Same situation happened for me. Was arrested, charges were dropped and the judge took the rare step of issuing a written order that found me "Factually Innocent." He then ordered for the sealing and obliteration of all records related to the incident. Further, he advised me that this order now gives me the right to legally answer "no," should I ever be asked if I've been arrested.
Since the aforementioned incident was so recent, I knew the records weren't fully sealed and would obviously show up. Therefore, I obviously brought it up at the interview. While my factual innocence finding is helpful in other many other circumstances, he made it very clear that it didn't matter one iota for them. All they care about is whether or not you were found guilty (or there was an admission of guilt on your part). Assuming you can prove the charge was dismissed or you were not guilty, they'll approve you.