There's an established market for outsourcing the 3D printing of surgical guides but Dr Rick Ferguson is on a mission to help dentists print their own guides.
Most of us will need a dental implant, usually a single tooth or a crown, at least once in our life. It's a fairly routine procedure for most dentists, but one that still needs a degree of skill. Most dentists place the implants freehand but using a surgical guide that’s exactly matched to the individual patient can take the guesswork out of the operation.
Dr Rick Ferguson, a practicing dentist who trained at the University of Miami, says that with a surgical guide you can place the implant to within 1mm of where you want it. He adds: “It would take me an hour to place an implant without a surgical guide but now it takes me ten minutes because I don't have to guess.”
He estimates that only two to three percent of implants done in private practice in the US make use of surgical guides. The main reason that surgical guides are not more widely used is down to the time and cost. Typically the 3D printers needed for this sort of work have been expensive and so it’s the sort of service offered by a lab. This in turn means that there can be a delay of several weeks from the time the dentist first sees a patient and orders the surgical guide, to that guide being delivered. Ferguson says that dental patients are extremely price sensitive, noting: “You are looking at about $350 which if you are charging $1200 for an implant is a significant cost and it's not a cost that can be passed down to the patient.”
The desktop solution
Ferguson believes that desktop 3D printers have now advanced to the point that a dentist could make their own surgical guides, and could do the whole process in a day. He has been using an off the shelf printer from Robox that he has tweaked himself. He says that the Robox printer is cheap enough to be an attractive option for a small dental practice, explaining: “The cheapest SLA printer for dentistry is about $25000 and also $100 in material costs to print the guide each time. But the Robox is $1500 for the unit and less than a dollar to print the guide.”
The first step is to take a CT scan of the patient, which is then used to plan the case and to tailor the guide to that patient. For more complex cases the scan can also be used to print a model of the patient’s skull to help the dentist practice the surgery.
Ferguson explains: “So we can work on a case for about 30 minutes in the software. We are using the highest setting to get the best resolution and highest accuracy so that takes about two hours of printing time with the Robox. A full arch guide takes about 3-4 hours and that's about the same for most SLA printers.” But unlike stereolithography, there are no liquid chemicals to deal with so that once the guide has been printed the supports can be popped off. Ferguson adds a metal sleeve to guide the drill bit and then it’s ready to be used.
A self-confessed geek, Ferguson has been experimenting with 3D printers for some years. He says: “I have several 3D printers but the Robox is my favourite for this work. The main thing that drew me to it was the auto calibration and auto bed levelling. I don't see there's any other 3D printer out there that a dentist could use because of the ease of use factor. There's a lot of manual calibration that needs to be done, a lot of manual set up. The second thing was the fact that the print cartridge comes with a chip built in that tells the Robox printer what material and settings. It has to be quick and efficient with the least number of steps as possible. I think that for the 3D printing of surgical guides this is the ideal 3D printer.”
The Robox printer has two nozzles - one large and one small. It can be set up with one or two filaments, with different materials used to distinguish between different parts. It can also take filaments from other vendors, regardless of whether or not they use a chip.
Ferguson uses Blue Sky Plan software, which was developed by Blue Sky Bio. It’s a complete package, specifically designed for producing dental surgical guides with no other software needed. Ferguson explains: “It's really the only one out there that gives the dentist the control of outputting the file to a 3D printer themselves.” The software is free to use but the output to the 3D printer costs about $15 each time.
Ferguson has experimented with different materials but is now using a material from nGen. He says: “I'm glad I used it because I think it prints cleaner and it prints at a lower temperature and it’s a lower cost.” The material is FDA approved, though Ferguson explains that the FDA does not actually certify materials as medical grade but adds: “These are classed as class 1 medical devices because they are going to be used in the mouth for less than one hour so it’s in the same category as dental floss.” It also has a similar approval from the EU. Once printed, the parts are cold-sterilised for safety.
Ferguson, along with his wife Katherine who is also a dentist, runs a small private dental practice. They have also set up an education center - Implant Educators - to help dentists keep abreast of all the new technology. In recent years Ferguson has concentrated on 3D printing solutions. He says: “So our main goal is to educate dentists to use the latest tools to give patients the most accurate result which is why we have decided to do our teaching on surgical guides.”
They work with the university of Florida, which provides facilities and course credits. He explains: “We can bring dentists from any state in the USA to the university of Florida facility and they get to do their own implants with real patients which is the ultimate in training.”
It also neatly makes the point that this is not just a theory but part of Ferguson's own dental practice, which he has honed over several years. But the best part is that this relatively cheap and simple process should make life easier for the dentist, and make a trip to the dentist a little less scary for the rest of us.