Intraoral scanners, CAD/CAM software, digital processing, CAD/CAM milling machines and, last but not least, 3D printers mean a digital evolution in dentistry. Digital technologies are becoming more and more accessible and widespread, which is why we are also more interested in this area in order to provide you with useful information. In this article, we focused on 3D printers for your dental practice or laboratory.
Why should you consider 3D printing for your practice?
The use of 3D printing and the digitalization of procedures in general brings undeniable advantages both for patients and for surgeries and laboratories in the form of increased work comfort, time savings, shorter production processes and, last but not least, there are economic aspects, where in many cases 3D printing is clearly cheaper than conventional manufacturing. Compared to conventional "manual" procedures, digital procedures are also attractive due to their repeatability, where you get the same result every time, even after a while. 3D printing also solves some of the technical limits of CAD/CAM milling machines.
The development of 3D printing is really rapid – new manufacturers of equipment, materials and accessories are appearing on the market, big players in dentistry are establishing cooperation with 3D printer manufacturers and rebranding them so that they too have 3D printing in their portfolio. This means that 3D printing has already become an integral part of production in dentistry. Dental and orthodontic models, gingival masks, surgical and implantology templates, combustible models of restorations, fixed bridges and skeletal restorations, temporary crowns and bridges, orthodontic splints and protectors, transparent braces, ortho lock carriers, impression spoons, suction cups and other individual tools sterilizable in an autoclave.
How to choose your 3D printer?
There are already dozens of different devices available at very different price levels, from the order of hundreds to machines with a purchase price of 40 000 €. For easier orientation, we therefore offer you an overview of the main features of a 3D printing solution - not only a 3D printer is enough, but you need a complete set of several devices.
Is SLA, DLP or LCD 3D printing technology right for me?
SLA (Stereolithography)
The UV laser beam gradually coats/hatches the image of each layer. The advantage is a possible larger working area, the non-illuminated area is completely black, so there is no unwanted hardening outside the print area and a constant light output is ensured. Disadvantages include slower printing, dimensional distortion and reduced edge sharpness. The size of the irradiated spot is different for the "center" and different for the "outer position" of the laser. This technology was developed especially for prototyping.
LCD (Liquid Crystal Display)
The UV LED field illuminates the entire layer at once through the LCD display, which transmits light only at the points where curing is to occur. Printing is thus much faster and the purchase price is attractive due to the simplicity of the design. However, the LCD display ages and reduces its throughput. This changes the luminous flux and it is necessary to constantly monitor and adjust the exposure time. The cone-shaped surface illuminated by the LED field then causes a loss of print accuracy. Residual light is partially transmitted to the unilluminated surface, resulting in an unwanted partial hardening of the monomer chains outside the print area, which float in the material and uncontrollably attach to the surface of the printed objects. Due to this technological deficiency (uncontrolled imperfect polymerization of the surrounding parts of the monomers), 3D printers of this type are not so suitable for biocompatible printing.
DLP (Digital Light Processing)
A special chip similar to that of a data projector, composed of millions of small mirrors, redirects the UV light from a strong source to each point (pixel in the shape of a square). Again, the entire layer is illuminated at once, all points are the same size and only the intended ones are illuminated, resulting in very high speed, accuracy and sharpness. The unilluminated surface is perfectly black, and therefore there is no unwanted hardening that we mentioned with LCD technology. However, these qualities of DLP devices are redeemed by a higher purchase price.
Do I need to print with 405 nm or 385 nm wavelength?
3D printers are actually polymerizers that turn liquid resin into a solid model. Products produced by 3D printing technology can be used in the oral cavity, for example, implant templates, fixation, whitening or protective splints, temporary or removable dentures, invisible braces or impression spoons, etc. For all these products, it is absolutely necessary to ensure high-quality polymerization in the entire volume of the product in order to completely prevent cytotoxic effects on the patient's organism. So it is really important to have a perfect cure!
The wavelength of 385 nm, which can only be found in DLP printers, is more effective for curing and enables the printing of biocompatible class IIa materials with a lower content of toxic substances. It does not cause unwanted yellowing of the material (important e.g. for retention plates and temporary dentures, which have the exact shade of color according to the VITA swatch). It can also be used to print materials intended for polymerization at a wavelength of 405 nm.
The wavelength of 405 nm is the most widely used, more common in LCD 3D printing technology and can also be found in DLP printers. Only a small amount of materials for this wavelength is biocompatible and only on the surface, and even then it requires more demanding and expensive post-production.
Do I want an open or closed system?
Closed systems have the advantage that the manufacturer can simplify the whole system more, because he knows what and how it will be used. Material profiles are tuned to achieve consistent results. Such a system is usually a bit easier to use. However, this is redeemed by a lifetime "bond" to purchase more expensive material from this manufacturer, using only one software, licenses and losing the ability to gain a competitive advantage thanks to new materials on the market.
Open systems, on the other hand, provide much more freedom in what material you use, you can choose the software (slicer) that best matches your ideas and that you find more user-friendly. This gives you the opportunity to use your system for more and more applications. As an example, let's cite new materials for direct printing of transparent braces. An open system does not necessarily mean experimenting and preparing your own settings. Some manufacturers provide tuned third-party material profiles for their printers and can print with them in no time and without labor.
How much 3D printing resolution and accuracy do I need?
Based on technological differences, there is a big difference between 50 µm in X/Y on an LCD printer and on a DLP. You can successfully use an LCD with such a resolution on orthodontic models. With a certain amount of effort, you can maintain the profile for a limited time after a few attempts, even on split dental models, where it is required that the pins fit precisely into the base. With a DLP printer you can achieve a repeatable result without experimenting. As a result, the size of the point (pixel) in X/Y is important, which depends on the size of the print area and the quality of the smoothing of the edges, depending on the resolution.
How much printing space is enough for me?
This is very individual, it often leads to the pursuit of the largest possible surface to print as many models as possible at once. A large area has larger printing points, the lifting mechanism is more stressed, ensuring the correct thickness of the layer on which the buoyancy of the printed material acts. The mechanism must therefore be sufficiently powerful and precisely engineered to ensure sufficient accuracy in the Z-axis. This is reflected in the purchase price. There is no one-size-fits-all machine, so it's a good idea to clarify what your case is. When you repeatedly print the same type of product from the same material, then a large volume is an advantage for you. If your production is more focused on different types of work, you will appreciate, for example, two machines, where one has a larger area and the other a higher resolution. On one you print dental models and the other is for ultra-detailed printing of temporary restorations and skeletons, or is available when something needs to be printed quickly.
It must work!
If you want your printing solution to just work, you don't want to buy a toy, you don't have the desire and time to play with the printer to find out how to set everything up through a lot of experiments and studying discussion forums on the Internet, you will be interested in the following features:
- Automatic power regulation - the same light output throughout the life of the printer guarantees that you never have to adjust print profiles, you just print and get the same result even after a while.
- Uniform backlighting - it is important that the entire surface is illuminated evenly, otherwise dimensional inaccuracies occur across the printing surface. Some LCD printers use optical systems to ensure maximum uniform illumination, the best achieve a difference in light intensity of 10%, the best DLP printers achieve a difference of only 0.1%.
- Temperature regulation in the printing chamber – it is better to print at a temperature of 35 °C, higher quality materials are denser, this will reduce their viscosity and the influence of the environment, printing is of higher quality, more reliable and faster.
- Accuracy in the Z axis – some 3D printers available on our market have a high-quality mechanism supplemented by a sensor system for precise control of the height of the print layer. This is important not only for ensuring high print quality and maintaining optimal mechanical resistance of the product, but also from the point of view of homogeneous and full polymerization of each print layer to ensure the biocompatibility of the product.
- Unstuck - detecting separation and then moving the platform back - ensures faster printing and increases success when printing closed volumes.
- Material Profiles - tuned by the manufacturer containing all environmental variables, in addition to exposure length, tolerances, shrinkage, print temperature, light output, viscosity, buoyancy, movement speed and timing.
- Remote access - 3D printing can be significantly simplified and facilitated by sending the job remotely over the Internet, starting it remotely and monitoring its status.
- Support - any innovation of your processes will only go smoothly if you have a partner available who supplies complete equipment, knows his devices intimately including their limits, has enough experience, is able to train you, integrates the devices into practice and is willing to help when you encounter a setback or introduce a new procedure or material.
Buy a 3D printer or use 3D printing services?
If you already know that 3D printing is right for your practice or laboratory, it is reasonable not to regret the time devoted to trying out and "getting your hands on" this technology. This way, you avoid investing in something that only works on paper or with disproportionate effort. A very common approach is to include 3D printed products in the process first in the form of custom printing at another company. After some time, you will be able to more easily assess the benefits of digitization and 3D printing for you. There are companies on the market that are able to deliver 3D prints from the digital model you send within 1-2 days. For this, they use equipment of the highest classes, which will provide them with the assurance of achieving the highest possible quality and the possibility of quick delivery of finished works.
Do you want to bring your idea to life? Contact us for professional advice in SLA 3D printing. We will design the most suitable material, handle the complete production of your product, or deliver and help integrate the manufacturing process, including the technology.
Learn more about our 3D printing services, explore the consultancy offered, or schedule a meeting directly.
