How does tartar form on teeth?

Tartar is basically: Calcified plaque. The soft plaque that initially accumulates on teeth, if not removed calcifies to create tartar or calculus. It is best to use a mechanical toothbrush and a water irrigation device as well - easier to use than floss, hence more effective. Also usage of both should be twice a day minimally.

Calcium fr saliva: Tartar is formed on teeth from our saliva. Some of us form it easier than others because some of us have higher calcium content in our saliva. Calcium is the source of the tartar buildup.