I give them the occasional raw frozen beef marrow bone because I know they enjoy it.
I don’t think food, bones/chews, sprays or additives work any miracles on their teeth, though.
I brush their teeth with Petrodex and a medium sized adult toothbrush (hardest I can find), I count to 100 (for each section) and really scrub the sides and the back where the tartar builds up, this takes about 5 minutes for each dog per day.
Some dogs just have lousy teeth, sometimes it’s genetic, and will need one or two professional cleanings in their lifetime no matter what you do. But the brushing does make a big difference.
