Tissue Integration and Biological Cellular Response of SLM-Manufactured Titanium Scaffolds

Background: SLM (Selective Laser Melting)–manufactured Titanium (Ti) scaffolds have a significant value for bone reconstructions in the oral and maxillofacial surgery field. While their mechanical properties and biocompatibility have been analysed, there is still no adequate information regarding tissue integration. Therefore, the aim of this study is a comprehensive systematic assessment of the essential parameters (porosity, pore dimension, surface treatment, shape) required to provide the long-term performance of Ti SLM medical implants. Materials and methods: A systematic literature search was conducted via electronic databases PubMed, Medline and Cochrane, using a selection of relevant search MeSH terms. The literature review was conducted using the preferred reporting items for systematic reviews and meta-analysis (PRISMA). Results: Within the total of 11 in vitro design studies, 9 in vivo studies, and 4 that had both in vitro and in vivo designs, the results indicated that SLM-generated Ti scaffolds presented no cytotoxicity, their tissue integration being assured by pore dimensions of 400 to 600 µm, high porosity (75–88%), hydroxyapatite or SiO2–TiO2 coating, and bioactive treatment. The shape of the scaffold did not seem to have significant importance. Conclusions: The SLM technique used to fabricate the implants offers exceptional control over the structure of the base. It is anticipated that with this technique, and a better understanding of the physical interaction between the scaffold and bone tissue, porous bases can be tailored to optimize the graft’s integrative and mechanical properties in order to obtain structures able to sustain osseous tissue on Ti.