IADR Abstract Archives
Experimental 3D-Printable Filament Shows Low Warpage After Tempering and Sterilization
Objectives: Fused filament fabrication (FFF) with biopolymers enables a cost-effective and sustainable opportunity to produce clinical appliances such as surgical guides for oral implant installation. During sterilization, shrinkage and warpage can occur. This study aimed to develop sterilizable biopolymer filaments, to be applied in the medical field.
Methods: A commercially available reference material (R) and four biopolymers based on polylactic acid (A, B, C, D) were developed. A, B, C and D differed in the composition of additives. A total of 100 rectangular specimens were additively manufactured using FFF and examined for dimensional accuracy. The samples were divided into two subgroups consisting of 10 specimens per material. The samples of the first subgroup were tempered at 140 °C (T1) after production (T0) and subsequently sterilized at 134 °C (T2). The samples of the second subgroup were directly sterilized (T0, T2), omitting T1. Using a 3D profilometer, the deviations in height and volume were determined. One-way ANOVA and post-hoc Tukey tests were performed for statistical analyses (p<0.05).
Results: At T0, R showed the smallest deviation (-36.01±31.67mm3), followed by A, C, D and B (p<0.05 between all groups). When directly sterilized (T2), R showed the smallest deviation in volume (300.39±194.95 mm3) and comparable deviations in height to B and D (range from 755.6±183.62 to 923.5±323.72 mm). Previous tempering increased the warpage of R. When tempering D, the highest dimensional stability of all materials after sterilization was achieved. The warpage was 77.47% lower in volume and 63.82% lower in height compared to R.
Conclusions: By modifying the composition, a filament (D) with improved dimensional stability after sterilization and previous tempering was developed. For producing clinical appliances such as surgical guides, D might result in a more precise transfer from virtual planning to clinical reality. As a next step, biocompatibility and medical approval need to be addressed.
Methods: A commercially available reference material (R) and four biopolymers based on polylactic acid (A, B, C, D) were developed. A, B, C and D differed in the composition of additives. A total of 100 rectangular specimens were additively manufactured using FFF and examined for dimensional accuracy. The samples were divided into two subgroups consisting of 10 specimens per material. The samples of the first subgroup were tempered at 140 °C (T1) after production (T0) and subsequently sterilized at 134 °C (T2). The samples of the second subgroup were directly sterilized (T0, T2), omitting T1. Using a 3D profilometer, the deviations in height and volume were determined. One-way ANOVA and post-hoc Tukey tests were performed for statistical analyses (p<0.05).
Results: At T0, R showed the smallest deviation (-36.01±31.67mm3), followed by A, C, D and B (p<0.05 between all groups). When directly sterilized (T2), R showed the smallest deviation in volume (300.39±194.95 mm3) and comparable deviations in height to B and D (range from 755.6±183.62 to 923.5±323.72 mm). Previous tempering increased the warpage of R. When tempering D, the highest dimensional stability of all materials after sterilization was achieved. The warpage was 77.47% lower in volume and 63.82% lower in height compared to R.
Conclusions: By modifying the composition, a filament (D) with improved dimensional stability after sterilization and previous tempering was developed. For producing clinical appliances such as surgical guides, D might result in a more precise transfer from virtual planning to clinical reality. As a next step, biocompatibility and medical approval need to be addressed.