Journal of Dentistry, cilt.166, 2026 (SCI-Expanded, Scopus)
Objectives: This study evaluated the effects of different surface finishing procedures on the mechanical properties and cytotoxicity of a 3D-printed interim fixed dental prosthesis (IFDP) resin. Methods: A mechanically polished conventional acrylic resin (C-MP) and a milled block mechanically polished (M-MP) were used as controls. A 3D-printed (3DP) resin was used in five different surface finishing procedures [no procedure (NO), optiglaze/intraoral curing (OI), optiglaze/extraoral curing (OE), armaglaze/extraoral curing (AE), and mechanically polished (MP)]. For each group, bar and disc-shaped specimens (n = 15) were obtained. A three-point bending test was conducted at a crosshead speed of 1 mm/min. Flexural strength and flexural modulus were evaluated. The fractured pieces were tested for Vickers micro-hardness (VHN) (n = 5). Traditional colorimetric tetrazolium-based reduction assay (XTT) and a real-time cell analysis (RTCA) system were used to assess the eluates' cytotoxicity on cultured L-929 mouse fibroblast cells. Data was analyzed with one-way ANOVA, followed by Dunnet T3 or Tukey's tests (α = 0.05). Results: There was no statistically significant difference between the mean flexural strength of the printable resin with different surface finishing protocols (p > 0.05). The mean flexural modulus of 3DP-OE was significantly higher than the mean of control groups, 3DP-NO, and 3DP-MP (p < 0.05). C-MP group had the lowest mean VHN (7.1 ± 1.2) (p < 0.05). All groups showed cell viability higher than 70% in XTT. The 1:1 concentration of C-MP had the lowest mean cell survival rate of 87.04%. RTCA results were consistent with XTT results. Conclusions: A 3D-printed IFDP resin with different surface finishing procedures demonstrated favorable mechanical and biological properties. Different surface finishing procedures affect flexural modulus and VHN of the IFDP resin. Clinical significance: Glazing or mechanical polishing is recommended for 3D-printed IFDP resin, and it should be considered that the wear of the surface layer may be affected by the applied finishing procedure. Long-term wear resistance, staining, and intraoral aging should be evaluated in future research.