The main cause of periodontal disease is bacterial plaque, a sticky, colorless film that constantly forms on your teeth. However, a number of other factors can contribute to gum disease. These include:

• Hormonal changes such as those occurring during pregnancy, puberty, menopause, and monthly menstruation-make gums more sensitive, which makes it easier for gingivitis to develop.
• Illnesses may affect the condition of your gums. This includes diseases such as cancer or HIV that interfere with the immune system. Since diabetes affects the body's ability to use blood sugar, patients with this disease are at higher risk of developing infections, including periodontal disease.
• Medications can affect oral health because some lessen the flow of saliva, which has a protective effect on teeth and gums. Some drugs, such as the anticonvulsant medication Dilantin and the anti-angina drug Procardia and Adalat, can cause abnormal growth of gum tissue.
• Bad habits such as smoking make it harder for gum tissue to repair itself.
• Poor oral hygiene habits such as not brushing and flossing on a daily basis make it easier for gingivitis to develop.
• Family history of dental disease can be a contributing factor for the development of gingivitis.

There are also other factors which increase your risk of developing periodontal disease such as:

• Tobacco smoking or chewing
• Systemic diseases such as diabetes
• Some types of medication such as steroids, some types of anti-epilepsy drugs, cancer therapy drugs, some calcium channel blockers and oral contraceptives
• Bridges that no longer fit properly
• Crooked teeth
• Fillings that have become defective
• Pregnancy or use of oral contraceptives