I'm bad about staying paleo at this time, so I usually just use regular toothpaste.
But, my preference is baking soda whether I'm using toothpaste or not. I like to use it with the toothpaste. It's mildly abrasive and neutralizes acids. I find my mouth feels a LOT cleaner and stays feeling clean for longer if I use it. Tastes like crap, but that's okay. I don't use much water when brushing with it, except for when rinsing.
I've also considered adding peppermint essential oil to it when I get some. I believe that's antibacterial, as most essential oils are, far as I know.