What - We can see mild to moderate yellow staining on surfaces of teeth, also accumulation of calculus layers on difficult to clean areas of teeth.
Whenever poked with brush or hard stuff usually associated with bleeding in gums.
Why - It is due to improper tooth brushing habits and lack of awareness regarding Interdental Brushes, Floss, Mouth Washes and missed regular Scaling ( Teeth Clening) by dentists.
Habits - Tea, coffee, smoking, Paan eating habit, tobacco in any form, sometimes medicines.