The document describes a pilot project to evaluate the viability of using digital design and 3D printing to fabricate CBCT/radiographic templates for dental implant planning. Traditional methods for creating these templates require 4 appointments, whereas the digital method developed takes only 3 appointments. Dental casts and rims were digitized to arrange teeth virtually and design the templates. 3D printed templates were then tested on 15 patients and found to reduce appointments for 12 patients, while 3 patients required minor adjustments. The digital method shows potential to improve efficiency but future development is needed to account for dynamic occlusion.

1. Digital Design of CBCT Templates
Carolyn Kincade, Fari Karimi-Boushehri, Martin Osswald, Suresh Nayar, John Wolfaardt
INTRODUCTION
Digitisation of technical/laboratory dental procedures is gaining momentum. The use of digital technology in a dental laboratory has the potential to increase quality and reproducibility, better meet clinical functional
requirements, and improve aesthetic outcomes for patients. This requires the appropriate software and digital equipment, along with specialized training to keep up with industry standards. Traditional methods continue to be
utilised; these ‘analog’ methods involve the manual manipulation of dental materials, which can be time consuming. Many areas of dentistry are turning to Computer Aided Design and Computer Aided Manufacturing
(CAD/CAM) solutions to improve workflow. The field of removable prosthodontics has been slow to adopt these technologies due to the scope and complexity of the prostheses. For example, the conventional process for
fabricating a complete diagnostic denture as a radiographic scanning template for simulated implant planning involves a minimum of four chair side appointments, requiring the clinician and support staff with additional
laboratory work at each appointment. Patient care and workflow could benefit from utilising digital pathways to improve the process of complete denture fabrication.
OBJECTIVE
The aim of this pilot project was to determine the viability of digitized denture tooth arrangements in the fabrication of Cone Beam Computer Tomography (CBCT)/radiographic templates used for diagnostic purposes and
implant instillation planning, thereby reducing chair side time and patient visits
METHODS
The laboratory at iRSM produced accurate diagnostic prostheses/templates with imbedded radio opaque markers to be used in the acquisition of CBCT scans and subsequent CAD implant installation planning. The laboratory
designed CAD diagnostic prostheses using an optical scanner (ShapeGrabber Inc, Ottawa ON) and CAD software programs(Magics: Materialise Technologielaan, Leuven Belgium) (Freeform and Control: 3D Systems, Circle Rock
Hill, USA) The diagnostic prostheses were then manufactured through a CAM process using additive manufacturing or 3D printing in a material with properties similar to those of acrylic.
The process began with the clinicians providing preliminary alginate impressions of the patients’ current oral environment from which the laboratory fabricated casts and occlusal rims following standard biometrics. The
clinicians utilized the occlusal rims to determine patients’ smile lines, planes of occlusion, condylar positions and to provide the laboratory with a jaw relation recording (JRR) (fig. 1 &2) .
The JRRs were used for mounting the maxillary and mandibular casts. Upon completion of traditional mounting, the laboratory digitized the maxillary and mandibular casts and rims to derive digital relationships of the jaws to
each other (fig. 3). Separate scans of the mandibular casts and rims, maxillary casts and rims, and bite were aligned to each other utilising virtual planning software (Control: 3D Systems, Circle Rock Hill, USA). The digitization
process was completed with the use of an optical laser scanner (ShapeGrabber Inc. , Ottawa ON).Digitized denture teeth, selected by the clinician, were arranged digitally using CAD software (Magics : Materialise
Technologielaan) into the required positions as per clinician direction from the jaw registrations obtained (fig. 4).
Fig. 5
Fig. 1
Fig. 10
REFERENCES
Karkar, I. G., Huafeng, W., & Karkar, P. G. (2010, April 29). System, Method And Apparatus For Tooth Implant Planning And Tooth Implant Kits . Retrieved October 14, 2015, from
https://www.google.com/patents/US20100105011
Lin, W. S., Harris, B. T., Ozdemir, E., & Morton, D. (2013). Maxillary rehabilitation with a CAD/CAM fabricated, long-term interim and anatomic contour definitive prosthesis with a digital workflow: A clinical report. Journal of
Prosthetic Dentistry, 1-7.
Bidra, A. S., Taylor, T. D., & Agar, J. R. (2013). Computer-aided technology for fabricating complete dentures: Systematic review of historical background, current status, and future perspectives. The Journal of Prosthetic
Dentistry, 109(6), 361-366.
Rudolph, H., Luthardt, R. G., & Walter, M. H. (2007). Computer-aided analysis of the influence of digitizing and surfacing on the accuracy in dental CAD/CAM technology. Computers in Biology and Medicine , 37(5), 579-587.
Lin, W. S., Harris, B. T., Ozdemir, E., & Morton, D. (2013). Maxillary rehabilitation with a CAD/CAM fabricated, long-term interim and anatomic contour definitive prosthesis with a digital workflow: A clinical report. Journal of
Prosthetic Dentistry, 1-7.
RESULTS
12 of the fully contoured prostheses did not require any further chair side adjustments and were immediately used for CBCT scanning. Three cases required chair
side modification, which was completed at the same appointment with the printed tooth arrangements as described. The CBCT scans for the modified cases were
obtained at the same visit and did not require additional chair side appointments. All 15 cases benefited from the digital method and required only three
appointments as compared to the conventional method which requires four patient visits.
DISCUSSION
The three cases required additional adjustments due to occlusal factors as the digital method described does not account for dynamic functional movements and
the CAD programs do not have the adjustability/functionality of a dental articulator.
CONCLUSION
The new digital method reduced laboratory time, decreased the number of patient appointments, and has the potential to reduce operating costs. The use of a
digital JRR systems and articulators could alleviate the occlusal errors encountered in this study. Future development of this technique is required to explore the
potential for complete digital denture design and fabrication, further reducing treatment time and costs for patients.
Fig. 11Fig. 8Fig. 6 Fig. 7 Fig. 9
Fig. 2 Fig. 3 Fig. 4
Sculpting of tissue surfaces was performed to achieve traditionally accepted contours and extensions using CAD software (FreeForm : 3D Systems, Circle Rock Hill, USA) (fig. 5-7). The completed maxillary and mandibular
diagnostic prostheses were sent to print. A full contour template was printed for each arch, as well as the isolated tooth arrangement (fig. 8) This separate arch form was to be used if tooth positions required adjustment during
try in. The Standard Tessellation Language (stl) files developed were then sent to a CAM additive manufacturing 3D printer (Objet260 Connex: Stratasys, MN USA).
The printed diagnostic prostheses were cleaned post printing, inspected and verified for patient use. Radio opaque markers were added (fig. 9).The clinicians inserted the printed diagnostic prostheses (fig. 10). Fit, contour and
tooth positioning were verified or modified if required. The CBCT scans were completed and resultant Dicom data loaded into planning software for further simulated digital implant planning (fig. 11). A total of 15 cases were
completed using this method from January 2015 to present.