Gingivitis can be caused by tartar build-up on teeth. Plaque is made of 60-70% bacteria which release harmful toxins that affect gums. It includes many other factors like smoking, poor diet, aging, lack of proper daily etc. Gingivitis can be cured by using Zinc Citrate Trihydrate toothpaste and maintaining good oral hygiene is also equally important. Read more on gingivitis treatment and prevention.