Fluoride strengthens enamel. Novamin remineralizes enamel. It "rebuilds" it. How Sensodyne markets it is largely irrelevant.

Indeed, this product targets sensitivity which is exactly what Novamin does (by remineralizing those tiny holes permanently, versus traditional sensitivity products that simply "clog" them temporarily).

Note that Novamin-containing Sensodyne is an overseas thing that you have to import. For whatever reason they didn't seek FDA approval in the US so the product there is sans it.