All periodontal disease begins with plaque formation. In other words, without plaque formation you wouldn’t get gum disease.
Plaque is initiated when millions of disease-causing germs attach themselves to the tooth by releasing a gluelike substance. These germs can attach to what appears to the naked eye as a perfectly smooth tooth surface but, to the plaque, is actually not smooth at all. They especially love areas of the tooth that don’t get cleaned properly, rough spots where decay has already started, pits and defects, and overhanging fillings. They also love the gingival crevice, the little groove where the tooth meets the gum, and the gum pocket, because these areas offer them a protected place to hang out.
But germ alone — even those that initiate plaque formation, no matter how many are attached — are not considered plaque. As more and more germs congregate, however, they are able to snag the other materials that contribute to plaque formation, such as food particles, minerals, and other germs. Once all of the ingredients have joined together, and this can occur in as little as one hour after brushing, you have officially begun to form plaque.
At this point, and up to about four hours after this sticky and nearly invisible substance has formed on your tooth’s surface, the plaque is vulnerable to all forms of oral cleansing. But if you give it more than four uninterrupted hours to establish itself, it becomes a lot tougher to remove. Left longer than that, plaque can adhere pretty solidly to the tooth, and in most cases, even brushing won’t remove it all. You may scrape off the top layers, but the part that is most firmly attached to the tooth will usually remain. This makes it easier for the next layer of plaque to form, and it can begin to do so immediately after the next brushing. Remember, plaque can form in the absence of food, so even if you fast you will still have to keep brushing.