Dental health is important. Biotene is useful along with brushing and such, but I didn't notice much difference in my dog's breath. Overall, I'd say her mouth health has improved, though.
I use this after brushing with an enzymatic "tooth paste" if my dog's gums are red/bleeding. It really does the trick to settle the inflammation and they do not mind the taste. I have not noticed a difference in their breath, but I think the antibacterial effect is meaningful.