensive “meso” milling blocks, therefore, do not result in restorations with significantly less milling damage than solid milling blocks. Thus, processing standard blocks with the Z4 means less cost for material and less material inventory necessary. The authors of the study are Jack M. Keesler, DDS, MSD under guidance of the renowned John A. Sorensen, DMD, PhD, FACP.
The CEO of vhf Inc., Nicolas Rohde, PhD, appreciates the study results: “This is good news for users of milling machines such as the Z4 and a convincing argument for those who are thinking of purchasing this vhf machine. Our customers can conveniently finish perfect restorations by drilling screw-access channels in highest quality. Likewise, they are working very cost-efficient – a true show-stopper!”
The Z4 is a four-axis, high precision milling and grinding machine with an integrated PC and requires no additives for the water-cooling system. Developed for same-day dentistry, it enables patients to receive high-quality restorations much faster. The block material is fixed without tools and can therefore be exchanged in seconds. For the study, two fine-grained diamond radius tools from vhf, were used for grinding the channels.