Start brushing his teeth every evening (once a day) small breeds are notorious for having lousy teeth and you may be able to get away with only one or two cleanings per lifetime, see YouTube for how to videos.
Chewing bones are controversial, you could get him a small bone marrow bone (raw) from the market and let him work on it for 20 minutes here and there. Supervised, don’t leave him unattended with it. Raw carrots work too. Be aware that bones can result in GI blockage (even finely ground bone) and broken teeth, anything raw is potentially loaded with bacteria.
For science-based veterinary medicine go here: http://skeptvet.com/Blog/category/nutrition/
Find a vet that you like and trust, listen to whatever advice the breeder has to offer (assuming that her dogs look healthy).
PS: My small breed dogs do well on Nutrisca kibble as a base with a variety of toppers and a splash of water added. See Chewy dot com for reviews.
