That is very interesting. I guess it seems intuitive kibble would accumulate less debris on the teeth, but it wouldn’t be the first time intuitive is wrong.
Most cats don’t actually chew their dry food.
Some just hawk it back without any or much chewing.
It really never is chewed long enough to rub and clean the teeth.
And in some cases works like bread in our mouths.
The dry food could get mushy and get stuck on teeth and sit there.
I’m sure all of us have had bread sit in a molar and needed to be dug out with your tongue or brushing.
Wet and dry food. Neither helps teeth cleaning at all.
But wet food is considered better for cats because of the water content. Cats in the wild don’t normally drink much water. They get some of it from the fresh, wet kill.
From what I read, dry food can leave a lot of kitties dehydrated much of the time.
I wish I could feed my cats wet food exclusively, but they are addicted to the kibble. (I call it cat crack. LOL)
I am hoping that feeding them wet food at night might help in some way. Who knows really.