Osteogenic Comparison on Selective Laser Melting Printed and Sandblasting-Acid-Etching Ti Substrates for Customized Implant Applications

Implants treated by sandblasting acid etching (SLA) have been demonstrated to be capable of hastening the osseointegration process. However, they suffer from some shortcomings, which include contamination by the grit-blasting materials and residual acid solution, as well as limited satisfaction of certain requirements for oral use. As an alternative procedure that enables the fabrication of customized implants with complex geometries, the use of selective laser melting (SLM) to fabricate implants has recently drawn considerable attention. In the present work, SLM-printed substrates were compared with commercially available SLA-treated plates in terms of their surface characteristics and biological performance. The wettability and roughness of SLM-printed substrates were found to be significantly better. Moreover, in vitro evaluations revealed that the SLM surface facilitated the attachment and proliferation of human bone marrow mesenchymal stem cells (hBMSCs), and induced accelerated osteogenic progression, as indicated by the observed increased alkaline phosphatase (ALP) activity, elevated expression of osteo-related mRNA, and intense calcium deposition. Overall, the SLMbased substrates exhibited suitable cytocompatibility and osteophilic properties, which are expected to enhance in vivo bone-implant contact and osseointegration. A comprehensively optimized SLM-printed substrate mimics a more osteophilic environment and affords an alternative means of producing customized implants in oral implantology.