Raw is much better for their teeth then canned or kibble. The grain in kibble causes plaque and tarter buildup and canned food tends to be a little more sticky and sticks to their teeth causing plaque and tarter as well. Lacy had a little tarter along her gum lines around the time we stopped feeding kibble and started feeding raw. There has been no more tarter buildup at all on her teeth in the year I've fed her raw. I'm going to clean her teeth this summer just to get that small amount of tarter off because I don't think I'll have to have her teeth cleaned again since she's on raw. I do also brush her teeth once a week though - I think that is neccessary no matter what food you feed. I compare her teeth to my cat who ate kibble for years, and I had to clean her teeth at least once a year - sometimes every six months because the tarter is so bad. Kibble doesn't help clean teeth - it would be like eating a cookie or cracker and expecting it to clean your teeth - it doesn't.
I switched my older cat to canned and raw when i got my new cat who also eats canned and raw. My older cat doesn't like the raw much so I mix it with some canned and there hasn't been a problem there. So I don't think it would hurt your dog to still have some canned if you want to do that. Just make sure it's a high-quality canned food and grain-free would be best. Nature's Variety also makes some grain-free canned food (my cat eats their canned food), and Merrick makes good canned food. If the canned has grain in it, I wouldn't feed it too close to the raw for the same reasons as not mixing kibble and raw.
A lot of people are afraid of feeding their dog raw food, but dogs aren't people and have different digestive tracks than us. People weren't made to eat raw food. Bacteria in the food can make us very sick. Dogs however have a shorter digestive tract and the food doesn't stay in system as long so the bacteria doesn't have time to multiply and make it sick. Dogs in the wild always ate raw meat (animals they killed). Also, this is why your dog can eat some nasty decaying bird outside and not deathly ill. The bacteria in raw won't hurt your dog unless it is already immunocompressed and really susceptible to bacteria making it sick. Healthy dogs are just fine with the bacteria in raw. Plus with Nature's Variety, the know the food is meant to be eaten raw and they prepare it and handle it in a way that it should be safe to be eaten raw.
Here is what Nature's Variety says about raw being best:
http://www.naturesvariety.com/conten...1329KyP421FC6D
Why the bacteria in raw won't hurt your dog:
http://rawfed.com/myths/bacteria.html
Myths about raw:
http://rawfed.com/myths/bacteria.html
This is a great FAQ page: (BARF means Bones and Raw foods - another name for RAW - alot of this though is for people that mix their own raw)
http://www.njboxers.com/faqs.htm
Another FAQ about raw (might answer more questions):
http://www.rawlearning.com/rawfaq.html
Hope these help