This study compared the mechanical and bonding properties of conventional stainless steel (SS) band and loop space maintainers with cobalt-chromium (Co-Cr) three-dimensional (3D)-printed appliances fabricated using selective laser melting, and evaluated the effects of loop thickness and band design. A total of 90 specimens were prepared and subjected to 5,000 thermocycles. Fracture strength was measured using a universal testing machine, and bond strength was calculated from the debonding load and bonding area. Failure modes were assessed using the adhesive remnant index and field emission scanning electron microscopy. Fracture strength significantly differed among groups (p p p = 0.061 and p = 0.151, respectively). For debonding load, both the conventional and 3D-printed circumferential groups showed significantly higher values than the 3D-printed partial-coverage group (p p = 0.015). The 3D-printed circumferential group showed significantly higher values than the partialcoverage group (p = 0.011), while no significant differences were observed between the conventional and 3D-printed groups (p = 0.360). Within the limitations of this in vitro study, the 3D-printed Co-Cr space maintainers showed no statistically significant differences in mechanical and bonding performance in several comparisons, suggesting that they may be considered an alternative to conventional space maintainers under certain conditions.
Song et al. (Tue,) studied this question.