Start with a professional dental cleaning/exam at your vet, then give her chewies (safe ones!) and you can even brush her teeth with a toothbrush (canine or people) and some liver flavored toothpaste. Don't use people toothpaste. Baking soda works too but they don't like it the way they do the liver flavored stuff!
I've always used Greenies, but there are reports of deaths happening. I don't know, a dog can die from eating
ANYTHING and hundreds of thousands of Greenwies are sold each year with few problems. It totally depends on
the dog, if it swallows it's good whole, and if you are giving them the right size Greenie for their weight.
They do make a safer Greenie, which does have that large end on one side (which is where the trouble is happening).
I don't remember exactly what it is called. If you go to the butcher and find bones that are safe for your dog to chew
they actually do a great job at cleaning your dog's teeth.
Nothing beats the professional dental cleaning every few years, where they put the dog under and make the dog's teeth
brand new like a puppy. Some people only get this done once in their dog's life (when they're mid age).