PURPOSE: The purpose of this in vitro study was to incorporate microparticles into a commercially available 3D printed denture base resin and compare its mechanical and biological properties with the conventional polymethyl methacrylate (PMMA) denture base material.
MATERIAL AND METHODS: Microparticles were collected from milled zirconia blanks and were blended with a 3D printing denture base resin (NextDent Denture 3D+). The optimal zirconia microparticle content (2%) for blending and printed was determined by using a liquid-crystal display (LCD) 3D printer. The printed specimens were then postrinsed and postpolymerized based on the manufacturer's instructions. Mechanical and biological characterization were carried out in terms of flexural strength, fracture toughness, and fungal adhesion. One-way ANOVA was carried out to analyze the results statistically.
RESULTS: The incorporation of microparticles in the 3D printed denture demonstrated higher mechanical strength (104.77 ±7.60 MPa) compared with conventional heat-polymerized denture base resin (75.15 ±24.41 MPa) (P
METHODS: A 160-mm-diameter PLA head CTDI phantom with five dosimetry holes was fabricated using fused deposition modeling. Its elemental composition, density, effective atomic number, electron density, Hounsfield units (HU), and CT dosimetry parameters were characterized. Measurements were performed on 128-slice Ingenuity Philips and GE Discovery scanners, at 80, 120, and 140 kV. CTDI was measured at two different times and then compared with PMMA.
RESULTS: PLA showed properties close to PMMA, with differences of 5.08% in density, -0.015% in effective atomic number, and -4.46% in electron density. PLA HU values were lower than PMMA, ranging from 22.5 to 45.3 HU on Philips and 25.1-49.1 HU on GE. CTDIvol deviations between PLA and PMMA ranged from -9.00% to -2.82% in November 2025 and from -5.78% to -3.83% in June 2026. These deviations remained within <10%, which was generally considered acceptable for comparative phantom-based CT dosimetry.
CONCLUSION: The PLA CTDI phantom showed good effective atomic number, electron density, and dosimetric agreement with the standard PMMA phantom across two CT systems and two measurement time points.
IMPLICATIONS FOR PRACTICE: 3D-printed PLA CTDI phantom could offer a practical, low-cost complementary tool for comparative CTDI measurement, education, protocol optimization, and quality assurance.
METHODS: Two 3D printed models were designed and fabricated using actual patient imaging data with reference marker points embedded artificially within these models that were then registered to a surgical navigation system using 3 different methods. The first method uses a conventional manual registration, using the actual patient's imaging data. The second method is done by directly scanning the created model using intraoperative computed tomography followed by registering the model to a new imaging dataset manually. The third is similar to the second method of scanning the model but eventually uses an automatic registration technique. The errors for each experiment were then calculated based on the distance of the surgical navigation probe from the respective positions of the embedded marker points.
RESULTS: Errors were found in the preparation and printing techniques, largely depending on the orientation of the printed segment and postprocessing, but these were relatively small. Larger errors were noted based on a couple of variables: if the models were registered using the original patient imaging data as opposed to using the imaging data from directly scanning the model (1.28 mm vs. 1.082 mm), and the accuracy was best using the automated registration techniques (0.74 mm).
CONCLUSION: Spatial accuracy errors occur consistently in every 3D fabricated model. These errors are derived from the fabrication process, the image registration process, and the surgical process of registration.