It depends on the scanner and the dust-removal method it uses.

On many dedicated film scanners, dust and scratch removal is done with a system such as Digital ICE. This uses an infrared scan in hardware to detect dust and surface damage, then software uses that map to repair the image.

Infrared-based cleaning works well with chromogenic color films, including color negatives and many color slides/transparencies. It generally does not work with traditional silver-based black-and-white film, because the image itself interferes with the infrared channel. Chromogenic black-and-white films can work, though. It also typically does not work well with Kodachrome.

For film types that IR cleaning cannot handle, and for reflective originals such as prints, scanners usually rely on software-only dust/scratch removal rather than infrared mapping.

So in short:

• color negative/slide film: often IR-based dust removal is available
• traditional B&W film: usually no effective IR dust removal
• chromogenic B&W film: may work with IR cleaning
• prints: usually software-based cleanup only