3D printing is being used more and more in the field of dentistry. It is used here by dentists, dental technicians as well as orthodontists. These rely on both 3D printers and 3D scanners, some of which were created specifically for these applications. The production of dental bridges, implants, dental crowns and the like can be significantly shortened in time by using this technology. In addition, less material is also consumed than in conventional manufacturing (especially) in the dental sector. Patients in particular benefit from a service tailored to their individual needs.
Denture models, crowns, bridges and bite splints from the 3D printer
For example, a 3D scanner and a 3D printer can be used to make wax models of the dentition. Such a wax model then serves as the basis for 3D printing bite splints, surgical guides and the like. Until now, these impressions always had to be made with a so-called impression tray and impression compound, which is very unpleasant for some patients. A 3D scanner captures the data of the dentition, which is then converted into a 3D file on the computer with the help of software.
In the main, however, the technology is used for the production of dental crowns, bridges and dental implants. As a rule, metal processing 3D printers are used here, as the new teeth have to withstand a considerable amount of force (chewing) – over the long term.
Potentials of dental 3D printing
In 2015, additive manufacturing in the dental industry generated the equivalent of approximately $780 million in revenue. The market research company Smart Tech Publishing expects sales to grow to more than $3 billion in 2020. At the same time, the market for digital dentistry is also continuing to pick up. In 2016, for example, EnvisionTEC recorded a 75 percent increase in sales compared to the previous year. Sales are also likely to have increased significantly in subsequent years.
Main applications of dental 3D printing
Among other things, 3D printing is used for
- the investment casting,
- the direct manufacturing of dental equipment and for restorations,
- the production of drilling templates and dental tools
Among other things, investment casting is the production of patient-specific crowns and bridges. The object to be produced is then made from liquid material poured into the mold. The materials that can be used include ceramic and metal.
In the production of dental equipment, the respective product comes directly from the 3D printer. This can be a metal tooth crown, for example.
A third major area is the production of surgical drill templates as well as dental tools. Here, too, the object comes directly from the 3D printer. For example, the stencils can be made from specific resins used in processes such as stereolithography (SLA).
Advantages of additive manufacturing in dentistry
Conventional fabrication of a bridge, crown or other dental prosthesis usually requires two or three weeks. By using the – partly intraoral – 3D scanners as well as a 3D printer (partly with milling unit) it is possible to reduce this period to two to three days. In some dental offices, the bridge or implant is also printed immediately and placed in the patient during the same session.
More and more printing materials are coming onto the market, especially for dental applications. While there were about 20 approved materials by the end of 2017, it is expected that ten to 20 more will receive their approval in 2018 alone. Depending on the class of material, the approval process can take up to three years.
Another advantage is that even with a small print bed, several items can be produced in one operation.
Which 3D printing processes can be used?
The 3D printing processes in the context of dentistry are either stereolithography (SLA), fused deposition modeling(FDM), digital light processing (DLP), ProJet/MultiJet printing (MJP) or direct metal printing (DMP).
SLA and DLP 3D printers work with different resins. This resin is in a special tank and is cured to the desired object by a laser or projector. They are mainly used for the wax melting process and can reproduce molds for this purpose. Similarly, they are suitable for the direct fabrication of final objects such as bite splints. The technology works very precisely and can even achieve a resolution of up to 20 micrometers. The resin can also be used to make 3D printing molds for investment casting, which in turn can serve as the basis for further 3D printing with other materials.
Powder Bed Fusion technology is used by metal 3D printers. Metal powder in a wide variety of compositions is available for manufacturing. Metal 3D printers are costly, but their purchase can quickly pay for itself with regular use. One of the most common production methods is Direct Metal Laser Sintering (DMLS). It can be used to produce high-quality objects without sacrificing quality compared to conventional manufacturing.
3D scanner in dentistry
Among the important dental devices in the 3D printing theme world are 3D scanners. Not everyone likes it when impressions have to be taken of their dentures. Often, a kind of gag reflex occurs first and foremost. With a 3D scanner, the information can be obtained more straightforwardly. These devices must be highly accurate so that the mouth and dentition can be realistically represented.
Two different types of 3D scanners can be used in dentistry. One is intraoral and the other is desktop 3D scanners.
The intraoral 3D scanner creates colored three-dimensional images of the denture or dentition of a patient. These devices are inserted into the mouth and then create a highly accurate color 3D model. This model is then modified by software, enabling the fabrication of a new crown, bridge or prosthesis.
Desktop 3D scanners use structured light technology (either white or blue light) while being fully enclosed. In the scan chamber, the exposure should be fully controlled. With these devices it is possible to determine the digital data based on conventional dental impressions. A high image resolution should also be considered for these scanners. The acquisition costs for these mobile devices are in the four- or five-figure range. Desktop scanners from 3shape, for example, cost from around 2,500 euros. Those who only want to perform a few scans or test the technology first can also rent such a device.
Some manufacturers also offer packages consisting of a 3D scanner and a 3D printer for purchase. As a rule, these two devices are then also compatible with each other. If good technical support is added to this, the purchase pays off even more.
In the coming years, many dentists, dental technicians and orthodontists will continue to invest more heavily in 3D printing and 3D scanning. Simply because of its detail, variety and accuracy, 3D printing has significant potential in dentistry. Since some companies are also looking to expand their range of dental-ready 3D printers, it makes perfect sense to check out the higher-priced 3D printers (ready-to-use printers) and 3D scanner models as well. In most cases, these devices work much more professionally, and may even have been approved for industrial use.