Product does a superb job of cleaning any particles of food (or whatever) from your teeth. It can be a bit messy with water spraying everywhere if you're not careful.
My dental hygienist kept telling me that I should use a waterpik because my flossing habits are not the best, so I finally bought an ultra unit and I have been amazed at how it works. I always thought just brushing my teeth would get rid of food particles, but after using this for six weeks I have been amazed that after I brush I use this and and it always does a great job of cleaning out the stuck particles that are left after my brushing. My only complaint is that my reservoir valve sticks once in a while and I have to tap it to get it to work.