Digital Dental CAD/CAM Milling Units


There are many milling machines on the market that can perform a variety of different tasks but they are not for everyone. Some systems, particularly those sold as complete systems that include the scanner, design software, and milling unit, are optimized to work in an integrated fashion so that the user does not have to fine-tune each component to obtain the desired milled fit. There are also milling machines and components that can be purchased as stand-alone units but need work to dial in the accuracy and detail of the fitted end product. Today, most of these milling units are nearing “plug and play” operation but typically need some sort of tweaking by the customer.

sirona x5 2

For many years, 3- and 4-axis milling had been the industry standard for two reasons. The first was that dental work rarely needed milled structures with undercuts, and the second was that 5-axis machines were too big and expensive. Today, 5-axis machines are much smaller and more affordable. The surface quality of the units milled in a 5-axis simultaneous milling machine is much better and allows for better detail and contours. However, the downside to producing greater detail and a better surface finish is that it takes longer to produce the final product. Milling, or subtractive production, also is a wasteful process. The author weighed out a single-unit, partially sintered milling block at 10 g. After milling, the final milled unit weighed a mere 0.3 g, which represents 97% waste. Currently, milling technology is the only way to fabricate zirconia-based restorations, but that may change. Other considerations that add cost to producing a final product with milling technology are tooling wear (burs) and the liquids and/or filters for vacuum systems. These all add cost to the final product.

Digital dentistry is the future of our profession. The driving force in the operatory will be an educated patient base demanding a digital alternative to conventional impression-taking techniques and materials. As more dentists understand the benefits of digital tools and processes and the cost of the technology drops, digitization will progress even faster. The driving force in the dental laboratory has been the rising cost of labor, the challenge of skilled labor resources, and competition from overseas. Emerging CAD/CAM technologies hold promise to help our industry become even more productive and competitive in this open market. Technologists must recognize these driving forces, envision the future, and navigate through the web of CAD/CAM systems to prepare their businesses to better accommodate the expectations of patients and clients for restorations that exhibit the amazing detail, consistency, and accuracy that this technology offers.