[throwaway287391]

Right but the question is for how long? Surely you're not supposed to never put water in your mouth again, so how long should you wait? 1 minute? 10 minutes? An hour?

[Darmody]

30 minutes according to some dentists I know.

I used to rinse my mouth with water, now I just spit the toothpaste.

I haven't asked but this may be recommended only if you're not using an abrasive toothpaste which could damage your teeth enamel.

[klyrs]

Depends what you're optimizing for. If you never eat or drink anything again, your teeth will stay healthy until you die...?

I've heard dentists recommend brushing after every meal. Which really doesn't seem realistic for people who snack or regularly drink coffee / tea.