I almost always read in the news/press that dentists recommend to brush teeth two times a day for 2-3 minutes.
This drives me crazy, because it does not make sense; The point for dental health is to systematical clean every surface of your teeth twice a day (and use inter-dental brushes/floss once a day). For me, brushing my teeth takes around 6 minutes, if I hurry up. For someone faster it might be possible in 1 minute.
So, why do dentists always give the 2-3 minutes recommendation?
The whole point is to not leave starches/sugars in places long enough for a biofilm of plaque to form.
The problem is, teeth are poorly shaped to clean and the interface of the gums is down right hard to get to.
So what they’re trying to do is to get you to clean often enough that you manage to get some of the hard to get areas covered but not so often that you’re sanding the enamel of your teeth.