There are open and closed CAD/CAM systems. Closed means you have limited choice when it comes to elements of the CAD/CAM solution. Open means you can pretty much change anything in the list. It has always been Roland’s policy to be as open as possible. You can use any scanner and CAD, so long as you can output an .stl (Stereo lithography) file, which is an industry-standard format. More importantly, you can feed your DWX milling machine with materials from your chosen supplier. This freedom maximizes competitiveness and keeps you in control of your production costs.
Just like milling equipment and restoration materials, scanning technology has also improved dramatically in terms of speed, accuracy, ease of use and versatility. Scanners are usually supplied together with the CAD software, so you need to consider both when choosing a scanner. Lab scanners either use a laser beam to scan a model, or project light and then measure the pattern generated. Higher priced models tend to offer greater productivity through speed and multiple die scanning. Some can scan impressions directly, creating a virtual model onscreen. This means that the model can be produced by either a milling machine or 3D printer at the same time as the restoration is being milled. Sometimes, you may not need a model at all.
It is the CAD software which allows you to construct the restoration from the scanned model or impression. Some CAD providers claim that it can take just 90 seconds to design a coping and make it ready for production. Virtual articulation, coupled with impression scanning, offer the possibility of model-free workflow. Whether you are creating a coping, full contour crown, bridge, inlay/onlay, partials or implant bar, CAD software has been optimized to make the process familiar and intuitive for dental technicians.
Once your design is complete, you need to prepare it for milling. The CAM software allows you to select your desired material, whether it is a new or part-used block. You can either manually position your designs, or let the software orientate and locate to minimize material waste. Equally, supports can be placed manually or automatically. The CAM software analyses the geometry of the required restorations and assesses the optimum tool path strategy for the material and the tools (burrs) available.
The operator loads the required material and fits the tools specified by the CAM software. The DWX50 and DWX4 will automatically change tools to complete the restorations without manual intervention. The milling machine then receives the instructions from the CAM software and follows the tool paths. Out of the entire CAD/CAM workflow, milling is the one truly automated part of the process. Once loaded, the operator is free to get on with the next batch of scans to start the process again. The DWX can even be configured to email you when it is finished!
Zirconia restorations are milled in a pre-sintered state. This means that the material is relatively soft, so cutting time and tool life is improved. To harden Zirconia, a high-temperature chamber furnace is required. During this ‘sintering’ process, the Zirconia will shrink by as much as 25% Each Zirconia block and disc is marked with the specific shrinkage factor and this number is entered into the CAM software to ensure accurate final fit. Highly translucent Zirconia requires sintering at a higher temperature, so consideration needs to be taken when selecting a furnace.
The final restorations can be stunning. The digital process provides unparalleled and consistent accuracy, benefiting from a continually growing range of smart materials. Time-saving can be significant, allowing technicians to focus on aesthetics and giving lab owners the freedom to step back from the bench and concentrate on their business. When labs go digital, dentists notice the difference in improved quality, consistent results, faster turnaround, and better customer service.