Special Needs Dental Clinic Selective laser melting (SLM) or direct metal laser sintering (DMLS) is a rapid prototyping, 3D printing, or additive manufacturing (AM) technique designed to use a high power-density laser to melt and fuse metallic powders together.In many SLM is considered to be a subcategory of selective laser sintering (SLS). The SLM process has the ability to fully melt the metal material into a solid three-dimensional part unlike SLS.