Yes, as a general rule, you still should be able to use the approved H-1B petition to apply for an H-1B visa and work in the U.S. and your prior B-1/B-2 denials shouldn't impact your H-1B visa application since the reason(s) for those denials aren't reasons to deny an H-1B visa application. Make sure to retain counsel however because you should talk through your H-1B visa application and subsequent entry to the U.S.