IADR Abstract Archives
Optimisation of Printing Parameters to Improve Properties of 3D Printed Dental Products
Objectives: Objectives: To investigate the effects of post cure temperature and time on the spatial degree of conversion (DC) in specimens produced with stereolithographic (SLA) printing.
Methods: Method: Tensile test bars (ASTM D638) were sketched using CAD software (Fusion 360, Autodesk) and printed using a photocurable resin (Clear v4, Formlab) in a SLA printer (Form2, Formlab). Specimens were post-cured with 405nm floodlight light (Form Cure, Formlab) for exposure times of 0-60 minutes and temperatures of 21°C to 60 °C. Spatial mapping of DC was assessed using a FTIR-microscope (Nicolet iN10 MX, Thermo-Scientific in attenuated total reflectance mode in 50 µm increments within the gauge length of the tensile test bar (2x2mm2) in X-Y directions. The aliphatic/amide II (isosbestic peak) peak height ratio of cured specimens was normalised against uncured materials measured on a Nicolet 6700 (Thermo-Scientific). Printed tensile test bars were tested using a universal testing machine (MTS Criterion) to calculate tensile strength and Young’s Modulus at a strain rate of 1mm/min. Data was analysed using regression, Analysis of Variance and post-hoc Tukey comparisons (p=0.05).
Results: Results: Specimens post-cured for 60 minutes at 60°C showed significantly higher DC than those cured at lower temperatures and times. Spatial mapping of DC demonstrated local effects of DC relating to printing parameters (layer thickness, print direction and specimen height). Tensile strength was significantly dependent on print direction and post cure conditions (p<0.05).
Conclusions: Conclusion: Parameters affecting 3D printing quality is multifactorial and if not controlled may affect clinical and mechanical performance of 3D printed products. Printing conditions require optimisation to achieve adequate physical / mechanical properties.
Methods: Method: Tensile test bars (ASTM D638) were sketched using CAD software (Fusion 360, Autodesk) and printed using a photocurable resin (Clear v4, Formlab) in a SLA printer (Form2, Formlab). Specimens were post-cured with 405nm floodlight light (Form Cure, Formlab) for exposure times of 0-60 minutes and temperatures of 21°C to 60 °C. Spatial mapping of DC was assessed using a FTIR-microscope (Nicolet iN10 MX, Thermo-Scientific in attenuated total reflectance mode in 50 µm increments within the gauge length of the tensile test bar (2x2mm2) in X-Y directions. The aliphatic/amide II (isosbestic peak) peak height ratio of cured specimens was normalised against uncured materials measured on a Nicolet 6700 (Thermo-Scientific). Printed tensile test bars were tested using a universal testing machine (MTS Criterion) to calculate tensile strength and Young’s Modulus at a strain rate of 1mm/min. Data was analysed using regression, Analysis of Variance and post-hoc Tukey comparisons (p=0.05).
Results: Results: Specimens post-cured for 60 minutes at 60°C showed significantly higher DC than those cured at lower temperatures and times. Spatial mapping of DC demonstrated local effects of DC relating to printing parameters (layer thickness, print direction and specimen height). Tensile strength was significantly dependent on print direction and post cure conditions (p<0.05).
Conclusions: Conclusion: Parameters affecting 3D printing quality is multifactorial and if not controlled may affect clinical and mechanical performance of 3D printed products. Printing conditions require optimisation to achieve adequate physical / mechanical properties.