CAD/CAM Dentistry in a Dental School Curriculum
An update on the impact of technology on dental education
Technology has had a major impact on the practice of dentistry. It has changed the way the dental office communicates with patients, keeps its records, and controls its finances, as well as the way the patient receives treatment.1 Digital technologies now have applications in orthodontics, prosthodontics, and restorative dentistry. In orthodontics, digital impressions guide bracket placement based on virtual planning of tooth movement, and CAD/CAM technology produces customized archwires and plastic aligners.2,3 In implant dentistry, digital scans in combination with CAD/CAM technologies are used to obtain information such as implant diameter, the position of the implant, and the design of the abutment and emergence profile.4,5 In prosthodontics, a recent study has shown the potential for using CAD/CAM technology to fabricate complete dentures.6
Presently, there are many CAD/CAM units from which to choose. There are units that are only capable of taking a digital image and then sending that image to the laboratory for construction of the restoration. There are more and more units coming to the marketplace that can either take the digital image or send it to the laboratory or can make the restoration in the dental office while the patient waits with delivery in a single appointment.
CAD/CAM in Educational Settings
When the University of Tennessee College of Dentistry first became involved with this technology, the only chairside unit available was the CEREC® unit made by Sirona (www.sirona.com). Currently, approximately 15% of the dentists in the United States have a CEREC unit, and there are over 50,000 units worldwide. Seventy-six percent of the dental schools in the United States have at least one and many have 10 units. At least eight dental assisting programs are using them for imaging and design training as more states make it a legal function of the dental assistant. This means that there are more than 500 units in dental education facilities in the United States (Sironal internal data).
Many military bases (Army, Navy, and Air Force), VA hospitals, and public health dental clinics are using this technology to offer same-day dentistry and enhance the quality of care for their patient population. As a result of this technology, these governmental organizations are able to deliver quality intracoronal or extracoronal restorations at a more economical cost in one dental appointment. The ability to reduce the patient’s chairtime by imaging, designing, milling, and delivering a restoration in one appointment is an important service for the special needs of the patient population of these organizations.
Dental School Integration
The University of Tennessee College of Dentistry was one of the first dental schools in the United States to embrace CEREC 3D CAD/CAM technology and integrate it into the undergraduate curriculum. In the fall of 2000, the College of Dentistry had five CEREC 2 units donated by Sirona to evaluate. In 2001, the dental school purchased a CEREC 3 unit and started to incorporate this chairside “Ceramic Reconstruction” technology into the undergraduate curriculum.
It was difficult to incorporate much of this technology into the curriculum with only one unit, so in 2011, the dental school acquired an additional 10 CEREC 3 Redcam units and 10 compact milling units as part of the Sirona Gifting Program to dental school. How this technology was integrated into the curriculum at that time has been reported in previous articles.7,8
In January 2013, the College of Dentistry was able to upgrade the 10 Redcam units to 10 Bluecam units again through the gifting program offered by Sirona Dental Systems. At the same time, an Omnicam, a MC XL Practice Lab milling unit, and an InFire Zirconia oven were also purchased for use in the student clinic. Shortly, an additional 4 Omicam and 10 Bluecam units will be added to the clinic. These new units have greatly increased the capabilities of the students to offer the dental school patients excellent and timely treatment.
Curricular Changes
These new purchases have also required some changes in the curriculum to make use of the technology. Previously, the first-year dental students were introduced to the software as a part of their Dental Morphology course. “Introduction to CAD/CAM Dentistry” is a recently added laboratory course designed for first-year students to apply the technical procedure necessary to fabricate two CAD/CAM-designed restorations. The second-year dental students use the technology as part of their Fixed Prosthodontic Course during the Summer semester. They prepare, design, and mill two all-ceramic crowns (one of which they stain and glaze). During their Esthetic course that starts in the spring, they prepare, design, and mill a MOD onlay for a molar. They then bond these milled restorations during another session in the Esthetic Dentistry preclinical lab.
In 2015, the tooth preparation sequence was changed. Students begin the Fixed Prosthodontics course in July by preparing, designing, and milling two all-ceramic crowns rather than a gold crown. The gold preparation will be moved to later in the course, since it is the same preparation used for a zirconia crown.
When the students get into the clinic during their third and fourth year, they are encouraged to do as many crowns by themselves as possible. A section of the clinic has been set aside specifically for esthetic and CAD/CAM cases (Figure 1). The students must complete two CEREC restorations prior to graduation. For their first 12 crowns, they must make an impression and either send it to the laboratory if it is treatment planned as a porcelain-fused-to-metal, porcelain-fused-to-zirconia, gold, or an anterior crown, or they can do it themselves on stone models with faculty help if it is a porcelain, IPS e.max® CAD (Ivoclar Vivadent, www.ivoclarvivadent.com), or zirconia posterior crowns. It is also possible for them to do implant crowns, either screw retained or with the construction of a custom abutment. After these 12 impressions, they can move to intraoral digital impressions with the Omnicam or Bluecam (Figure 2 and Figure 3).
The number of restorations that have been done in the clinic by the students has increased steadily since the first one was done in 2002. During the 2013-2014 academic year, 182 restorations were done in the undergraduate student clinic using the CEREC equipment.
Additional CEREC units are also available in the AEGD clinic, the Graduate Prosthodontics Clinic, and Faculty Practice. All the residents in these two graduate disciplines have had training and experience using the CAD/CAM technology. Some of the prosthodontic residents have used the CEREC units to do their projects for their Masters’ thesis.
Staying Ahead of the Curve
The application of CAD/CAM technology in dentistry provides an innovative, state-of-the-art dental service to the patients and is also beneficial for general practitioners.9 CAD/CAM systems have been improving and will continue to change the way that dentistry is delivered to the patient. Each individual dentist must determine his/her level of involvement with this technology and have a plan to integrate it into their practice.
The University of Tennessee was fortunate to have past and present deans and department chairs who realized that this is the future and that the students must be exposed to it as part of their education. Without their enthusiastic support, none of this would have been possible. These and many other technology additions at the College of Dentistry have allowed the students to receive one of the most advanced educations in the United States.
Disclosure
James F. Simon, DDS, MEd, received an honorarium from Sirona Dental.
About the Authors
James F. Simon, DDS, MEd
Director, Division of Esthetic Dentistry
Department of Restorative Dentistry
University of Tennessee College of Dentistry
Memphis, Tennessee
Timothy L. Hottel,DDS, MS, MBA
Professor and Dean
Department of Prosthodontics
University of TennesseeC ollege of Dentistry
Memphis, Tennessee
Janet L. Harrison, DDS
Professor and Chair
Department of Restorative Dentistry
University of Tennessee College of Dentistry
Memphis, Tennessee
Mojdeh Dehghan, DDS
Associate Professor
Department of Restorative Dentistry
University of Tennessee College of Dentistry
Memphis, Tennessee
References
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2. Grauer D, Proffit WR. Accuracy in tooth positioning with a fully customized lingual orthodontic appliance. Am J Orthod Dentofacial Orthop. 2011;140(3):433-443.
3. Marcel TJ. Three-dimensional on-screen virtual models. Am J Orthod Dentofacial Orthop. 2001;119(6):666-668.
4. Patel N. Integrating three-dimensional digital technologies for comprehensive implant dentistry. J Am Dent Assoc. 2010;141(suppl 2):S20-S24.
5. Priest G. Virtual-designed and computer-milled implant abutments. J Oral Maxillofac Surg. 2005;63(9 suppl 2):22-32.
6. Goodacre CJ, Garbacea A, Naylor WP, et al. CAD/CAM fabricated complete dentures: concepts and clinical methods of obtaining required morphological data. J Prosthet Dent. 2012;107:34-46.
7. Simon JF, Dehghan M. Technology in a dental school curriculum. Inside Dentistry. 2012;8(3):116-118.
8. Dehghan M, Simon JF, Harrison J. Integrating the CEREC Technology at UT College of Dentistry. J Tenn Dent Assoc. 2012;92(1):19-21.
9. Miyazaki T, Hotta Y. CAD/CAM systems available for the fabrication of crown and bridge restorations. Aust Dent J. 2011;56(suppl 1):97-106.
