A dentist score between 0 and 4 indicates zero is the best you can get, meaning your gums are in excellent condition, and four indicate gum disease. The numbers your dentist hears calling for are the depths of the pockets around your teeth in millimeters. Smaller, tighter pockets often mean healthier gums. The numbers you hear are the depths of the cavities around the teeth in millimeters.
Along with the numbers mentioned with respect to pockets, there will be a correlated number referring to which tooth is affected. That way, it's easy for the attending dental hygienist to note where the problem pocket is located. We measure this distance in millimeters. As a patient, you'll want to hear a smaller number.
This means that you have a smaller space between the tooth and the gum, a sign of a healthy mouth. A higher or higher number indicates that you have gum problems, such as plaque and tartar buildup.