To have PowerPoint slides in front of you is one thing, but you should feel confident even when there is nothing on the screen in front of you. The idea is to be confident with the content and message you deliver to people. Just because most PowerPoint presenters use ppt slides it does not means at all that you have to have PowerPoint slides on your screen all the time.
There is a very powerful technique to use a blank or completely black screen during your presentation. This trick is well-known among all professional presenters and public speakers, as they that that when there is nothing on the screen, the target audience starts focusing on the presenter and his speech. That is why, you should use this technique every time when you want to deliver your own point of view without being distracted by any kind of visuals.