Does swallowing the taste of a root canal filling with saliva break one's fast or invalidate it?

The mere presence of the taste of a tooth filling in the throat does not invalidate the fast, because the filling usually does not dissolve and nothing descends from it. Some jurists have held that what does not dissolve does not invalidate the fast just by its taste being present in the throat. Al-Mardawi mentioned in "Al-Insaf" that there are two views on the matter, and one of them is that it does not invalidate the fast, because the mere presence of taste does not invalidate the fast.