With the development and exploration of resin 3D printers in the field of 3D printing dentistry, light-curing 3D printing equipment that claims to be applied to dentistry are flourishing. Due to the high requirements for precision and accuracy in dental applications, accuracy has become the main consideration when choosing equipment. However, the higher the accuracy, the better the printed dental application effect will be?

What does "precision" mean?

3D printing equipment often gives an accuracy index, which is also the main basis for people to generally judge the accuracy of the equipment: "Make the guide plate, the accuracy is 75um? Pass! The accuracy is 50um, OK!"

In fact, what we are comparing is only the working parameters of a single accessory on the equipment, and does not represent the overall accuracy of the equipment.

More than 90% of 3D printing technologies are in a layered stacking mode. Simple understanding is like a sandwich. Pieces of different shapes are stacked together to become a three-dimensional model. The forming effect of each piece, and the superimposed transition effect between pieces, respectively represent its horizontal accuracy and vertical accuracy. The "precision" marked by various types of equipment is actually only a horizontal plane accuracy parameter.

What is the difference between horizontal accuracy and vertical accuracy?

The horizontal plane accuracy is the accuracy of the XY axis. It is the image structure capability of the molding surface and the theoretical effect of the optical components of the device.

SLA is a laser spot scanning forming, similar to using a pen to paint color blocks. Therefore, its XY axis accuracy parameter refers to the smallest diameter of its pen tip (spot), about 80-120um.

The forming methods of DLP and LCD are similar to two-dimensional codes, and an image is composed of many small squares. Each small square is a single pixel, and its size is the minimum image construction capability, that is, the XY axis accuracy parameters of DLP and LCD.

3D printing is a three-dimensional model, so in fact, it also has requirements for vertical accuracy of layer to layer. Just like a sandwich of the same size, the thinner the thickness of each layer, the greater the number of pieces, the better the layer-to-layer transition, and the finer the vertical surface.

This accuracy parameter is the subdivision of the thickness of the molding surface, the minimum is 25um, which is determined by the minimum stride of the Z-axis motion accessories. The layer thickness can be set in the printing parameters, like steps, a step is 25um high, we can choose to walk one step or several steps at a time.

Therefore, the accuracy of the equipment is only based on a single XY axis accuracy parameter for comparison, which is too one-sided. and! Regardless of whether the Z-axis accuracy parameters or the XY-axis accuracy parameters are good, these indicators are actually the accuracy capabilities provided by the accessories, which can provide us with a reference value for the accuracy of the setting, but cannot describe the printing capabilities of the device.