Help my dogs teeth are falling out!?

My little Doggy, his teeth are falling out, ive taken him to the vets and he has told me to brush them for him, and i have some chicken flavour toothpaste but my dog hates having his teeth brushed, (he will not let me brush them, due to being sore) he has wobbly teeth and bad bacteria on the wobbly ones which im worried will spread to others, then what will he eat???