That’s sorta my point.
IIRC, the 2 minutes is the bare-minimum, and intended for someone with perfect teeth and technique. Now most people (ones who aren’t perfect) use the toothbrush, their common reaction to the timer completing is they are done brushing. They don’t realize that they were likely rushing to keep up with the timer and ignoring different plaque hot spots.
I personally have a couple crowns that my previous dentist screwed up on and mis-sized the base, leaving a ledge where food and plaque get stuck in. If I don’t spend extra time around them, tatar will form like a madman. (Same issue with my lingual bar before I had it removed)
I’m alright with a timer to help keep rhythm and let you know when you hit the minimum, but don’t make it integral to using the damn brush and turn it off when it hits zero.
