3D Printing Technologies in Routine Clinical Dentistry
Improving the delivery and customization of patient care
Jaewon Kim, DDS, MSD, PhD; Amine Benaffane, MS; Praveen R. Arany, BDS, MDS, MMSc, PhD
The ability to provide immediate comprehensive care to improve the oral and general health of patients is a major attraction to pursuing a career in clinical dentistry. Relieving oral-dental pain and improving the esthetics of smiles has a significant psychosociological impact on patients, which results in a great deal of satisfaction for clinicians. In providing that care, the early adoption of materials and technology has always been a key aspect of delivering the best outcomes. The digital revolution in dentistry began decades ago with the adoption of CAD/CAM technologies and subtractive methods (eg, milling) for the fabrication of restorations, and that has led to the incorporation of digital technology into virtually every aspect of dentistry, including impressioning, treatment planning, and recordkeeping.1 Today, the cutting-edge technologies for the fabrication of restorations involve additive methods.
Significant Progress
The first 3D printing technology, the stereolithography (SLA) machine, was patented in 1984 by both US and French inventors. Later, in 1988, the fused filament fabrication (FFF) 3D printer was developed by Stratasys, which was then commercialized and marketed in 1992. These early devices were slow and clumsy, and their low resolution made them incapable of replicating fine design features, such as occlusal anatomy, so they did not receive much attention in dentistry. However, since then, the technology has improved dramatically, and many manufacturers now offer compact, cost-effective, and efficient 3D printers for dental applications. Beyond the availability of affordable devices, much of the rapid progress in this field can be attributed to the online forums of 3D printing hobbyists, which have helped to enable adoption and facilitated the troubleshooting that invariably comes with advancing technology. For clinical dentistry, this has been a major boon because we routinely use a variety of polymers for a broad range of applications, from simple bite blocks and tongue retractors to actual clinical care devices, such as mouthguards, temporary crowns, and prostheses among many others. In fact, the ability to 3D print custom parts on demand has significantly aided in the customization of clinical care as well as in practice building.
Realizing the Benefits
Whether dentists' first experiences with additive 3D printing technology are at scientific meetings, in CE courses, or in other situations, it is difficult to not immediately appreciate the significant utility of this technology. Many oral surgery residents order rather expensive CAD/CAM models from commercial vendors to improve their clinical care; however, they can learn about and quickly adopt 3D printing technologies to create precise anatomical 3D bone models from patients' cone-beam computed tomography (CBCT) scans and digital imaging files. Despite the apparent complexity of the software and hardware, many are awed by the relative ease with which they can generate simple devices using a desktop 3D printer. With ample support from online forums and colleagues, it can be astonishingly easy to quickly master the basics.
The evolution from 2D radiographs to 3D imaging has significantly enhanced dentists' diagnostic and presurgical planning capabilities. Furthermore, their ability to plan and simulate surgery with 3D printed models has greatly increased their confidence and success in surgical procedures, especially for more challenging cases. Multicolor 3D printing technology (eg, Prusa MK3, Prusa Research) has been particularly impactful in generating clinical anatomical models that can aid in presurgical planning, patient education, motivation to accept treatment plans, and improved intraoperative experiences for both clinicians and patients. These models have significantly improved postsurgical evaluations, didactic training, and the documentation of the quality of clinical care.
Although the use of FFF technology provides many benefits, learning the additional workflow for SLA printing opens the door for even more. The improved resolution, better finish of the end products, and availability of FDA-cleared materials to produce devices are significant advantages of this technology. This approach allows us to generate clinical devices, such as surgical guides, temporary splints, and mouthguards, among others, that can be used intraoperatively. Unlike FFF printers, SLA printers have a wide range of resins available for clinical use, which has made adoption of the technology more popular for routine dental applications. A growing list of commercial companies (eg, Formlabs, Carbon®, EnvisionTEC, SprintRay) have enabled superior printing outcomes that are on par with the devices fabricated by dental laboratories. The use of SLA printing to generate implant surgical guides, retainers, and dentures (both partial and complete) has gained much ground recently.
Our own experience with additive 3D printing technologies, both FFF and SLA, has led to the recent publication of research utilizing a combination of these technologies in challenging clinical cases.2,3 These clinical cases demonstrate the feasibility and synergistic utility of several discrete additive 3D printing approaches and their workflows (Figure 1 through Figure 6).
A Bright Future
Despite all of the advances in the utility of 3D printing in dentistry, there are a few remaining challenges in this field that are being actively researched. The speed of 3D printing and the rather cumbersome nature of many of the software programs are clear limitations. Attempts at using multiple, rapid deposition approaches as well as a unified GUI-based interface are key areas of development that could significantly improve the routine adoptability of 3D printing technologies. Although the retail FFF and SLA printers are quite affordable (less than $5,000), many of the commercial 3D SLA printers remain cost-prohibitive ($25,000 to $40,000). Furthermore, uncertainty remains regarding the precise regulatory standards for the resins and the printers themselves. There is significant excitement about the progress of additive 3D printing technologies for metals and ceramics; however, for the moment, these remain cost-prohibitive for routine clinical use and are still relegated to laboratories. On the horizon, the concept of 4D printing with multiple materials is being developed, in which the additive printed object, or its parts, can be functionalized with external stimuli such as heat, humidity, or biophysical forces.
In summary, it appears that despite the perceived complexity of 3D printing technology, its significant utility can have a major impact on our ability to deliver timely clinical care and improved outcomes for patients. The affordability and ease of use of modern 3D printers, which are akin to our paper printers, make their implementation readily feasible, and education regarding their use should be included in routine dental didactics as a major avenue for the customization and individualization of patient care.
References
1. van Noort R. The future of dental devices is digital. Dent Mater. 2012;28(1):3-12.
2. Kim J, Lee DH, Markiewicz MR, et al. Additive 3-dimensional printing as a novel tool for pre- and postsurgical evaluation and patient education: a clinical case series. J Am Dent Assoc. 2021;152(7):567-575.e5.
3. Kim J, Lin YC, Danielak M, et al. Virtual planning and rapid 3D prototyping surgical guide for anterior crown lengthening surgery: a clinical case report. J Prosthodont. 2022;31(4):275-281.
More on 3D Printing
Looking for more articles that demonstrate the applications of 3D printing in restorative and surgical workflows? Browse Inside Dentistry's online library, which includes the following:
Efficient, Predictable Denture Fabrication
Conrad J. Rensburg, ND, NHD
This article presents a workflow to simplify record taking using the existing prosthesis and then deliver a new 3D printed prosthesis fabricated from strong and esthetic polymers.
insidedentistry.net/go/tech2023-R1
Tooth Replacement in the Maxillary Posterior
John R. Francis, DDS, MS
This case report demonstrates the favorable outcome of guided implant placement with a surgical guide fabricated using CBCT data and implant planning software.
insidedentistry.net/go/tech2023-R2
The Race for the Crown
Jason Mazda
Additive manufacturing has become more than just a novelty in dentistry. This article discusses the expanding options for 3D printing permanent restorations.
