One of the most important part of having a good oral hygiene is seeing a dentist every 6 month or so to have a clean done. Usually what is done during a dental clean or scaling is removing dental calculus and plaque. most of the time a highly concentrated Fluoride gel or foam will be applied on the teeth afterward. Plaque and build up around teeth and gum will damage the gum if left there for long enough because it contains bacteria and their byproducts which will irritate the gum and cause redness, puffiness and inflammation. Following irritation of gum it will shrink and patient will end up gum recession. In some cases when patient has left the plaque and calculus for long time around gum or at least did not have that cleaned regularly over his/her life time, teeth become loose and fall off by themselves due to gum disease or Periodontitis.