Desenvolvimento de suspensão fotossensível de porcelana dentária para impressão 3D via Digital Light Processing

Abstract

The objective of this study was to develop a photosensitive dental porcelain suspension for 3D printing via Digital Light Processing (DLP). To this end, two samples of experimental glass were ground to average particle sizes of 3 μm and 10 μm, characterized in terms of particle size distribution, and used to make pressed compacts and suspensions with a 40:60 (by volume) ratio of powder to liquid medium, and different proportions (1, 2, 3, 4, and 5% by weight) of BYK 111 dispersant, which were subsequently tested for rheology. The composition with 4% dispersant was chosen because it presented the most suitable rheological behavior and was used to compose two experimental groups: Pressed Dental Porcelain with 3 μm and 10 μm, PDI 3 and PDI 10, respectively. Three other groups were tested: Pressed Dental Porcelain (PDP) with 3 μm and 10 μm (PDP 3 and PDP 10), and the control, C, composed of pressed IPS e.max Ceram powder. The samples from the groups were characterized by SEM, EDS, and XRD (analyzed by the descriptive method) and physically-mechanically (density, roughness, and hardness), and the results were submitted to Kruskal-Wallis statistical tests followed by Dunn's post-test with a significance level of 5%. The results showed that the PDI 3 group had a dense microstructure more similar to that of group C. The groups with an average particle size of 10 μm showed crystallization peaks in the XRD analysis (regardless of the manufacturing method). The PDI 3 group had the highest Vickers hardness (median = 3,6 ± 0,5 GPa) with a statistically significant difference from the other groups. The PDI 10 group exhibited the highest surface roughness values (median Ra = 1,21 ± 0,8 μm), with a statistically significant difference compared to the others. Regarding relative density, groups C (98,3% ± 1,0%), PDP 3 (95,3 ± 0,3%), and PDP 10 (95,1% ± 1,1%) presented the highest values, while groups PDI 3 (86,5% ± 2,3%) and PDI 10 (75,7% ± 7,7%) resulted in lower densification. It is concluded that, using the methodology adopted, it was possible to develop a viable suspension for 3D printing of dental porcelain via DLP using particles with an average size of 3 μm.

The objective of this study was to develop a photosensitive dental porcelain suspension for 3D printing via Digital Light Processing (DLP). To this end, two samples of experimental glass were ground to average particle sizes of 3 μm and 10 μm, characterized in terms of particle size distribution, and used to make pressed compacts and suspensions with a 40:60 (by volume) ratio of powder to liquid medium, and different proportions (1, 2, 3, 4, and 5% by weight) of BYK 111 dispersant, which were subsequently tested for rheology. The composition with 4% dispersant was chosen because it presented the most suitable rheological behavior and was used to compose two experimental groups: Pressed Dental Porcelain with 3 μm and 10 μm, PDI 3 and PDI 10, respectively. Three other groups were tested: Pressed Dental Porcelain (PDP) with 3 μm and 10 μm (PDP 3 and PDP 10), and the control, C, composed of pressed IPS e.max Ceram powder. The samples from the groups were characterized by SEM, EDS, and XRD (analyzed by the descriptive method) and physically-mechanically (density, roughness, and hardness), and the results were submitted to Kruskal-Wallis statistical tests followed by Dunn's post-test with a significance level of 5%. The results showed that the PDI 3 group had a dense microstructure more similar to that of group C. The groups with an average particle size of 10 μm showed crystallization peaks in the XRD analysis (regardless of the manufacturing method). The PDI 3 group had the highest Vickers hardness (median = 3,6 ± 0,5 GPa) with a statistically significant difference from the other groups. The PDI 10 group exhibited the highest surface roughness values (median Ra = 1,21 ± 0,8 μm), with a statistically significant difference compared to the others. Regarding relative density, groups C (98,3% ± 1,0%), PDP 3 (95,3 ± 0,3%), and PDP 10 (95,1% ± 1,1%) presented the highest values, while groups PDI 3 (86,5% ± 2,3%) and PDI 10 (75,7% ± 7,7%) resulted in lower densification. It is concluded that, using the methodology adopted, it was possible to develop a viable suspension for 3D printing of dental porcelain via DLP using particles with an average size of 3 μm.