LCD-based DLP printers: a simplified construction compared with conventional 3D printers with projection technology

Background: Three-dimensional (3D) printing has found several applications in dental technology. Printers based on digital light processing (DLP) offer great accuracy, excellent surface properties and a wide range of printing materials. To simplify the construction, the liquid crystal display (LCD)- based printer, a developed version of DLP printers, uses an LCD panel as exposure mask by means of an ultraviolet (UV) light source. Materials and methods: This study compared 20 standardised test specimens and one working model printed with a conventional DLP printer (projection technology) with models printed using LCD-based technology. The objects were examined microscopically regarding surface properties and peculiarities of the layering and were measured with a digital calliper. Results: Microscopically, both systems showed excellent surface quality. Small fluctuations in the z-axis were found in the objects printed using the LCD technology. The measurements showed deviations of 0.06 to 0.13 mm from the computeraided design (CAD) construction for both systems. Conclusions: Printing results of LCD printers were similar to those of DLP printers. Due to its early development stage, further improvements in the mechanical stability and slicer software are required. Keywords: 3D-printer, accuracy, digital light processing (DLP), LCD