Evaluation of Precision of Custom Edentulous Trays Fabricated with 3D Printing Technologies

Purpose: To evaluate the reserved space quantity and printing accuracy of custom edentulous trays produced by two 3D printing methods (fused deposition modeling [FDM] and stereolithography apparatus [SLA]) and to compare them to traditional handmade (HM) methods. Materials and Methods: The tissue surface data of maxillary and mandibular edentulous gypsum models were obtained through a 3D scanner to design the digital custom trays in Geomagic software. The custom trays were then printed with FDM and SLA technologies, and handmade custom trays were used as control. The scanned data of printing trays were registered with their digital data, and the printing errors were analyzed using the deviation analysis function. The distances between the tissue surface of gypsum models and the custom trays were measured in ImageWare and represented by 3D deviation. Results: None of the six groups revealed a significant difference (P> .05) compared to the set value of 1.00 mm. In the SLA group, the deviation of the mandibular area was significantly closer to the set value than for the HM group (P < .05), while no significant difference was displayed between the other groups. For the printing error between the two 3D groups, the SLA method showed significantly less error and better stability (P< .001). Conclusion: 3D-printed custom trays can meet clinical needs in the adaptability of tissue surfaces, and SLA-printed trays revealed better precision and less error than the other two methods. Accordingly, the use of SLA technology to make a 3D-printed custom tray is expected to be promoted in clinical practice.