When a design calls for a metal orthopedic prototype — a trial implant, a jig, or a fixture geometry too complex to machine — the choice usually comes down to two additive processes: DMLS and SLM. Both fuse metal powder layer by layer with a laser, and both can produce titanium and cobalt-chrome parts strong enough for functional testing. The difference that matters for a prototype program is less about the acronym and more about what each process is optimized for.

DMLS: built for a wider material mix

Direct Metal Laser Sintering sinters powder particles together rather than fully melting them. It handles alloy powders — including cobalt-chrome and some proprietary blends — that don't always behave predictably under a full-melt process. For orthopedic work that needs a specific alloy for biocompatibility or a downstream sterilization requirement, DMLS is often the more flexible starting point.

SLM: fully dense, more predictable mechanical properties

Selective Laser Melting fully melts the powder into a continuous, dense structure. That tends to produce more consistent mechanical properties from build to build, which matters most once a prototype moves toward functional load-bearing testing rather than a form/fit check. Titanium (Ti-6Al-4V) is the most common material here for orthopedic applications.

Where this fits in a prototype program

In practice, the choice is rarely made in isolation — it's paired with the part's stage in development. Early form studies often don't need metal at all (SLA or SLS plastic is faster and cheaper). Once a design is stable enough to test fit against real bone models or instrumentation, metal additive earns its cost. Lab Ready reviews the application, load case and material requirement before recommending a route, and can combine DMLS or SLM with CNC finishing on critical surfaces where the as-printed tolerance isn't tight enough on its own.

If you're not sure which process fits your next revision, send the part details and target use — the answer is usually a five-minute conversation, not a guessing game.