In a prior article, the Sacramento Dentistry Group focused on the current uses for 3D printing in dentistry. The common applications at this time are for short-term appliances that are only used for a few weeks, or for soft, protective devices such as nightguards and mouthguards. New developments and FDA approval for a process by a new company named Carbon may be changing that, especially for clients that need dentures.
CLIP — Not Just Layers of Plastic
When people think about 3D printing today, they visualize a machine that lays down a resinous material on a platform, building layer upon layer to generate a part or finished product. Improvements are constantly being made to this procedure, but there are critical deficiencies in the method. When finished, the part is much like a layer cake, and at each junction between layers, there is a potential for weaknesses.
In contrast, Carbon uses a process they call CLIP — Continuous Liquid Interface Production. If you have ever needed a filling or tooth bonded, you’ve experienced part of what makes the CLIP process work. Dentists often fill holes or chips in teeth with a soft, gooey resin. The resin is easily shaped, but too soft to be any use in its natural form. To harden this resin and give it the necessary strength, dentists then cure it with ultraviolet (UV) light. CLIP uses a similar procedure to create solid parts out of liquid resin.
First, an object image is digitally loaded into a CLIP machine. A platform is dropped down to the bottom of a small vat of liquid resin. At the bottom of the vat, a UV light shines an image of the desired part through a screen that repels the resin. Thus the resin doesn’t attach to the screen, but it does attach and solidify on the platform above, in the shape of the projected light. As the platform rises, the shined images are altered so that the entire part is made, rising up out of the vat as the resin cures. At the interface between the screen and the base of the forming part there is a constant flow of new resin, thus the name CLIP. Since the part is constantly in contact with the source resin, the layering common to ordinary 3D printing is absent. Therefore, the potential strength of the manufactured part is much higher.
Advantages of CLIP Printing
Because of the strength and detail possible with CLIP technology, the Food and Drug Administration has cleared the use of dentures created solely from liquid resin printing. The technology is still in its infancy, so the Sacramento Dentistry Group is watching for additional reports and studies on the effectiveness of CLIP-printed dentures. While we are constantly on the lookout for new technologies to benefit our patients, we do not want them to feel like “guinea pigs” by the hasty adoption of newer techniques. Trust our dentists to pay close attention to the ongoing developments in dental 3D printing and to bring them to our downtown Sacramento practice when the cost and benefits warrant their use!