At the Academy we are very fortunate to be able to work with small volume CBCT scanning. Second only to the operating microscope CBCT has had the greatest impact on the way in which I practice. Seemingly, current trends are shifting towards the use of CBCT in many areas of dentistry. The three-dimensional revolution will undoubtedly alter the way in which we all practice. We are not far from the time that rubbish dumps will be filled with forlorn panoramic machines looking enviously at the shiny new scanners that have taken their place. The advancement of technology will drive the creation of original and novel treatments that make use of the additional information that the scans provide. I came across this innovative technique in October’s International Endodontic Journal (spoiler alert!) that I would like to share with you (http://onlinelibrary.wiley.com/doi/10.1111/iej.12544/full). A Swiss group working out of the University of Basel have combined CBCT technology with digital scanning and 3-D printing (other rapidly expanding fields) to design custom templates for cutting access cavities in severely calcified incisors.
A common sequel to dental trauma is pulp canal obliteration. Invariably the pulp reacts with calcification of the pulp chamber and canal which occurs from the crown down towards the apex. Oftentimes the residual pulp tissue will become necrotic or contaminated with ensuing periapical disease. The major challenge for endodontic treatment in these cases is accessing the residual apical canal space to clean and disinfect it. Currently this best achieved by using high magnification and illumination to detect the areas of tertiary dentine and by keeping centred in the tooth. This kind of treatment is not for the faint of heart.
The article details an ingenious method whereby a CBCT scan is combined with a digital impression surface scan. By overlaying the two images the authors were able to superimpose a virtual bur (based on commercially available implant burs) placed down the long axis of the tooth. The dimensions of the bur were chosen so that a minimal access cavity can be cut to the depth at which the canal space becomes patent. A stent was then produced via 3-D printing and placed over the adjacent teeth. The stent provides the correct alignment, orientation and depth for the bur to work at in order to access the residual apical canal space. Fool proof, perhaps?
Through guided endodontics a treatment that under routine operative conditions would be at best challenging now becomes far more predictable. The risks of excessive tooth removal and root perforation are greatly reduced and the chance of a successful outcome is enhanced. I suppose that this kind of technique could be used for cutting an access cavity on any tooth? A truly minimally invasive approach by removing just the right amount of tooth structure to allow adequate access to the canals and not a micron more! Another interesting application that comes to mind is the use of a 3-D printed stent in endodontic surgery for cutting bony windows where, the cortical bone has yet to be eroded thus allowing easy access to the lesion and root end.
We are practicing at an exciting time. The juxtaposition of several novel technologies is facilitating innovation in dentistry. I believe that these innovations will provide better, more predictable treatments that will improve the outcomes for our patients. If nothing else they will be great to play with!