There are several activities that cause periodontal disease that you can control. Be sure to practice good oral hygiene. Eat healthy foods, including the daily recommended intake of vegetables. If you are diabetic, keep your A1C levels under control. Heart disease can also lead to periodontal disease. And, finally, if you are a smoker, make an effort to quit.
There are also other causes that you will not be able to control. For instance, your age and your genetics can add to the cause.