This week I glimpsed the future of Endodontics, and it was good.
A few weeks ago David blogged about a technique written up using CBCT, some planning software and a 3D printed stent to aim a drill through teeth looking for the pulp chamber.
As a major consumer of all the above technology, I was jealous of the research team’s ability to play with all the latest gear and take a system devised and used successfully for implant placement to locate root canals inside teeth.
I started thinking of ways that the system could be used clinically, with the drills needed to get through crown and bridgework, but the inaccuracy of the plastic jig was a worry, particularly with placement deviations of up to 6-7mm reported. This would be unacceptable if you are drilling through tooth (I guess not so acceptable if you are drilling in jaw near the ID canal either!).
I was then told of a wonderful piece of 3D camera tech by Chris Emery, also devised for implant placement, which superimposed the position of the drill tip onto a 3D scan so that you could watch the progress of your drill through the jaw, following a predetermined implant drill pathway.
The implications for this in our field could be amazing with finally true Guided Endodontics being possible. After Targeted Endodontics, in which only the canals showing signs of pathology are treated, the next treatment category I created shortly after starting to use CBCT nine years ago was Guided Endodontics, in which I used all of the information provided by the scan to plot a virtual direction through the tooth, towards the anatomy that required treating. This I did in my head, with the scan in front of me as I worked, superimposing what I was looking at on the screen with what I was seeing inside the tooth.
This new technology though surpasses that significantly, providing a screen target that monitors the position of the drill in all three planes as it drills through the tooth towards the root canal.
The potential for this technology is simply awesome. It heralds the dawn of total automation with computer guided robots carrying out endodontic treatment, firstly guiding the drills into the root canals, then using a Morita Dentaport style filing system to prepare the canals to an apex locator zero reading, gauging the torque on the instruments and adjusting the file movements. However, even before I consider giving my seat over to the Robot Endodontist, the tech will provide us with the ability to drill tiny accurate access cavities through teeth without significantly damaging them.
After experiencing a quantum leap in the numbers of endodontic failures caused by root fracture, my own treatment rationales have moved to smaller preparations with higher efficiency cleaning strategies to limit the amount of tooth tissue destruction. There is still though the need to excavate deeply, looking for small sclerosed canals, inevitably requiring significant drilling and a weakening of the tooth structure.
A Guided access would provide pinpoint accuracy in canal location, even heavily sclerosed canals, without significant tooth tissue loss.
The Navident System is being sold by The Dental Imaging Company and I contacted the ever-helpful Rob Pounds to see if we could see the machine in action.
Rob brought the Navident over last week and together with David, we set it up to drill guided holes through one of our 3D printed Academy teeth.
The system is not as simple as one would like, with a number of technical pre-requisites needed to be carried out before even scanning the patient in order to ensure the tooth, handpiece, drill and scan can all be accurately lined up.
Diagnosis and treatment planning in endodontics is done with the benefit of the scan. Using the Navident commits you to a good degree of time and effort producing an accurate guide, moulded to the teeth to hold a radiopaque marker in the mouth during the scan, and later during treatment. All of this has to be carried out before you have even looked at the scan and decided on a treatment plan. I understand this is changing though, as the equipment and technology progressively matures.
Markers for the camera attached to the stent and the base of the handpiece make things appear rather Heath Robinson, and the ability to use it all with a rubber dam, will certainly be a challenge, but the fun really started once it had all been calibrated (quick and simple).
The head-up target kicked in on the Mac display as the drill tip came near to the tooth and gave the operator the ability to line up the drill in all 3 dimensions, before switching it on. You could then watch the drill progress down through the tooth, keeping the cross-hairs tightly lined up and counting down the millimetres to hitting the root canal (or in this case a perforation in the side of the tooth)
Despite the surprising difficulty in doing this, I hit the outer wall at seemingly exactly the predicted position.
Obviously, my result was far better than David's, but there is a steep learning curve and with a bit more practice I reckon we could both get quite good at it.
The kit is more than impressive in what it can do, it is just a little fiddly at the moment.
We are going to do some more experimenting shortly to test how accurate the Navident could be in locating root canals.
Watch this space!
Our grateful thanks to Rob Pounds of the Dental Imaging Company and Navident.