Another possibility is to maintain a library of tooth micro-CT scans that feature different and controlled levels of complexity in internal anatomy and/or any variation of root size and formation. In this case, students or instructors may order printed model incisor teeth that contain one or multiple canals, mandibular molars with four to five canals, premolars with three roots, etc. Endodontic courses can now be conducted under controlled or desired levels of difficulty to help course attendees advance together as a group in gaining new skills, experience, and confidence.
Yet another benefit of creating model teeth from actual scans is that 3D printers can be programmed to adjust proportionality of sizing and partial sectional views in printed models. This also presents a new possibility for improving patient education. Several firms already provide a wide variety of dental models for patient education, demonstration, specialized dental procedure training techniques, and other applications. 3D printing may help these firms build upon their existing product lines and distribution networks with 3D printed models. Informational value of printed models may actually expand patient awareness for better understanding and appreciation for the benefits of suggested dental procedures. Figure 11 depicts a 3D computer scan image of half a tooth for 3D printing in a sectional view to depict pulpal areas. Physical models of a tooth in cross section, when properly used, provide patients with a tool to better visualize disease and treatment for better understanding and care acceptance. With 3D printing, a tooth scan file can now be printed at 200% (Figure 12) or greater of actual size and with special variations in printed patterns of material layers (Figure 13). Larger models can help staff and dentists better explain care procedures for informed consent. Similarly, a scan file printed at 90% of actual size can introduce an intentional challenge when practicing instrumentation at the bench. This can lead to the learning of new skills and methods for matching these challenges.
Making Printed Tooth Models Available
Once a desired micro-CT scan is chosen, dentists, students, and dental schools may have the scan data file sent electronically to a commercial 3D printing service (also referred to as a “rapid prototyping service” or “service bureau”) equipped with high-capacity industrial 3D printers for hire. These service firms are increasing in number throughout the United States and some operate on a 24-hour basis and/or have capabilities to produce model teeth on short notice within a few hours of receiving scans electronically.
Production of model teeth appears to be cost effective, and price discounts may be offered in quantity orders. As of November 2015, costs for producing four life-size printed molar models from the micro-CT scan shown in this article are approximately $20.00 each excluding any shipping and applicable taxes.
As mentioned earlier, dental laboratories are increasingly adopting 3D printing technologies, and many may already have suitable 3D printers in-house that create digital casts. Since this equipment is already in regular use, technicians may also be capable of printing model teeth in a timely manner that is cost effective.
The usefulness and contribution of 3D printing has yet to be fully realized in dentistry and especially in endodontics. Furthermore, as computer software advances in dental laboratory technology, it is only reasonable to assume that there will be an ability to modify or even create variations in micro-CT tooth scans for adding levels of desired complexity and/or conditions such as to imitate pulp stones, internal/external resorption, dens-in-dente, and more. This may possibly be done by integrating micro-CT scan data with CAD/CAM software for designing digital alterations into the scan. Hence, 3D printing may soon help create new and almost limitless variations of model teeth to help both clinicians and students learn, improve, and advance in the science and art of endodontics.
Gregory S. Jacob, DDS, has no relevant conflicts of interest to disclose.
Micro-CT scans of molar using SkyScan 1172 Micro-CT System are provided courtesy of Raj Manoharan, Micro Photonics Inc., Allentown, Pennsylvania. CTvox and DataViewer freeware programs provided courtesy of Micro Photonics Inc., Allentown, Pennsylvania. MiniMagics viewer freeware by Materialise, Plymouth, Michigan.