First Steps to a Digital Workflow
Choose the right CAD model scanner for your laboratory
Audrey Jarrell, CDT, TE
The art and science of dental laboratory technology have experienced a significant paradigm shift, which affects the fabrication process for restorative products. Those who manufacture crowns, bridges, and other fixed dental restorations have witnessed a rapid change in the means by which these restorations are produced over the past 10 years. Previously, the most valuable tool in any dental laboratory may have been casting equipment or porcelain furnaces. Now, the most valued piece of equipment is more likely to be the model scanner. In 1987, the process of scanning in vivo and in vitro dentition was called “dental holography.” Scanners have since evolved greatly and now have the ability to not only capture high levels of accuracy, with reported ranges of 5 to 15 microns (μm), but also complex detail, including textures, colors, and high-definition imaging. For instance, some scanners can capture two models in a single scan cycle without the need to remove individual dies. Furthermore, advances in scanning software provide the ability to integrate peripheral scans such as CBCT radiographic scans, face scans, 2-dimensional pictures, and more, which provide the restorative team with critical information. Due to the incredible rate of technological innovation, it is pivotal for laboratories to stay abreast of new advances, including the scanners that can provide the greatest benefits for their laboratories, patients, and clients alike.
What Scanner Should I Buy?
Before making any large capital equipment expenditure, it is critical to define what the business needs and align those needs with the functionality and capabilities of the more than 30 scanners that are currently on the market. Based upon the laboratory's preferences, it can narrow its search by asking the following basic questions.
Does the scanner architecture offer an open or closed platform? If it is a closed system, what is the fee to open it?
Not all scanners are alike in their technology, accessibility, or output. Scanners that have closed architecture create a propriety data file that is only usable by the manufacturer's system. These closed-architecture systems require that the laboratory technician utilize that manufacturer's proprietary digital process, including scanner, software, and milling machines. Scanners that are able to produce an open-format stereolithography file (.STL file) allow the scan data to be integrated into any open-architecture design software and provide open accessibility to any software, milling/printing machine, and material technology. Still other systems claim to be open, but require a “request and fee” to generate an open scan output file. Understanding these indications is of critical importance for the longevity and viability of a CAD model scanner.
What is the accuracy and speed of the scans?
CAD dental scanners have come a long way with regard to precision and speed. Just a few years ago, 25 μm was considered best-in-class in terms of scanning accuracy. Today, most scanner manufacturers report accuracy ranging from 5 to 15 μm. It is the scanning technology that provides both the accuracy and speed of scans. Each CAD scanner manufacturer has its own proprietary scanning methods, but all dental CAD scanners utilize either blue light LED, white light LED, or laser as a source of light, coupled with either laser triangulation, stripe light, or conoscopic holography.
Different scanner manufacturers claim quite a wide range of reported speeds. These speeds are dependent upon the proprietary software algorithms that stitch together the scan data to create the 3-dimensional rendering of the object. For example, a single die can be scanned in as little as 12 seconds to as long as 1 minute, while a full antagonist arch or an unsectioned arch can be scanned in as little as 12 seconds to as long as 1 minute and 10 seconds. A sectioned model or working model scan has a reported speed range from as fast as 12 seconds to as long as 3 minutes and 30 seconds.
Furthermore, color and texture are important factors that are particularly relevant to laboratories. Entry-level scanners typically scan in black and white, without texture. However, when a higher level of complexity in scanning is required, there are now scanners capable of capturing both color and texture. The laboratory owner or manager responsible for making the purchasing decision should assess the laboratory's needs against the speed capabilities of any scanner or system under consideration.
Why should precision and speed be considered when selecting a scanner that would best integrate into the laboratory's workflow? Scanning speed directly correlates to production and the laboratory's ability to navigate through the digital workflow quickly, accurately, and easily. Assessing the speed of the scanner to attain a 3D rendering is critical. Although the difference in speed between two scanners might only be a few seconds, those cumulative seconds could be substantial over the course of the entire work day, and they could provide the opportunity for the technician to increase productivity within the same allotted time frame. The speed consideration is particularly important for laboratories that handle a large volume of cases each day, allowing more work to be completed in a single day. Conversely, laboratories that concentrate on a substantial volume of implant work may view scanning precision, not speed, as the most critical variable when making a buying decision.
Identifying a CAD model scanner that is best suited for the laboratory's workflow will provide the most advantageous outcome for the investment. For a complete reference resource, see IDT's 2017 Product iNavigator “Shop and Compare Chart,” at insidedentaltech.com/idt1003.
Is the design software intuitive and easy to use?
Performing the actual scan is a very important component of the process, but it is just the first stage of digitizing the workflow. The software that accompanies the model scanner must work intuitively to accommodate the actions of the designers. In fact, software engineers have studied the conventional workflow utilized by dental laboratory technicians and set out to duplicate that workflow in the digital realm. This effort has provided a significantly improved learning curve for seasoned dental technicians, as the flow is intuitive and familiar. Closed-architecture systems have proprietary software that offers many of these benefits to the designer, optimized for each specific system. For laboratories that prefer an open-architecture CAD system, there are three available software options—3Shape, exocad, and Dental Wings.
3Shape's Dental Designer software has been successful in creating a smooth and easy workflow for dental CAD designers. The software's transitions through the different stages is intuitive and simplistic, yet incredibly robust in terms of what can be achieved. exocad CAD software is similarly intuitive and is integrated into many CAD scanners on the market. Dental Wings offers packages of scanners and CAD software. All three offer varying degrees of usability and price points suitable to a variety of laboratory needs, with different packages offered by different resellers.
CAD software is a matter of preference; all are capable of producing similar end results. The primary differentiating factors are the comfort of use and the ease of navigation through the software. CAD software designer preference can be compared to the more commonly recognized consumer preference of Apple vs Microsoft.
Does the software allow for networking additional scan/design stations and what is the annual cost to add design modules to the software?
Whether the dental laboratory is enhancing its digital offerings or transitioning into digital production, understanding how the business can scale the equipment is important. A fixed production laboratory, for example, may opt to add removable or orthodontic applications to its product lineup. In such cases, it is therefore necessary to know in advance that the desired scanner and associated CAD software can support such initiatives. Similarly, as the laboratory grows in production capacity, the ability to add modules and design stations is crucial for expansion, allowing the initial investment in the scanner to become more fruitful.
If a dental laboratory is looking to add multiple design stations, some considerations must be thought of at the onset. For 3Shape users, this would require the purchase of a server to host the CAD software and dongles for added stations, as well as smaller client software packages on the designers' computers. In this way, the software can be authenticated on the server and opened by the individual client designer stations. The number of design stations would need to correspond to the number of purchased users on the dongle. Some laboratories have found hosting the software on the server helpful if they allow CAD designers, managers, or owners to design remotely from home. exocad software can be networked similarly, but every design computer would require a dongle to activate the software. Dental Wings has the software license embedded into its scanners, which means that if more design stations are desired, the laboratory would need to purchase subsequent licenses for each one. This must be communicated with the reseller; otherwise the scanner may be sold as a stand-alone system. Also consider that each additional design station may require an annual update cost, depending on the reseller and contract arrangements.
So many model scanners are available on the market today. Considering the items addressed in this article can help dental professionals evaluate what is most important to their laboratory's purchasing decision, now and in the future. The next steps in researching which scanner to buy are to see the scanners in action by going to dental conferences, to obtain additional information by reading dental laboratory publications, and to consider what more to ask the manufacturer representatives based on what you have seen and read. This should include whether or not the software creator intends to stay active in updating the capabilities of the software to meet the changing needs of the industry; how often regular software updates are released; and the initial and ongoing software costs.
After working with so many scanners and companies over the years, it is the author's opinion that the adage “you get what you pay for” is accurate for this industry. Nonetheless, staying with a system that the laboratory and technicians know and trust will provide the greatest benefits. Use the questions above to help guide your search to see which one is right for your dental laboratory business. Happy scanning.
About the Author
Audrey Jarrell, CDT, TE, is with Expertec Dental Lab in Westland, MI.