Effect of denture cleansing solutions on physical properties of 3D-printed and heat-polymerized denture base resins

Background This study aimed to compare the effects of various denture cleansing solutions on the flexural strength, surface roughness, and microhardness of heat-polymerized PMMA and two 3D-printed denture base resins. Methods Specimens were fabricated from heat-polymerized PMMA and from Saremco Denturetec and PowerResins Denture Resin 3D-printed resins. Three denture cleansing solutions (Aktident, Corega, and Protefix) and distilled water as a control were evaluated using a continuous 45-hour immersion protocol. Flexural strength was assessed by three-point bending, surface roughness by profilometry, and microhardness by Vickers testing. Statistical analyses were performed using the General Linear Model procedure in Minitab. Results Material type significantly influenced flexural strength ( p < 0.001) and surface roughness ( p < 0.001). Heat-polymerized PMMA showed the highest flexural strength (131.49 ± 35.90 MPa) and surface roughness (1.823 ± 0.473 μm), whereas the 3D-printed resins showed lower values. Cleansing solutions significantly affected microhardness ( p = 0.018) and surface roughness ( p = 0.018). Significant material–solution interactions were found for surface roughness ( p < 0.001) and microhardness ( p < 0.001). Aktident produced the highest microhardness values (25.25 ± 3.75 VHN), while Corega produced the lowest (22.99 ± 2.69 VHN). Conclusions Heat-polymerized PMMA exhibited higher flexural strength and surface roughness than the two 3D-printed denture base resins. Cleansing solutions affected surface roughness and microhardness but not flexural strength, with significant material–solution interactions indicating differences in surface responses among the tested materials. These findings should be interpreted considering differences in surface preparation and the limitations of the in vitro design.