I bought 2 bottles of Plaque Off, didn't help. Then I read their OWN RESEARCH that says helps for 5 wks then plaque increases. When their own research doesn't support it, cheap though it is, you have to wonder if it helps. But every vet site says none of the sprays, additives or anything helps more than minimal– brushing is critical. I should also add until I stopped feeding raw, I never had to brush a dog's teeth. Now even Cara at almost 3 has a bit of plaque so am now brushing HER teeth (though only 3 x a week, not every day like Arwen).
I REALLY wanted the plaque vaccine to pan out. When it came out, my vets (who are cautious) said to wait a couple of years. Well, it has been found safe, but they discontinued it as it doesn't work. I really need a miracle. Though the truth is, she is good about it now and heck, I spent more time grooming the chow 2x a week than I do brushing her teeth every night. I still have to get them cleaned every 3 mos though. My vet recommended trying a water pik. ROFLMAO, me and what army? Sigh. So we just keep getting them cleaned. For the record, she isn't forming tartar, it is the actual plaque her gums react to.