
There was a visible difference in my son's teeth after one day!
There was a visible difference in my husband's teeth after two days!
There was a visible difference in my teeth and my daughter's teeth after just one week!
(Yes, that is a lot of exclamation marks - but, WOW! We LOVE our toothbrushes!)
Now let me warn you, as the instructions did: The first time you use it, it really tickles and is uncomfortable - your gums and lips get all tingly. You want to stop before the two minute timer is done. That is okay. The next time you use it, it is much better - you at least know what to expect. By the second full day of using the Sonicare, you notice the "tinglies" but it is not an issue. After that, it is all just routine and completely comfortable.
Oh, another warning: make sure you keep your lips closed unless you want beautiful splatters all over your bathroom! :)