The state of intraoral scanning

August 23, 2017

Article

Exploring the exciting current reality of intraoral scanning, as well as what’s coming in the future.

Early intraoral scanners had some major challenges. They didn’t replace the traditional workflow right away, they came with an intimidating learning curve and they often required the use of multiple other supplies to get a useable scan. It was almost as if the digital dentist and laboratory had one foot in the future and one in the past; one hand operating in the modern workflow and one stuck in tradition.

“Even back in the early days of intraoral scanning, a lot of times the labs would create their restorations using traditional methods,” says Jim Graham, global research and development director at 3M Oral Care. He says that labs would use digital files and 3D print models, but often relied on analog techniques to create final restorations.

Early adopters are always willing to put up with the murk of nascent technology, but to most, it just wasn’t more attractive than performing the skill they’d learned and honed long before.

“Within the clinical setting, you had this traditional impressioning capability that everybody had been taught from day one of dental or hygiene school,” Graham says. “Everybody knew how to use it, so it was simple, quick and effective. Suddenly, you’re asking your clinicians, assistants and hygienists to adopt this new technology that was completely different than anything they had been taught in the past.”

Now, the capabilities of intraoral scanners and the software available outweighs any learning curve. And with the potential of what digital impressions could be in the future, the time to adopt is now. They’ve come a long way in the last few years

“My history of chairside oral scanning started back in 2006,” says Payam Ataii, DMD. “Since then, the quality has improved tenfold, if not more. Scanned images appear instantly with crisp definition.”

In fact, digital impressioning technology has evolved so much that it is “over-delivering” by consistently and quickly acquiring quality data to ensure predictable outcomes, says John Cox, vice president of Technology Sales at Henry Schein.

That’s not to say that using an intraoral scanner is akin to waving a magic wand around the mouth (this mental image courtesy of Justin Chi, DDS, CDT, but more on that later)-but it has seen some major improvements.

“What I bought the first time was really a tooth-by-tooth system,” says David Rice, DDS. With improved accessibility, things have changed. “Now, I can do multiple teeth in a quadrant and work on bridges and dental implants. The range of procedures that we can now work with is almost limitless.” His range also includes working with orthodontics (both traditional appliances and clear aligners) and integrating with 3D cone beam CT scans for airway and sleep apnea cases.

Imaging and color capture

Cameras are getting much better, and many of them can capture images in color, allowing clinicians to see subtle nuances.

“What you see is a 3D image of the clinical situation now,” says John Flucke, DDS. “Nowadays, companies have all made it look like a clinical impression: even the coloring on the screen. It’s just like taking a model and holding it up in front of you with two hands.”

Digital impressions have a huge impact on patients who certainly notice the difference between an impression tray and a digital wand.

“I have an older system and my patients still think that I have some ridiculously high-tech thing,” says Leah Capozzi, DDS. “They can’t believe that they’re looking at their tooth on a screen.”

Digital impressions make it easier to educate patients. By using images that are of the patients’ own mouths, they can better understand the situation of their health and recommended treatment.

“[Intraoral scanners are] just becoming more of a universal tool,” Dr. Rice says. “If we’re just trying to educate rather than create, we can use them now to take intraoral images.”

Dentists are also using digital impressions to create a more complete patient record.

“We use a scanner every day, on every patient because I can use the scan as a diagnostic image,” Dr. Ataii says. “When we had the older scanner, we only used it part-time. Time was a problem because it would take four or five minutes a scan. With the new Element, we can scan every patient in less than two minutes during routine visits.”

Fewer remakes and adjustments

The visibility of the impression has improved as well, meaning dentists can tell if they have a good impression right away. “Clinicians can see their preparation on the screen, magnified greater than they’ve ever seen before,” says Dr. Chi, who worked as a certified dental technician before becoming a dentist and clinical research associate at Glidewell.

“One of the biggest complaints and issues in labs across the world is a lack of tooth preparation reduction,” Dr. Chi says. “If there’s a lack of reduction, then laboratories can’t really fabricate the ideal crown for function, fit and longevity because it compromises the thickness of that final restoration if the dentist didn’t reduce enough.”

Many new digital impressioning systems have provided a solution to that issue in the form of a prep-reduction verification. “They can instantly see how much space they have on the screen,” he says. “It’s great, because if there are any issues with the preparation as far as reduction or retraction - anything that wasn’t done as good as it could be - they can go ahead and make that modification to the tooth right then and there and rescan it.”

That makes a huge difference in time savings in the dental office because not only do digital impressions allow for fewer remakes, they also allow for fewer adjustments, which can shave 10 or 15 minutes off a restorative case.

“If the dentist is able to deliver the restoration soon after the preparation appointment, there’s also less of a risk of the teeth shifting around,” Dr. Chi says. “Though we all like to think we make great temporaries, when we’re moving quickly I don’t think any office is really creating provisionals at the same quality and fit and occlusion that a final restoration should have.”

If a temporary is out of occlusion, there is a risk of teeth shifting, which will require more adjustments when the crown comes in.

“I think digital offers that precision because they can set those values, and each time you get that consistent result,” he says. The bonus is that there is close to no margin for error because you can see everything right away.

Optimized workflow

“Dentists can learn a lot from incorporating digital,” Dr. Chi says. “Pretty much every dentist that I’ve spoken to that has gotten into digital impression systems all say that it’s made them a better dentist because you can see the preparation in a way that you hadn’t been able to see before. As a dental technician also, I know what is required to create that ideal crown as far as the preparation reduction and the retraction. The digital scanner is a great teaching tool for dentists to be able to improve the work that they do.”

“When you’re doing an onlay or crown, you can take a quick scan in the beginning instead of taking pre-op impressions,” Dr. Capozzi says. “If you’re sending to the lab, you can do it electronically while you’re still in the room. You’re not filling out slips and packing boxes and waiting for the mail or for a pickup.”

It also helps that everyone can speak the same language now that the data is digital, says Dr. Gary Severance, chief marketing officer of E4D Technologies.

“By capturing that information and having specialists be able to look at it immediately if you need consults or being able to share the information with dental laboratories or specialists, you just get a bigger community of people talking the same language,” he says. “There is much more communication when you all speak the same digital language. You can do consults much quicker, you can send the information over, and dental professionals-technicians, specialists, clinicians, or even team members-are able to see things they were never able to see before without so much redundancy because they’re all looking at the same file.”

He adds that by keeping the data in the cloud instead of in storage, clinicians can learn more about their patients and improve treatment overall.

Short-term tweaks

The short-term goal of digital impressions is like that of other digital technologies: to increase efficiency and productivity. Companies will be working on little tweaks for their latest versions as they bide their time waiting for researchers and scientists to develop industry-changing technologies and materials that will redefine what is possible in the dental office. In the short-term future, we’re going to see those tweaks: higher resolution imaging, increased speed and accuracy, smaller wands, ease of use and more affordability. But those tweaks can only go so far.

“There is going to be a limit in how small they can get and how fast they can get,” Dr. Severance says. “There is a critical balance between the size of the capture and the speed. You can make it very small, but you can’t capture a large amount of data quickly. As electronics improve, we’ll probably be able to capture and transfer more data. One company has gone wireless. Other companies are focused on USB 3.0 and some of the other ports that now allow more power and more transfer of data quickly. They’ll continue to improve as the technology and electronics improve.”

Higher resolution

When it comes to resolution, Cox says there is a point where good enough is good enough. If the naked eye can’t see as well as the camera, where is the value?

“The technology has to accommodate the specific workflow of the dental practice,” he says. “If it gets too far advanced where it doesn’t provide a clinical benefit and challenges the hardware requirements of an office, then it’s exceeding the ROI. We have a lot of practices that have to upgrade some of the hardware because of the graphic requirements of digital impressions. A full-arch scan is a big file; you need computer processing power that will handle it.”

Companies will continue working on the resolution, not because of what is needed today, but what will be necessary tomorrow.

“You’re starting to see a couple platforms that are enabling time lapse or change comparison over time, so an improvement in resolution of the scans will help enable that type of technology to move forward,” Graham says.

More on intraoral scanning: Streamlining the workflow with CAD/CAM dentistry

Faster scans

As with resolution, scans are about as fast as they need to be.

“The staff can’t keep up and scan much faster than the scanners go today,” Cox says.

However, Dr. Flucke foresees a greater efficiency rather than increased speed. “I can envision the camera becoming much more miniaturized,” he says. “Maybe it has several camera heads in it so you can just drag it along the arch, taking pictures from all sides simultaneously.”

Current intraoral scanners are fast. They’re also accurate. But they aren’t always both at the same time-yet.

“I think you’re going to see faster scan times while maintaining accuracy,” Dr. Adam Hodges, DDS says. “In order to be an effective scanner, it has to get quality data in an effective amount of time.”

Ease of use

Ease of use is one tweak that will bring real value to the dentist.

“I think the biggest area of improvement in quality that we’re seeing is in the software that’s driving the scanners themselves,” Graham says. “We’re almost to the point where you can pick up a scanner and learn how to use it without requiring a trainer to come in and teach you.”

He says scanners will get to the point of being able to detect what the dentist is doing and where they are in the mouth while acting as a guide through the process. That will give dentists the option to pass that task on to someone else in the office so that they can focus on procedures that only they can do.

Technique: How to use an intraoral digital impression scanner for restorative dentistry

Automation

Soon that automation will expand into treatment protocol.

“Everybody is working on some artificial intelligence that doesn’t require the user to make the decisions because the computer can learn from previous [cases],” Dr. Severance says. “For instance, the computer can diagnose caries and the software can automatically go to the next step and start preparing for that restoration.”

“Where we’re going with software is to eliminate steps: Tasks that are done routinely every day by a team member will become automated,” Cox says. “With an automated process, we can take the image and it automatically captures the information, attaches it to the patient file and submits it to the insurance.”

That will apply to design as well.

“As the software becomes more sophisticated, it’s going to enable the doctor to have a dialogue with the patient about their oral condition and be able to simulate what effect or change the doctor might be recommending,” Graham says. “Patients will be able to see what their teeth might look like after aligner therapy. You’re going to see more of these capabilities applied to restorative work and smile outcome simulators, even on the scanners themselves.”

“I think in the future it’s going to be like a virtual patient-prior to the dentist meeting the patient, they can gather all the information they need and have a much better idea of what process they’ll want to continue with the patient, without having met them,” Dr. Severance says.

Affordability

At the moment, many dentists fail to see value in investing in an intraoral scanner. Dr. Chi hopes that will change.

“I think that is a big barrier with digital scanners,” he says. “As business owners, dentists certainly need to make the best business decisions.”

“We’ll probably see more systems that allow us to take it from start to finish in the future, and hopefully pricing will shift to bring more dental practices to the table,” Dr. Rice says.

Dr. Hodges thinks a shift toward more affordable systems is likely, as materials and equipment improve, costs decrease and they experience a greater adoption by dentists.

“The next big leap forward would be a system that is affordable and offers materials for virtually any indication,” Dr. Chi says. “Right now, the complete CAD/CAM systems are very expensive and can be very difficult to learn. [Glidewell wants] to offer a system to that 80 percent that just does the bread-and-butter cases in a package that is easy to learn how to scan and design and mill, without the need to finish, stain and glaze and use an oven and all that. I think that would be a big shift for most dentists’ practices.”

Doing more with the data

Dr. Ataii and his peers agree that the quality is good now. “What we have to work on as dental practitioners is the digital workflow,” he says. “We have to get into the mentality that we scan all patients all the time and add to our dental armamentarium.” Having digital impressions on hand will better position dentists when future advancements are made and the software is able to do more with the data.

“As the digital impression will capture information, it’s the software application that will do more with it,” Cox says. “It will look at the data differently than the dental professional can today. As we take images each time the patient comes in, smart software will evaluate that and identify change such as tooth movement, tooth wear, caries detection and tooth fracture.”

“The nice thing about a digital impression is that you can take one today and one five years from now and software is going to be able to tell you what changed,” Dr. Hodges says. “The scanner can add credible, objective data, which is a lot more comforting for both patient and dentist.”

In anticipation of that, many dentists have already started banking data. “It’s a new innovation that people haven’t really talked about,” Dr. Severance says.

“If we all had an open format and saved it, you would be assured of your record. Right now, many of the companies have proprietary formats that don’t allow them to be universally read. As they go open and we have the software to be able to scan the full arch and compare that data over time, it’s going to take time for people to start storing those records and bringing them in.”

“Our strategy is to connect the technologies to make the work efficient within the clinical workflow,” Cox says. “Whatever step it’s replacing or automating, it’s efficient in that workflow and interacts with the patient record. If it doesn’t connect and work within that workflow, it stands alone in the corner of its own database and it’s not efficient.”

Expanding functionality

Long-term goals are more clinical: to aid in diagnostics and to add more manufacturing possibilities.

“When you look at what’s in an intraoral camera and what’s in a digital impression, one fact is very similar: They’re handpiece-type devices,” Cox says. “As devices get smaller, clinicians can do more. Impression scanners will have more functionality in the future: things like transillumination, caries detection and oral cancer screenings.”

Sub-surface imaging and OTC

“I think a great tool that could be added to scanning is the ability to see through gingival tissue,” Dr. Chi says. “If it could see directly through tissue and identify where the hard tissue-the margins of the actual tooth-is, without the need to retract, that would be a great addition to digital impressions.”

“Dentistry is maximizing the use of some of the technology used in other fields,” Dr. Severance says. “Rather than just capturing a snapshot, future scanners are going to capture depth and be able to see through tissue. That’s what’s exciting in the not-too-distant future.”

That technology is called optical coherence tomography.

“I’m really excited about non-radiating imaging devices that can see subsurface,” Graham says. “All sorts of different indications and diagnostics can be possible with subsurface information.”

He argues that an area for improvement would be for devices to offer non-radiating sub-surface imaging and integrate the data into a cone beam CT scan.

Of course, it would also be helpful for tooth prep.

“It would be nice to use the machine to penetrate through the tissue to see the margin without having to uncover it with a laser or a retraction cord,” Dr. Flucke says.

Materials’ impact on chairside

“Any advancements in the chairside solution are interdependent on material sciences, computing and imaging technology as well as optimization of milling strategies,” says Dave Carballeyra, CEREC product marketing manager at Dentsply Sirona. “Small advancements in each of these segments may create a large impact on the overall solution.”

“Many dentists have adopted chairside milling for the big benefit of being able to deliver that same-visit restoration to the patient,” Cox says. In the future, they’ll be able to provide so much more, once crown design is automated.

“There’s a lot of automation in tooth design in the software, but I think it will get much better,” Cox says. “The software will look at the opposing occlusion and the entire dental health in that patient and then it will design the ideal crown, based on all the parameters in a database that’s deep and extensive.”

While generating an esthetic single anterior restoration is a work of art performed by a dental technician today, it could be a product of an automated process in the future.

“Having said that, the lab will continue to be the main source for esthetic anterior full mouth restorations where technicians can tend to it much more efficiently than a chairside,” he says. “Chairside today is used predominantly for single-tooth restorations: inlays, onlays, sometimes veneers. But those more challenging anterior esthetics and/or full mouth cases tend to be done in partnership with a laboratory. Still digital, but in partnership with a laboratory.”

“Once we get to a point where there’s better software to automate that design work, that’s when I see the tipping point to be more chairside milling,” Graham says. “3D printing is going to take off significantly faster once we get materials developed that can provide different indications in vivo for different applications, whether it’s retention or aligner therapy.”

For dentists who are thinking about implementing chairside milling, Dr. Chi advises to start with an intraoral scanner so that they can get accustomed to the workflow and see the results from the digital impression themselves.

“I think it’s a great technology, but there is a technical aspect to it that dentists aren’t really used to,” he says. “The software we use is very simple, but they still have to have an understanding of how to create the occlusion, and once it mills out, if they want to characterize or polish the restoration. Once they learn that, it’s pretty straightforward.”

The next big leaps

Although Dr. Hodges agrees that chairside milling has its place in the dental practice, he believes that the trend is moving away from chairside milling and toward 3D printing instead.

“At one time in dentistry, we believed that where we were going to go from the digital impression is to milling and doing everything in our office and eliminating the lab,” he says. “Now it seems like we’re not necessarily heading in that direction, but digital impressions are gaining a lot of momentum and emphasis. People want that digital impression because the digital data can be utilized within CBCTs to make surgical guides or nightguards. And now they’re making dentures and partials and even in-office printing of models. So the challenge with just having a digital impression and not regular impression materials is what are you going to do for day-to-day study models?”

He says that the affordability of 3D printing is allowing more dentists to print highly accurate models in their offices.

“What people are paying attention to right now is 3D printing,” he says. “They know that if someone can release products that can be used in the mouth, that’s going to quickly drive things toward 3D printing. If a company can produce quality printed Class II materials in an efficient manner, that will be a game-changer in dentistry and be a catalyst for further innovation.”

“Capturing a high-resolution color image of the patient’s tooth or the arch and using it as the actual tooth chart is probably the next big leap,” Cox says. “Think of the power of that in regards to patient education and helping the patient understand what needs to be done so that they can take an active role and accept the treatment.”

When will impression material be obsolete?

“The hold-up is the dentist,” Dr. Rice says. “Like all people, change is hard for dentists. We are our own rate-limiting step at this stage of the game.”

“I’ll probably never throw all of my impression material out,” Dr. Capozzi says. “I would still have it just in case we fry the computer or lose power because you never know. But I would love to not have to take impressions. I think it’s an amazing tool for patients to do the intraoral scan-to not use impression material and to have that instant result right up on the screen.”

And Carbelleyra, at least, believes that digital impressions just aren’t yet up to the task of fully replacing traditional impressions.

“With current intraoral scanning technology in the market today, scanning edentulous arches exposes a limitation,” Carbelleyra says. “When scanning edentulous areas, the software may not accurately position the surface due to the similarity among the topography of the ridge. There are certainly ways to overcome these obstacles, but they are not practical or consistent.”