Dental cleanings (dental prophylaxis) are usually performed by Registered Dental Hygienists but may also be performed by the dentist. Your cleaning appointment will include a dental exam and the following:

Removal of plaque: Plaque is a sticky, almost invisible film that forms on the teeth. It is a growing colony of living bacteria, food debris, and saliva. The bacteria produce toxins (poisons) that inflame the gums. This inflammation is called gingivitis and is the start of periodontal disease!

Removal of tartar: Calculus (tartar) is hardened plaque that has been left on the tooth for sometime and is now firmly attached to the tooth surface. Calculus forms above and below the gum line, and can only be removed with special dental instruments called scalers.
Polishing: Removes stain formed on the teeth by such things as nicotine, coffee or tea.