Plaque is caused by not brushing properly! It doesn't matter if you brush 50 times a day if you're not doing it right! Ask your dentist or a parent to show you the correct way! They used to come to school & teach us but, I guess they don't do that anymore! Everyone has to be taught how to brush properly, it's not just you! I taught my kids! * It's excessive, hygiene, floss, plaque & causing!
Plaque buildup on your teeth can be caused by a lot of different things including lack of regular flossing, eating too much sweets and lack of vegetables in ones diet. You will need to visit a dentist to get that plaque scraped off and check for any tooth decay. Check out http://www.webmd.com/oral-health/healthy-teeth-10/plaque-causes?page=2 for more details.