The SensAble Dental Lab System provides a comprehensive integrated solution for scanning, design and output to 3D printing for the production of partial frameworks, crowns and bridge substructures. It is based on 3D virtual proprioception. Technicians design and create the prosthetic restoration working entirely digitally, while keeping the manual proprioception to which they are accustomed. One of the unique features of the SensAble System is the PHANTOM Desktop device, an intuitive 3D-interface that allows technicians to use their design wax up skills and to combine these with the advantages of working digitally. The system is easy to learn and to adapt to different design techniques.
Dr. George Freedman:How is the SensAble Dental Lab System different from other dental CAD/CAM Systems?
Chris Pow: The major difference is that the SensAble Dental Lab System has a haptic device, the PHANTOM®, which is used instead of a mouse. The PHANTOM is a force feedback device that provides 3-dimensional proprioception of the digital model during design. It literally pushes back on the hand during the “digital wax” design of the restoration. The SensAble system is the only CAD/CAM system that allows the design of partial frameworks, a common task at most laboratories. The SensAble system enables the technician to use CAD/CAM technology to manufacture lost wax technique full gold crowns and porcelain fused to metal crowns, and of course partial frameworks, a very important factor in the purchase decision.
Freedman: What is the function of the PHANTOM device?
Pow: This device is used by the technician, instead of a computer mouse, to interact with the SensAble design software. It mimics the sense of touch in actually hand-waxing the model. The Phantom has a motorized mechanism that provides force feedback, or resistance. The hand-held stylus offers real-time proprioception in working with the digital model; the model’s different contours, including the margins, can be readily felt. It provides for a better sense of design, and this intuitive function save much bench.
Freedman:When designing with the PHANTOM device will the technician’s hands virtually feel the contours of the restoration?
Andrew Joffe: Yes. The PHANTOM device offers an amazing new experience for the dental technician by combining traditional methods with the latest in technology.
Freedman:Given that this CAD/CAM system includes a force feedback device, what are the advantages of using SensAble’s 3D virtual stylus in the process of designing restorations?
Joffe: The virtual workbench mimics real life in designing restorations. Instead of hand-waxing tools, digital design is utilized. The stylus can actually feel the model, feel the curves, feel the wax. Various parameters, such as making the wax harder or softer, can also be set. The SensAble system also allows numerous preferences to be set for the lab, or even for each dentist that help to speed design with greater consistency. Changing over to the haptic device was not as hard as it sound. After a short learning curve it is very similar to real-time, real-life waxing up.
Freedman:Meaning that the grooves and ridges on surfaces can actually be felt?
Joffe: Absolutely.
Freedman: As if actually working with the physical object?
Joffe: Very similar. Just zoom in on the model, and use the PHANTOM to feel all the detail. For example, an object that is 10mm can be magnified until it is 50mm on screen. See everything clearly without magnification glasses.
Freedman: Can the magnification increase the accuracy and the correct positioning of the margins and contour?
Joffe: Yes.
Freedman: What are the technical steps involved? For example: How is the model scanned?
Joffe: The system has four tightly integrated components: a scanner, a design workstation, a production management console, and a 3D printer. The scanner is a Smart Optics scanner with special SensAble-modified software. It has a rotating base inside with a platform where the model is set. Once the SensAble software is initiated, the platform rotates within the scanner and the system takes digital pictures of the model from various directions. SensAble’s special software combines the multiple digital pictures into an accurate 3D model, on which the laboratory work can begin.
Freedman:How is the restoration designed?
Joffe: The scanned digital file of the 3D model is automatically sent to the design workstation where the digital restoration is designed. The design software has numerous time-saving features that allow the definition of the attributes of clasps, major connectors, mesh patterns, and more. Simply choose the task from the tool palette. The computer buildup is similar to waxing by hand. A comprehensive step-by-step tutorial is available.
Freedman:Once the restoration is designed what happens next?
Pow: After design, the project is saved for fabrication. SensAble’s software optimizes the design for the selected restoration material. Then it is converted into an STL file which is sent to the production management console for 3D printing.
Freedman:How, and on what, is this file printed?
Pow: It is printed in resin with paraffin wax as the support material.
Freedman:Once the pattern is printed, what happens next?
Pow: The various printed parts are cooled and removed from the printer plate. They are cleaned ultra-sonically at a specified temperature to remove the support material. They are then placed on the master models to check for high spots or tight contacts. Then, conventional production with the SDLS printed resin pattern permits casting the pattern in alloy for partial frameworks and crown and bridge cases or pressing crowns and bridges with a pressed ceramic.
Freedman: How is data exported from one part of the system to another?
Pow: The SensAble system is integrated. Everything is on a network, and all the computers can see and talk to each other with SensAble’s case management user interface streamlining the entire process. Files are sent directly from scanner to design station to the printer.
Freedman: Can the SensAble system be used to make various types of restorations, for example flexible or metal partials, bridges, crowns, posts?
Pow: Certainly. The system is multi-purpose: it can manufacture metal and flexible partial frameworks, full contour crowns, PFM substructures, pressed ceramics and combination cases with attachments. The SensAble system can do anything that can be accomplished with the lost wax technique. In our laboratory, we first focused the SensAble system on partial frameworks, and now are using it for crown and bridge applications as well.
Freedman: If the case involves a cast framework supported by several crowns with well defined rest areas, can all the procedures be accomplished at the same time?
Joffe: First spray the crowns on the model with a powder that dulls the metallic surfaces and then simply scan the crowns into the SensAble system. Once the 3D digital model is available, any rest or attachment can be designed
Freedman:What about implant infrastructures?
Joffe: With the SensAble system, the implant abutment is scanned and a restorati
on is designed over the abutment. Whatever is scanned into the system, the resulting 3D digital model can be used as a basis for the digital design with the SensAble software.
Freedman:What level of precision does the SensAble System offer?
Pow: The biggest advantage of the SensAble system is that it allows design right on the master model – particularly the chrome partial frameworks. It eliminates the need for a refractory model, which of course always has the potential for expansion and contraction that may cause errors and distortion. The elimination of the refractory model is a major success factor.
The digital system adds consistency. There are subtle differences in the way each technician works. With SensAble’s system, preferences with specific parameters can be set, including cross-sectional profiles to define specific shapes. Other parameters such as expansion ratios – can be set in the preferences to optimize fabrication processes. This makes tasks highly repeatable; the same profile can be reused repeatedly for similar cases. Compared to traditional hand-waxing, digital procedures are more consistent. Many dentists indicate that SensAble-created parts are the best chrome frameworks that they have ever received.
Freedman: The SensAble Dental Lab System brings a totally new dimension to dental restorations by using the only system that has been developed on the basis of using a 3D virtual touch interface to help design the restoration and give the technician total control over every new step along the way. It keeps the manual dexterity and the sense of touch that dentists and laboratory technicians are accustomed to, while providing the highest level of accuracy to the dental restorative process. oh
Freedman: How has the SensAble System affected your clinical restorative dentistry?
Tabbara: I have observed that every SensAble restoration is much more accurate and better fitting than any other partial that I ever delivered before. Briefly, the fit has been absolutely gorgeous; I have never had to adjust the clasp, tighten, loosen, or anything. The fit is accurate. And it cuts down on chairside delivery time!
Freedman:What advice can you offer fellow practitioners?
Tabbara: The less steps we have the better the results. Additional steps can cumulatively increase problems. The SensAble System eliminates a second model, increasing accuracy and providing a better result.
Freedman: How has your experience been with the restorations done with the SensAble System?
Kaven: The SensAble System has been wonderful. The cases have required probably the least number of adjustments that I have ever experienced. Of the 10 partial denture cases over the past year, every one has fit like a glove,. From my experience, SensAble has been wonderful.
Freedman: What would you say to a colleague who is thinking of using the SensAble system?
Kaven: I would recommend it. While there are some amazingly artistic and skilled laboratory technicians , I still had adjustments here and there. With the SensAble system, though, the lab experience has been wonderful. I would encourage them to use it. I know that Pow Laboratories is planning on expanding the system to crown and bridge procedures. I have seen the SensAble system in the lab. I think its potential is limitless.
