Cleaning is a procedure during which tartar is removed. Tartar is mineralized plaque, which forms from bacteria that stick to the surface of the enamel, saliva and food. If soft plaque isn’t removed in time with a toothbrush or dental floss, it will mineralize and harden creating tartar which can only be removed by a dental hygienist or dentist.
Remaining tartar, especially located subgingivally, is a habitat for bacteria and may cause inflammation of the gums and periodontium (periodontitis) later on. Still however, the main cause of these diseases are bad oral hygiene caused by ineffective brushing and not flossing.
A regular cleaning is recommended every six months. However this time period is good for the average person and may vary depending on your tendency to form tartar and plaque.
The doctor decides how often cleaning should take place, knowing the patient's condition and his individual predispositions.