The aim was to evaluate the surface roughness (Ra) and shear bond strength (SBS) of novel polymethylmethacrylate (PMMA)-based materials. Thirty rectangular specimens were prepared from three different PMMA-based materials: nanographene-reinforced PMMA, milled PMMA, and self-curing PMMA. All specimens underwent a polishing process and the Ra value was then recorded using a non-contact profilometer. A special plate was then used to bond nanoflowable composite resin to the specimens' surfaces, after which they underwent thermocycling between 5 and 55 °C for 5000 cycles. The SBS was subsequently evaluated at a crosshead speed of 1 mm/min. One-way ANOVA and Tukey's HSD test (α = 0.05) were used for data analysis. The Ra and SBS values differed significantly ( p < 0.001). The self-curing PMMA specimens had the highest mean Ra value (1.15 μm), while the G-CAM specimens had a mean Ra value of 0.55 μm and the milled PMMA specimens had a mean Ra value of 0.53 μm. SBS in the milled PMMA group was measured at 51.25 MPa; SBS in the G-CAM and self-curing PMMA specimens was lower than in the milled PMMA specimens (34.36 and 31.22 MPa, respectively). Although nanographene-reinforced PMMA exhibited an acceptable Ra value, its SBS value was lower than that of milled PMMA.

(1) Purpose: To compare the fabrication accuracy, internal fit, and marginal adaptation of three-unit definitive resin fixed dental prostheses (FDPs) produced by subtractive milling and additive manufacturing. (2) Materials and Methods: A typodont mandible was prepared for a three-unit FDP, with full crown preparations on teeth mandibular left canine and mandibular left second premolar featuring 1 mm chamfer finish lines. The FDP was designed with a 16 mm² connector and a 100 µm cement gap. Two milling materials (Ambarino High-Class, IPS e.max CAD) and two experimental 3D printing hybrid resins (3D-1, 3D-2) were used. All restorations were scanned using an intraoral scanner and compared to the original STL using reverse engineering software for surface trueness and deviation analysis. The internal fit was evaluated using the triple-scan method, while marginal fit was assessed via micro-CT imaging. Statistical analysis was conducted using one-way ANOVA and Kruskal–Wallis tests (α = 0.05). (3) Results: Milled groups demonstrated a lower prevalence of external, marginal, and overall surface deviations (p < 0.001), while 3D-1 exhibited comparable deviations within the internal region with M-E (p = 0.067). Milled groups had average gap values that were similar to 3D-1 (p > 0.08), but significantly lower than 3D-2 (p < 0.002). In marginal adaptation evaluated by micro-CT, the M-A and M-E groups provided significantly lower gaps, while the 3D-1 and 3D-2 groups exhibited wider marginal and axial gaps. (4) Conclusions: These results indicate that while milling remains a more reliable manufacturing method for achieving external and marginal precision, position 3D-1 is a compelling, chairside alternative to milling.

Purpose: To investigate the surface roughness (Ra), shear bond strength (SBS), and Vickers hardness number (VHN) of additive manufactured interim resins manufactured through different vat polymerization techniques.Methods: Samples were divided into four groups; additive manufacturing technology (Stereolithography:S-FL; Digital light processing:D-AS; Liquid crystal display:L-PH) and subtractive manufacturing technology (Polymethylmethacrylate: MP) (n = 10). After polishing, the Ra values were measured and resin material was then applied. Following thermocycling, SBS tests and VHN tests were carried out. The obtained data were evaluated using one-way analysis of variance (ANOVA) (a = 0.05).Results: Significant differences were observed between the groups for SBS (P = 0.02) and VHN (P < 0.001), whereas the Ra values were not statistically significant (P = 0.148). D-AS and L-PH had higher and similar SBS (P = 1.000) while MP had statistically lower SBS. D-AS demonstrated higher VHN than all groups (P < 0.001) with the exception of S-FL (P = 0.831). MP had lower VHN than all groups (P < 0.01) other than L-PH (P = 0.143).Conclusion: All fabrication methods had clinically acceptable SBS values, L-PH and D-AS had higher results. D-AS demonstrated superiority in terms of VHN, all groups exhibited comparable Ra values.