Finishing implants and surgical instruments

In the medical industry, finishing is not a cosmetic operation. On an implant, the surface decides whether bone bonds to it or not.

Osseointegration

Osseointegration is the structural and functional connection between living bone and the implant.

One of the factors influencing it is the surface topography of the implant. A surface with controlled roughness gives bone a structure to attach to.

The surface is produced by automated blasting with controlled parameters. The important word is “controlled”: the aim is not simply a rough surface, but a reproducible one, within the same limits, on every part.

What is required beyond the usual

Compared with an ordinary industrial application, three additional requirements appear.

Reproducibility. Every part has to come out the same. Hence the need for automation — an operator, however good, does not manually reproduce a surface within tight limits across thousands of parts.

Absence of contamination. The abrasive must not leave particles in the surface, and the installation must not introduce traces of other materials. Separating the flows by material becomes mandatory.

Traceability. The process is documented. Which parameters, which abrasive batch, which parts.

Instruments

Surgical instruments have different requirements from implants.

Here the aim is usually complete deburring, rounded edges and a smooth surface, easy to clean and to sterilise. Vibratory finishing covers these requirements well, because it processes complicated geometries uniformly too.

Why this is not an application like any other

In an ordinary workshop, a process deviation means a scrapped part. Here it means something else.

Which is why the discussion starts from the medical specification and the required documentation, not from the machine.

Related reading

• Medical Industry
• What is vibratory finishing and what benefits does it bring?
• Finishing titanium alloy implants