After the first use, I admit I thought about returning! The ad speaks of a more effective brushing and softer, but it was not my first impression. The vibrations on the teeth are quite violent and painful ... limit! I am told that adjustment period was necessary and that is what happened, even if it is not perfect yet: thus, when part of the brush hairs other than contacts with the teeth, it is extremely unpleasant. Finally, I will say that this is fortunately effective, but I wonder if my fillings will hold up ;-) I do recommend that people with healthy teeth and perfectly aligned (mine we tend to overlap).