While the merits of one brand of dog food over another are up for debate, in general, the type of dog food you choose can have an advantage when it comes to his dental health. Dry dog food is generally better for your dog's oral health than wet food, but if yours won't eat it, you can supplement a wet food diet with special treats and toys.
Wet Vs. Dry
In general, dry food is better for your dog's teeth. Because of its crunchy texture, when your dog chews up kibble, it sweeps away plaque and debris that collect in his mouth. Bigger kibbles can be more effective at this than smaller kibbles, and are even sometimes marketed as such. The resistance and texture of dry food doesn't just help with plaque and tartar, either -- it exercises your dog's jaw, keeping it strong and healthy.
Because it's the texture of dry kibble that helps your dog's teeth -- and not necessarily the nutritional ingredients -- you can use toys to clean your dog's teeth. This way, if your dog refuses to eat dry food, you can still give him something to sweep away plaque and tartar. For example, if your dog chews on a hard toy like one made of rubber or hard plastic, or if he chews on a rawhide as a treat, that chewing scrapes the surface of his teeth and cleans them.
If you feel so inclined, you can also offer your dog treats that are specially formulated just to keep teeth clean. These chewy treats are often shaped specifically to maximize the amount of brushing and scraping that happens inside your dog's mouth. You may also brush your dog's teeth yourself, using a toothbrush and toothpaste designed for dog mouths. Unlike humans, though, your dog doesn't need a twice-daily brushing -- every two or three days is plenty.
Making a Switch
If you want to switch your dog from wet food to dry in an attempt to improve his dental health, consult your vet first -- you should always talk to a veterinarian before making a major alteration to your dog's diet. You will have to make the transition gradual, slowly mixing more and more dry food with less and less wet food, as a sudden switch is bad for your dog's digestive system. You may also notice that your dog drinks more water, as kibble doesn't provide your dog with the water content of moist food.