For what it’s worth - Sensodyne uses a finer grit abrasive than many other brands. Might be a better choice if trying to repair cd scratches.

The US Sensodyne (sans Novamin) or the regular Sensodyne that every one else gets?

I am in the USA. Wasn’t aware there are different types under that name.

Novamin turns into hydroxyapatite, like in Japanese toothpastes. Fluoride and nanohydroxyapatite work better together than either alone, for carries at least. The approval process is too expensive to get through here, even though nanohydroxyapatite is used regularly in many countries.