"But how do you know when it's time to change the brush?"
Well, how about when it starts getting soft?
"But how do you know when it's time to change the brush?"
Well, how about when it starts getting soft?
[0] I'm either easy on toothbrush heads, or Philips is lying, because when the indicator says "buy a new head" it still has plenty of life IMO. Bristles straight and tall, just like a new one, but no blue left being the only difference between that and new. So I ignore it and get a new one when the bristles go a little wonky.
Could be. My wife presses so hard, I hear the motor bog down. "JFC, honey, let up a bit", to no avail. She's constantly replacing her heads. I literally can't remember the last time I popped a new one on mine. I could easily believe it's been six months (and, yeah, it's about due).
a dental hygienist told me to hold it with just the thumb and forefinger.
I can't quite manage that, but if you look at how drummers hold their sticks, it's never in a fist. Their arms wouldn't last through one show like that.
So if you at least take your little finger off it, the amount of pressure goes down.
Watch Roy Mayorga.
https://drummagazine.com/roy-mayorga-the-soulfly-interview/
I'm not a drummer, so I shouldn't make blanket statements like that, I guess. I always thought they held the sticks loosely.Look at Ginger Baker & Elvin Jones, from 0:56 on.
https://www.youtube.com/watch?v=bFTvZl8G9Z4
Or Roy Haynes:
toothbrushes come with documentation???
No more, no less.
One is not enough.
Three is too much.
Four is right out.
if you brush for 2 minutes but don't get enough passes over each square mm of surface area, you have done a bad job of brushing
instead of watching the clock, imagine each of those surface areas and make sure you hit them
plus gums, tongue, roof of mouth, etc.
You might be interested in this YouTube video from Applied Science with electron micrographs of 'new' and 'worn' toothbrush bristles - there is a very marked invisible change that happens: https://www.youtube.com/watch?v=cwN983PnJoA
They used to provide color rings to attach to the head, in order to differencing.