Color me a skeptic.
See 2014 comments by Dr. Jennifer Coates on PetMD, "
Dry Food and Dental Disease in Dogs."
She mentions differing results from research about doggy dental issues from 1930's, '40s, '60s, 1996 and 2007 as well as "several recent studies."
The 2007 study "looked at the effects of the size of the kibble in 40 beagles and found that increasing the kibble size by 50% resulted in a 42% decrease in the accumulation of dental tartar."
The beagle study really hit home for me. Our vet gave me a stern talking-to after my late little one's dental, 2004-2005. Based on her bite and the size of her mouth, he selected a kibble for Katy as an alternative the kibble I had been offering and the chicken she loved. I thought his pick was too big...he said it was bigger and that was the point!
The PetMD article talks about recent studies showing "that adding a daily dental chew to diets of dogs fed 'regular' dry dog food results in better oral hygiene than does dry food alone."
We know these little ones are prone to dental issues. If this is multiple choice, I'm going for all-the-above, which includes daily brushing and regular vet dentals, etc.