3D printing in dentistry: Resins and applications

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The ability to ask a computer to replicate items has long been a staple of science fiction. And, like many of the oldest science fiction ideas – think holograms and video calls – the concept has been steadily moving closer to science fact. 3D printing, once a fantasy, then a niche hobby, is now state-of-the-art, and with the ongoing development of new materials, its applications continue to expand. From nightguards and bonding trays to permanent crowns and denture teeth, 3D printers today are changing the way dental practices deliver care by making essential items accessible, affordable, and, most especially, on the spot.

From prototype to permanent

The history of 3D printing is short, but the technology has evolved rapidly since its invention in the early 1980s. Originally conceived as a method of quickly producing plastic prototype parts for use in the automotive and aerospace industries, 3D printing was quickly recognized for its potential to create models in the healthcare setting. While computer-aided design (CAD) limitations – particularly obtaining data – were chief among the early problems to be overcome in dental applications, the development of laser intraoral scanners in the 2000s eliminated this hurdle, opening the door to myriad possibilities.

Early 3D printers were slow and bulky, confined to laboratories, and the first printing materials were suitable only for extraoral use in dental models and casting patterns. However, as the equipment has become smaller, faster, more precise and more affordable, the focus has shifted to its in-office potential. From model and casting resins, biocompatible materials are taking center stage, leading to an ever-wider array of restorative and therapeutic options. Most recently, Food and Drug Administration-approved polishable, microfilled hybrid resins that can be used to make permanent indirect restorations and full dentures have entered the market, greatly reducing turnaround time and manufacturing costs for these ubiquitous items. Today’s 3D printers can take a scan of a patient’s dentition and produce anything from a model to a nightguard to a crown in a matter of minutes, not weeks, and at a materials cost of just a few dollars each, saving patients and dentists alike time and money.

Dental 3D printers and productivity

Printing resins are compatible with several printer models from various manufacturers, but some companies in the 3D printing market produce both printers and materials that are perfectly matched for use with each other. For example, SprintRay’s Pro S DLP printers and extensive line of print materials work together to provide ultra-precise individual restorations as well as fast, accurate, high-throughput items such as aligner models.

SprintRay Pro95 S 3D printer has a large build platform, making it ideal for all types of models, dentures, surgical guides, occlusal guards, and more. Using SprintRay Die and Model 2 resin, the SprintRay Pro95 S can print up to 8 full-arch, high-contrast models in 15 minutes and up to 22 models in less than an hour at a cost of less than $2 per model. Comfortable, long-lasting, flavorless nightguards printed with FDA-cleared NightGuard Flex can be produced in less than an hour and for roughly $3 each, helping make them more accessible to patients.

SprintRay’s OnX nanoceramic hybrid resin is the first radiopaque restorative 3D printing resin. With translucency and opacity that mimic natural dentition, it is designed for the production of denture teeth to be used in a final hybrid denture. This material, along with other restorative resins such as SprintRay Crown, is ideal for use with the Pro55 S 3D printer, which has a minimum feature size of 55 microns for maximum esthetics and precision.

Dentsply Sirona’s Primeprint, with its highly automated, end-to-end, medical grade 3D printing system, provides practices and labs with the opportunity to improve the patient experience and offer additional procedures and services. Powered by DS Core, Primeprint easily integrates into already existing digital workflows. Dental intelligence hardware and software print biocompatible applications that are both reproducible and accurate. Throughout the manufacturing process, intelligent material handling ensures safe, clean use with RFID coding, which helps reduce handling times, allows for delegation, and enables a high level of productivity. Although integrated with both CEREC and inLab software, Dentsply Sirona’s open, collaborative, cloud-based system also allows dentists to request highquality CAD files from experienced lab technicians through DS Core Create. These files are ready for 3D printing with Primeprint.

The complete Primeprint solution includes the Primeprint 3D printer; Primeprint PPU to wash, dry, and light cure printed objects; and inLab CAD and CAM software 22 to design and adjust printing parameters printing. In addition, you receive the Primeprint Box system to ensure a clean and safe application without direct contact to the resin and washing containers for use with the PPU for pre and final wash. Primeprint offers a variety of validated materials for processing safety of different applications, including splint, model, surgical guide and temporaries. Each material type has associated RFID tagging to detect material levels, intelligent material management for contactless handling, and exact lifetime tracking to ensure timely maintenance.

3D printing resins and applications for dentistry

Of course, matching the material properties to the desired product is essential. Manufacturers of printing resins now offer complete ranges of materials specific to different products, including aligners, wax-ups and denture try-in models; surgical guides, splints and nightguards; bonding and impression trays; and temporary or definitive crowns.

VOCO’s V-Print line, for example, encompasses resins optimized for producing trays, surgical guides, splints, and prosthetic try-ins, as well as casting patterns and different types of models. The qualities of each material reflect the specific needs of the dental office for the items being produced: V-Print tray is printable in greater layer thicknesses for speed, while V-print splint is formulated for high precision, is biocompatible, and has a neutral flavor to promote patient compliance.

V-Print model is deformation- and scratch-resistant and can be precisely ground, while V-Print model fast prints in high layer thicknesses and can withstand the heat of the vacuum molding process used in aligner production. Similarly, the KeyPrint product line from Keystone includes a range of biocompatible and laboratory materials designed for a variety of uses. In addition to resins for creating try-in dentures, orthodontic bonding trays, surgical guides, and gingival masks, KeyPrint comes in three high-accuracy model formulations for restorative and diagnostic, orthodontic, and fast printing applications.

In addition, Keystone has two splint resin offerings: KeySplint Hard and Soft. The rigidity of KeySplint Hard allows the design of thinner, more complex devices that are ideal in cases requiring tooth immobilization, and it is highly wear- and abrasion-resistant, even in patients with severe bruxism. KeySplint Soft changes flexural modulus at body temperature, making it ideal for more comfortable nightguards that resist becoming brittle with age.

Completing the digital workflow

Milling machines already have brought the production of indirect restorations out of the laboratory and into the dental office, but their use is necessarily limited to rigid, millable materials. The ability of 3D printers to create more adaptable items with less material wastage is filling a gap in the chairside CAD/CAM workflow process. And if they don’t yet respond to voice commands … well, who knows what comes next?

Selected references and further reading:

Birnbaum N, Aaronson HB, Stevens C, et al. 3D digital scanners: A high-tech approach to more accurate dental impressions. Inside Dentistry. 2009;5(4).

Nulty AB. 3D printing part 1: A history and literature review of 3D printing in dentistry. Preprints. 2021:2021050221.

Prasad S, Abdul Kader N, Sujatha G, et al. 3D printing in dentistry. J 3D Printing Med. 2018;2(3):89-91.

A version of this article was originally published in the October 2022 edition of OnTarget. Read the latest edition and view current promotions at pattersondental.com/dental/ontarget.

At Patterson Dental, we are committed to partnering with dental practices of all sizes to help oral health professionals practice extraordinary dentistry. We do this by living up to our promise of Trusted Expertise, Unrivaled Support every day.

This content was originally published here.

Author: topline

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