I know it works because the first time I used it, a fairly large chunk of plaque came loose. Sometimes I feel very small dust-like particles and my teeth feel the same as when I’ve had my teeth cleaned at an expert office; rough, like before they polish the teeth. This roughness soon goes away on its own. I’ve used picks on my teeth, and at times, I’ve been able to knock off larger identifiable chunks. Picks are more effective, but they are a lot more difficult to use. I like this cleaner because it’s easy and pain-free.