Evaluation of Root-Analog Implants and Standardized Specimens Fabricated by Selective Laser Melting

To evaluate root-analog implants (RAIs) fabricated by selective laser melting (SLM).

Two types of implants (a maxillary right first molar RAI and a screw-cylinder-type molar implant) were designed using CAD software. Both implant types were fabricated with the SLM technique using Ti-6Al-4V powder. The stress distribution and micromotion of the implants were evaluated using finite element analysis, and the mechanical properties of the printed implants (relative density and compression test), surface properties of an SLM-fabricated specimen (morphology, roughness, and contact angle test), and biocompatibility of an SLM-fabricated specimen (osteoblast attachment, metal ion precipitation analysis, cell viability, and osteogenic gene expression) were evaluated.

The RAI model exhibited better stress distribution and less micromotion than the screw-cylinder implant model. The screw-cylinder implant was better than the RAI at withstanding pressure, but both implant types could withstand masticatory forces. The densities of both implant types were similar to those of the bulk materials. Block samples made using the same SLM technique as the RAI exhibited good surface properties and excellent biocompatibility.

The properties of the molar RAI fabricated with the SLM technique suggest that it may have potential for future clinical use, but this will need to be verified by in vivo studies.