There are. The first thing you should do is ensure that your software is updated, as this can sometimes solve the problem. Otherwise, you can go to https://play.google.com/store/apps/details?id=com.smart.swkey&hl=en, and download what amounts to a patch. So long as the rest of your screen is working, it creates virtual buttons on top of where the capacitive buttons usually are. If this doesn't solve the problem, you may have to consider replacing the screen.