The objective: It is said that a dog's mouth is cleaner than a human mouth, so I wanted to see if the theory was true. Even though humans brush their teeth, there are still a lot of food particles and bacteria in our mouths. Dog's mouths are supposed to be self-cleaning. I want to test different dog and different human mouths to see who really has the cleaner mouth. My hypothesis states: Cultures taken from a dog's mouth will grow fewer bacteria than cultures taken from a human's mouth.