I'm sorry about the teeth/ breath issue! That's the worst. Sounds like you're a good momma though.
According to the
Chicken Soup site: You should brush your dog's teeth 5-7 times per week. This is the best preventive measure for a healthy mouth. However, most of us are unwilling or unable to do just this (NOTE: Not us!). Toys and treats are another way of preventing oral disease that is easier and appealing to most pet owners. Look for treats that have achieved the prestigious VOHC (Veterinary Oral Health Council) seal of approval.
So if the suggestions above didn't work, maybe just try a bone or toys, like the article said? I hope you find your answer soon!