kibble doesent clean teeth, thats a myth. With that said, dogs kept on all kibble diet vs. those on canned, will probably have cleaner teeth of the 2.
But canned has its benefits, its less processed then kibble, theres more moisture so its easier for dogs to digest and generally better quality, even the crappy brands tend to have more meat in it then their kibble.
I mix some canned with kibble for variety and extra moisture, though I dont buy it often because its too expensive to feed on regular basis. One brand thats a good value and grain free is Whole Earth Farms by merrick.