The puppy breath that puppies experience is caused by the teething process that puppies go through.
The puppy breath usually starts going away within 7 to 8 months and after 7 to 8 months of age the puppy should have it's full adult teeth and the puppy should no longer experience puppy breath.
Some people think that puppy breath smells awful but to me the smell of a puppies breath during teething is a good smell.
But we all like different things.