Wouldn't worry too much if the whitespot's gone already. You might get a secondary outbreak, but if you keep the temperature up around 30 degrees celsius and add a little salt (livebearer salt works just as well as NaCl/sea salt), it shouldn't come back, or at least not as badly. Alternatively, you can always go ahead and use malachite green or any of the other popular whitespot cures they market, but I find it's not always necessary.