Purpose: To evaluate the three-dimensional trueness of upper and lower denture bases produced using a digital light processing (DLP) printer and immersed in a constant-temperature water bath.
Methods: An edentulous model was prepared and fitted with denture bases and occlusal rims manufactured using base plate wax. After scanning the model, denture bases, and occlusal rims, complete denture designs were created. Using the designs and a DLP printer, 10 upper and 10 lower complete dentures were manufactured. Each denture was scanned before (impression surface of upper denture base before constant temperature water bath [UBC] and impression surface of lower denture base before constant temperature water bath [LBC] groups) and after (impression surface of upper denture base after constant temperature water bath [UAC] and impression surface of lower denture base after constant temperature water bath [LAC] groups) immersion in the constant-temperature water bath. Scanned files were analyzed by comparing reference and scanned data, with statistical analysis conducted using the Kruskal-Wallis test (α=0.05).
Results: Statistical analysis revealed no significant differences between the UBC and LBC groups, nor between the UAC and LAC groups (p>0.05). However, significant differences were observed between the UBC and UAC groups and between the LBC and LAC groups, i.e., before and after the constant-temperature water bath for both maxillary and mandibular denture bases (p<0.05).
Conclusion: Denture bases not immersed in the constant-temperature water bath (UBC and LBC groups) exhibited error values within 100 μm, whereas those immersed in the water bath (UAC and LAC groups) showed error values exceeding 100 μm.

Keywords: Color difference map, Complete denture, Denture bases, Digital light processing, Three-dimensional printing, Trueness