Many raw diet proponents claim that the nutrients and/or chemical composition of a raw diet keeps dogs from developing gingivitis or periodontitis. We’re not aware of any studies that have proven these claims, but the persistence of the anecdotal evidence of this phenomenon (to say nothing of its evolutionary success) suggest that there are dental benefits to a diet that includes raw, meaty bones.
Interestingly, it’s not just the physical action of the chewing; many owners, who fear the potential for bone fragments to impact or perforate their dog’s intestines, use commercial food grinders to grind raw meaty bones into a fine paste before feeding them to their dogs. Many of them report the same dental advantages as those who feed whole raw meaty bones to their dogs.
Again, there are likely to be outliers – dogs whose teeth and gums develop disease even when fed a supremely healthy raw diet.
However, it’s been our experience that people are either open to the idea of feeding a raw diet (whether commercial or home-prepared) or not; the condition of their dog’s teeth may be a contributing motivation, but not the sole factor guiding the decision.
I agree that it is not just physical scrubbing of the teeth with raw, meaty bones that keep the teeth clean with a raw diet. The species appropriate diet gives the entire GI tract a species appropriate and healthy microflora– That includes the mouth. Carb fed kibble dogs not only have nutritional deficiencies that contribute to structural problems and immune problems but also grow pathogenic bacteria in their mouths that cause periodontitis. It is also believed that the live enzymes in raw meat chemically contribute to cleaning of the teeth. Chewing action gets a lot of saliva flowing as well and the chewing exercises the dental ligaments and increases blood flow to the gums. All good, all natural and all important.