The future is now: Congress speaker Prof. William C. Scarfe talks Dentistry 4.0

If this isn’t the first time you’ve heard of Professor Scarfe, there would be a good reason for that. His recent presentation ‘Dentistry 4.0: Virtually anything is possible’ was live streamed to a rapt audience last month, and is now available to view on demand via the ADA’s CPD Portal. He’s now getting ready to become a key speaker at next year’s long-awaited FDI World Dental Congress 2023.

Aside from all that, as an oral-maxillofacial radiologist who has been interested in the technological side of dentistry and oral health since as far back as the 1980s, he has played a pivotal role in defining the use of Cone-Beam Computed Tomography (CBCT) and other scanning technology following on from that, on an international scale – although his professional and research interests have also expanded way beyond that into the world of data, robotics, artificial intelligence (AI) and more.

“I was originally brought up in Adelaide and graduated from the School of Dentistry in 1981,” says Prof. Scarfe. “I did a stint in the Royal Australian Air Force, did my Royal Australian College exams, fellowship exams and wanted more education in diagnosis.

“I knew I wanted to be an academic. I enjoyed access to technology, and to things that work in general placement. And that’s been the story of my life for 30 years – access to technology.”


We’ve come so much further, so much faster, in recent years. As nanotechnology, AI and the ‘internet of things’ has progressed, the equipment available to academics on the ‘cutting edge’, such as at the University of Louisville, has become more exciting than ever. “I think all the innovations that I’ve seen in radiography in the last five, even 10 years, were part of trends that I didn’t really understand. I was surfing a wave without looking at the wave,” Prof. Scarfe says. “My colleagues made me step back and say, what we’re really doing is not just cutting edge on a particular technology, but it is practice changing.

“I think Australia is at the forefront of access to technology, too. But like the United States, Europe and anywhere else in the world, it doesn’t mean you’re competent in the use of the technology. Just because you have a Ferrari doesn’t mean you can drive a Ferrari. So my role these days is to educate drivers.”

There is also a continuing need for those in both the academic and industrial spaces of the profession to keep up communication and accessibility of information, in order to advance technology at optimal rate. As an example, one of the components of Prof. Scarfe’s ‘Dentistry 4.0’ presentation is micro machines. These devices can be placed in a patient’s mouth, and lock onto the tooth in order to scan the external part of the tooth, and the tooth is prepared – all from the same machine.

Prof. Scarfe has been working with a company in the United States, but then found out that a colleague had been working with another company from Australia. These two efforts were unknown to each other, but they both responded to a need – “and the need comes from a rural population here in Australia,” says Prof. Scarfe, “but it also comes from standardisation, which is another important aspect of it.”


Herein lies the crux of the data side of dentistry. At first flush, the treatment and standardisation of data could seem a dry topic, but in practice, it becomes clear it is the most exciting part of technological advancement.

As technology has progressed, the academic setting has brought together collaborators of different backgrounds who realised that their separate uses of technology could be put to better use if the results were made more widely accessible, and if the data were standardised so the machines being used could ‘speak’ with each other.

“We partnered in radiology with a prosthodontist,” says Prof. Scarfe. “Our concern was that people are doing facial scans and intraoral scans, and people are putting all this data together and trying to simulate or replicate human dentition. However there’s two problems with that. Firstly, all the data is different; it’s not standard data. The second component is: the resulting imaging is not articulated. It’s all static. So currently, we’re looking at a virtual articulator.

“But above all, I think all these innovations are part of a change that we see with digital technology. Once things are digital, as we’ve seen with phones and computers, it’s all interchangeable. It’s just zeros and ones. It’s the key aspect of this fourth industrial revolution, coined ‘Dentistry 4.0’, but it’s not my term. These technologies were all originally completely separate, but digitisation and standardisation of the data has made them all come together.”

However, in order for this to have happened, researchers like Prof. Scarfe had to overcome the very much profit-driven ‘proprietary tech’ trend. “Machines need to be able to talk to each other. It’s called ‘machine peer to machine peer’, but the key to making that work is this: we have to agree,” says Prof. Scarfe. “Industry is very much driving many of these tech innovations – not researchers or institutions – but the problem with industry is they want you to be locked into their product; yes, the early 2010s were particularly big for that.

“Now, if I buy Machine A and have it talk to Machine B, the only way we can get around that is to move data. So we now we have DICOM [the international Digital Imaging and Communications in Medicine standard to transmit, manage and display medical imaging information]. It solved the problem of the question regarding all of this new data – facial scans, intraoral scans, radiographic scans… How do you put it all together and transport it? Well, we’ve all agreed that we’re going to wrap it or encapsulate it so that we can store it and that’s now the standard. Being involved with that, from a concept to actually see it happen and solve a known problem, was very exciting and very cool.”


“The biggest example of advancing ‘Dentistry 4.0’ with this kind of machine-to-machine communication, I think, is that we can now simulate patients’ faces to do very complex restorative procedures, all digitally, and we don’t even have to see the patient,” says Prof. Scarfe. “That’s where we’re going: the virtual patient, the virtual simulation.

“That very positively impacts the patient’s timeframe. The recording of study models, impressions, all these things are just done quickly, then all the files of complex cases can be shared. Instead of the old way – a referral letter, maybe an email, maybe a follow up? Now it’s all through simulations and it’s utterly visual, which is beautiful to me because that’s who I am – I’m a radiologist.

“So in Louisville, we’re working on generating a virtual patient. Making combined data work in a standardised and streamlined way like this means that prosthodontists and periodontal surgeons can get together to work on a treatment plan without the patient even being there. We don’t have the combined presence of the patient, whereas before, we would get them all in and we would all discuss the options. With this, the options are finalised before we even see the patient.

“And then there’s the question of how to communicate these sometimes very complex things to the patient. We’ve seen that, not only with dentistry, but with our oral surgery colleagues as well, there are different approaches to a surgical procedure. Plastic surgeons will approach a fracture or reconstruction completely differently than oral surgeons. And so now we can actually show them what we want to do, and plan it, providing them with the final result and giving them a simulation because, quite often, it’s the appearance that makes a difference. The articulation, the dentition is obviously the mechanical part. But what is the patient going to look like? Acceptance of procedures and complaints of procedures is often
dependent upon the final appearance as a result.”


Of course, being on the bleeding edge of the technological wave, ‘high risk’ is on the flip side of ‘high reward’. Setting the standards for the profession as a whole means there are tremendous amounts of money involved, and industrial partners are necessarily included in the process. So the age-old question in academic circles applies here more than ever: how much does industry get to put its thumb in the academic space?

“That’s actually an excellent question,” says Prof. Scarfe. “Working with a number of industrial partners, they are really open to input rather than negativity. They love to ask the question: ‘what do you really want this device to do?’

“An example of that would be a basic but huge failing with Cone Beam CT. I’d like a CBCT to take images of the teeth, without artefact from metal or motion – so there’s a big innovative push towards using metal artefact reduction, via a software programme used in medicine, and motion artefact reduction too because, like in a panoramic, patients can move during cone beam.

“The dentists can direct the research, and we’ve asked some pretty basic questions about what CBCT can and can’t do, as well as what we wish it could do. We also articulated that we would love cone beam to be at a [radiation] dose level that’s comparable to panoramics, and that’s where different ‘low dose’ protocols have come about. It’s all been because, to some extent, the market requested it.

“It’s all about trust, and what we can provide to corporations, because they have an enormous stake in this, as well as institutions. Institutions don’t produce products and thus don’t necessarily have to make a profit, but corporations do. There are innovations that they have to feed, such as artificial intelligence which is absolutely huge right now, but the one thing corporations or companies don’t have is access to data. What do dentists have? Access to data.”


So what is the timeframe on Dentistry 4.0? “We’re in it,” says Prof. Scarfe firmly. “Are all the pieces together? No. But are all the pieces there? Yes. So it’s getting those pieces. First, it’s about getting the data; not everyone has an optical scanner, so everyone’s still using impressions or alginate. There must be a transition from an analogue system, and we used to do that by scanning the impression in cone beam to give us a digital input.

“I’m excited about sensor technology, and I think that’s the key. Intraoral sensors are getting much more sensitive, with a larger dynamic range. The sensor will automatically adjust, a bit like a camera automatically adjusting for the light conditions, which is exciting. Certainly we haven’t taught analogue film in 11 years now.

“We’ve been working with CMOS, used to be CCD, detectors for 30 years now. However we’re all racing towards a detector now that is more sensitive and more robust, resisting trauma, bumping, saliva, and that is also higher resolution and a greater latitude. In other words, shades of grey, so I’m aware of incorporation of this new sensor technology into digital systems.

“With that, there’s lots of things you can do. If you’ve got a high enough range, you can change the grayscale and look at dental caries. You can also take more images; if you were to place a sensor in your mouth and leave it there, and you had a system that could take images, slightly offset, then what you’d have is the best View Master in the world. Remember the old View Master [toy] where you’d have two images slightly offset and you could see 2D? Wouldn’t it be great to have that in incredible resolution 3D, for a tooth? There is now technology that is available to do this.

“And not only sensor technology, but cathode rays. We’ve been working with Roentgen’s Cathode Rays since 1895. The x-ray tube produces electrons which bombard a target in a very ineffcient process creating high temperatures. Over time, the tube loses its effectiveness. We try to direct the x-rays towards the patient. Newer technologies are called ‘cold cathode’ or nanotube technology, and this is used now. And it’s very cheap! You can get these things for $100, compared with $700 for a regular tube, so that will provide access to this technology not just to people who can afford it, but maybe to more remote or vulnerable people as well.

“So that’s what keeps me going. It’s not looking at a panoramic; it’s looking at a panoramic that’s been adjusted such that no matter where the head movement is, I get a perfect image every time. Second, the interpretation part. I think dentists want to learn, but they’re unsure what’s a bonafide source of information since there’s an enormous number of people offering options out there. This is what’s fantastic about this information being offered through a professional organisation like the ADA or the American Academy of Oral and Maxillofacial Radiology is, they’re all vetted. We know that individuals who are going to present, are presenting on a firm evidence basis, and they have no vested interest – or if they do, they declare it.”


With the current continuing professional development (CPD) cycle finishing up at the end of this month, the timing was perfect for Prof. Scarfe’s one-hour presentation on ‘Dentistry 4.0: Virtually Anything is Possible’ to live-stream through the ADA CPD Portal, as presented alongside the ADA’s own Clinical Media Advisor Dr Peter Norton. It continues to be available and popular on the ADA’s CPD Portal, allowing ADA members who still need to top up their final CPD numbers at the last minute – or get the jump on next CPD cycle as it begins next month.

Topics covered include: Advanced Robotics; Augmented Reality (AR); Big data / Analytics; Artificial Intelligence (AI); Machine-to-machine communication; Cyber security; Cloud computing; 3D printing; Horizontal and vertical integration; and the Internet of Things.

There is more benefit to be drawn from watching live or live-streamed CPD presentations such as these, than simply making up the hours, points out Prof. Scarfe. It’s also the chance to feedback to leading practitioners, academics or researchers, even to the point of helping to inform and influence their next research or technological advances.

“Definitely, hearing from general dentists, that tells us what is really needed out there,” he says. “Giving presentations pre-COVID, people would quite often come up to me afterwards and say, ‘wouldn’t it be great if we could do this or that?’

“For example, there are numerous artificial intelligence programmes that are independent, but they are subscription based. Once data is generated and sent off, there’s a need for it to be given back to the dentist or to the electronic health record, but it’s not happening. Dentists have told me, ‘This is all very well and good, but it’s sitting out there in the aether and I need it back in my chart. If I’m going to do automatic charting or automatic dental caries, I need it to come back’. So with that feedback on board, there are some very forward- thinking companies who are working on that, and have developed AI arms as part of their electronic health record, as a value-added service. It’s all about feedback from real practitioners.”