Almost everything else works on the surface. Creams, polish, and soaks sit on top of the nail, but the part people actually struggle with sits deep beneath the hard nail plate, down in the nail bed, where surface products simply can't get to.
You work the top, leave the source untouched, and you stay stuck in the same loop that's let you down before.
The Pentachom is built around the opposite idea. It's PDT photodynamic therapy system fires laser diodes across four wavelengths, engineered to pass through the keratin of the nail plate and send concentrated light energy into the nail bed, the exact layer creams are blocked from reaching.
That's the whole difference in one line.
Surface products work on top of the nail. The Pentachom is designed to work at the depth where it counts.