IADR Abstract Archives
Retentive Strength of Orthodontic Brackets Bonded to 3D-Printed vs. Milled Materials
Objectives: The purpose of this study to evaluate the shear bond strength (SBS) of orthodontic brackets bonded to 3D-printed material after various surface treatments and aging in comparison to CAD-CAM polymethyl methacrylate (PMMA) milled material
Methods: sixty cylindrical specimens were 3D-printed and divided into 4 subgroups (n=15 each) according to the surface treatment and aging procedure.
Group A: sandblasted with 50 µm aluminum oxide particles (SA) and aging;
Group B: sandblasted with 30 µm silica-coated alumina particles (CO) and aging; Group C: SA without aging; Group D: CO without aging.
For the control group, 15 CAD-CAM PMMA milled cylindrical specimens were sandblasted (SA) and aged. SBS was tested using a universal testing machine (0.25 mm/min), inspected at 2.5X magnification for failure mode classification and statistically analyzed (P =0.05).
Results: The retention obtained with the 3D-printed material (groups A-D) was higher than that obtained with PMMA (Control group) however, no significant difference was found between the study and control groups except for the groups A and C (SA) which was significantly higher than the control group (PMMA-SA and thermocycling) (P = 0.037 and 0.049 respectively). Study groups A-D predominantly exhibited cohesive specimen mode, meaning fracture of the specimen.
Conclusions: Orthodontic brackets bonded to 3D-printed material exhibited acceptable bonding strength. However, 3D-printed materials were more prone to cohesive failure, which may result in crown fracture
Methods: sixty cylindrical specimens were 3D-printed and divided into 4 subgroups (n=15 each) according to the surface treatment and aging procedure.
Group A: sandblasted with 50 µm aluminum oxide particles (SA) and aging;
Group B: sandblasted with 30 µm silica-coated alumina particles (CO) and aging; Group C: SA without aging; Group D: CO without aging.
For the control group, 15 CAD-CAM PMMA milled cylindrical specimens were sandblasted (SA) and aged. SBS was tested using a universal testing machine (0.25 mm/min), inspected at 2.5X magnification for failure mode classification and statistically analyzed (P =0.05).
Results: The retention obtained with the 3D-printed material (groups A-D) was higher than that obtained with PMMA (Control group) however, no significant difference was found between the study and control groups except for the groups A and C (SA) which was significantly higher than the control group (PMMA-SA and thermocycling) (P = 0.037 and 0.049 respectively). Study groups A-D predominantly exhibited cohesive specimen mode, meaning fracture of the specimen.
Conclusions: Orthodontic brackets bonded to 3D-printed material exhibited acceptable bonding strength. However, 3D-printed materials were more prone to cohesive failure, which may result in crown fracture