Virtual patients, a reality

March 21, 2012

While advances in technology have dramatically changed the way lab technicians and dentists communicate and work together, and how and who is fabricating restorations, more changes are just around the corner.

While advances in technology have dramatically changed the way lab technicians and dentists communicate and work together, and how and who is fabricating restorations, more changes are just around the corner.

In this issue you’ll find some of the latest product offerings in areas such as 3D intraoral impression scanners, desktop impression/model scanners, CAD/CAM milling systems, 3D printers, and software applications. These technologies have helped labs improve their efficiency and ability to work closely with practices for the best possible end result-great restorations and happy patients.

As these technologies evolve, the industry is getting closer and closer to tying things together to the point where technicians and dentists can work together in real time on a 3D virtual patient. This 3D virtual patient will produce a collaboration that will allow a lab in one part of the country to work closely with a practice in another part of the country, with both parties looking at the same data on their screens and co-diagnosing and co-treatment planning the 3D virtual patient.

Merging Information

Currently, cone beam computed tomography (CBCT) DICOM data doesn’t easily output to STL surface scan data.

“We’re talking about tying together anything that you virtualize, so if you’re going to take the cone beam CT, which is subgingival, and you’re going to take, for example, the 3D intraoral scan or the 3D scan of the actual impression and superimpose all of that together, that gives you your actual 3D virtual patient,” said Eliezer Ganon, Think Tank with Design Technology Gizmo, which is committed to concept-to-market technology developments in the 3D digital and collaboration platforms in dentistry.

“One technology is with the cone beam computed tomography, and the second one is really the optical data. The key with these is to have an actual appliance that will have the actual fiduciary CT and optical markers, so while you’re CT scanning the patient you would have a correlation when you optically scan the patient utilizing a 3D intraoral scanner or desktop impression scanner.”

The cone beam data is based upon bone density, while the optical data is based on light, laser or shapes.

Lee Culp, CDT, and Dental Technologies Inc. Chief Technology Officer, said a number of companies in the industry are working on jelling these two types of data so they can work seamlessly together. The next step after that will be developing affordable software that will then allow 2D images to wrap around CT scans of the skull to deliver a true 3D virtual patient.

“There are several companies that can take STL data and put it into CT data,” Culp said. “But they haven’t figured out how to make it easy enough for the user to do it. You’ve got to send your CT data somewhere and then you’ve got to send your other data somewhere and they’ll put it together. That’s not what the user wants.”

Culp, who previously served as Vice President of Dental Technologies for D4D Technologies, said the makers of the E4D CAD/CAM systems made a breakthrough in this area with its new E4D Compass software that allows users to integrate these two data sets together easily within the E4D software. The next step, which could take 2-3 years, would be optical coherence tomography (OCT) technology which would allow users to see through tissue and capture margins subgingivally. Also, Materialise Dental has accomplished the ability to combine STL and CT data with its SimPlant technology, Culp said.

“That’s huge,” Culp said of the hurdles recently cleared. “Then the third piece that gives us our true 3D virtual patient is software that allows us to take two-dimensional pictures and wrap that around the CT scan of the scan of the skull.

“So right now if you have a CT scan of me, and I know because we did this, you’ve got my face and it basically looks like a big clay model being worked on. Actually there is now software that allows you to take a digital picture of me and basically get the look the same and the lip position the same. You just take that two-dimensional, and it wraps right over that 3D data so now you’ve got somebody’s head on your screen.”

Almost There

Ganon envisions a time soon where collaboration platforms bring technicians, manufacturers and dentists together in a digital realm where intraoral impression scanners, cone beam CT scans and real-time communication allow for this new, high-tech, efficient way of doing things.

“Basically we’re talking about virtualizing the patient on two levels,” he said. “One is virtualizing the patient using the actual computed tomography data, and the second one is to have the patient data 3D virtualized or scanned using optical/laser. For example an optical laser scanner may not pick up based on bone density. It would pick up upon shape, or if you have an actual reference of data to correlate the two you can get your subgingival and your surface data, which is basically your crown and bridge.”

In some regards, we are already there. Culp mentioned the advances with E4D and SimPlant, while partnerships and newer offerings from the likes of 3Shape, Sirona, 3M ESPE and Cadent also are helping make great strides in the areas of CAD/CAM, digital impression taking and greater information sharing between labs and dentists.

“For example, in today’s world of image-guided surgery and orthodontics you need to know where the subgingival is, you need to know where the nerve is, you need to know where the roots are at, and you need to know where you are able to place an implant based upon where the bone or bone density is,” Ganon said.

“From an esthetic point of view, you need to know where your occlusion is going to be, where your subgingival surface terrain data is, and you need to know what the surface data is as well. So you need to be able to correlate the two.”

Ganon has been working with a new device referenced as a Computed Tomography/Optical reference appliance that allows a patient to be scanned subgingivally with fiduciary markers and that optically scans bite registration/full impression. which enables you to superimpose DICOM and Optical Data Sets. “We’re talking about being able to use a cone beam and to be able to use the same appliance that correlates the reference point to be able to correlate that data,” he said. “I’m already using that now.”

Dan McMaster, Marketing Operations Manager, 3M Digital Oral Care Dept., said 3M ESPE has been hard at work providing solutions for these obstacles. He believes the key to making this work is smooth integration between the CT and the intraoral scans.

“Creating the applications that are intuitive, accurate and clinically relevant for these data requires development and testing efforts between the technology providers, as well as smooth collaboration between the oral surgeon and restorative clinician,” McMaster said. “The challenge today is that with only one part of the picture, the case is optimized either for the implant and bone placement, or else restorative function. When both parties have the full picture and can plan treatment in a collaborative fashion, the potential for an optimized procedure that adequately factors in both aspects can be better realized.”

The 3M Lava Network contains both CBCT Technology (3M ILUMAVision) and intraoral scanning technology (3M Lava C.O.S.). “Further, because 3M has experience integrating other components of the Lava Network (connecting intraoral scanners to lab CAD/CAM software platforms, for example), 3M is well-positioned to provide a fully integrated solution in the future,” he said.

What's next?

Ganon likens this future scenario to what is known as the Product Life Management (PLM) in other industries. These updated data sharing capabilities will allow for close detailing of every phase of this virtual patient’s treatment.

“In the world of dentistry, we have multiple disciplines: ceramists, the general practitioner, the periodontist, along with a prosthodontist, oral surgeon and orthodontist. So when you try to manage a case or manage a patient, you have to go through a patient life.

“Call it Patient Life Management. How are you going to manage the patient from orthodontics, as far as planning, on up through placing the implant and then having the proper esthetics and occlusion to deliver functionality?”

With Product Life Management you have different things that have to occur for that product to go out the door. When you have a Patient Life Management you want to know basically that all the parts will ultimately result in the proper esthetic.

Now this can happen

“The digital technology is here. It’s here to stay. It’s really made a large impact in the laboratories,” Ganon said. “If you look at customized abutments and customized bars, they have become the norm. Copings and design has become the norm as far as digital technology. Literally, if you look at the manufacturing point of view, digital dentistry is here and it’s here to stay.”

Culp agrees, saying labs are going to evolve from restoration providers to service providers, and the restoration will just be part of the service.“ The successful labs have always been very strong in diagnosis and treatment planning, but it’s been the same thing,” he said. “It’s photographs, it’s models. You put them on an articulator, you do diagnostic wax-ups, you call the doctor. But now, we’ll have that digital patient, and we can be collaborative in real time in a 3D environment.

“I can be working with you, and we can have our patient on the screen-a three-dimensional head, with teeth, jaws, tissue…we can look at smile lines and things like that and move it around and collaborate together at the same time on the screen. Instead of sending models back and forth, we can actually do it right there on the screen. We can move teeth around, implants around, truly collaborate.”