A PMR diet, were one feeds 10% soft-edible bones (like raw chicken pieces) along with 10% organs (half of that liver and the rest being secreting organs like kidney, spleen (melts), etc, and 80% "meat" (including muscle, skin, fat, connective tissue, etc) helps optimize dental health by the natural scrubbing action of chewing soft bone plus cutting out carbohydrates from the diet.
The latter, removing carbs, has the biggest impact in my estimation. Dogs lack the ability to produce amylase (the enzyme necessary to digest starches/sugars) in their saliva (unlike omnivores such as humans), so those sugars ferment in the mouth causing discoloration, plaque, tartar and eventually periodontal disease.
Dogs fed a PMR diet, in contrast, are famous for having clean white teeth. My V (about to turn four) has great looking teeth w/o the typical staining, having eaten PMR since 8 weeks.
It is important not to feed hard, weight-bearing bones that can crack teeth, but (that caution aside) I'm fully confident you'd see massive improvements should you go this route vs continuing to feed kibble. If it is just not possible to go PMR, I'd attempt to find the highest protein/fat formula possible as a way to reduce carbohydrates (which are unnecessary in a canine diet in any case).