Aside from its common worse effects to health like heart disease, stroke, lung cancer or other respiratory diseases, smoking is also a major cause of tooth decay and gum disease. Smoking directly affects the mouth, and so the teeth and gums and soon lead to oral cancer. Smoking contributes to tooth decay and gum disease as it compromises the flow, amount and function of saliva in the mouth. Saliva is important for cleaning the lining of the mouth and teeth. The flow of saliva helps to counteract mouth acids that cause decay and protects the teeth from wearing away. The calcium in saliva helps to prevent tooth decay. Smoking reduces blood flow to the gums and cuts the supply of vital nutrients. It can also reduce the vitamin C levels needed to maintain healthy gums. It also raises the mouth's temperature, damaging and killing important cells and tissues in the mouth. Getting a regular dental examination is a way to screen for the risk of oral cancer. Of course, it is very important to maintain good oral hygiene to prevent tooth decay and gum disease. Practice good hygiene by flossing and brushing daily. One of the our best defense against tooth decay and oral cancer is to stop smoking.