I compare tartar to when your car has so much caked on stuff that even if a monsoon rain comes down, it still looks dirty (ahem...my car always looks like this by the way). No matter how much you brush or floss, that tartar is just not coming off! But whyyy???
If plaque is not efficiently removed on a daily basis with brushing and flossing, it builds on itself and eventually becomes a rock-like substance we then call, tartar (calculus). Prolonged exposure of tartar can lead to bleeding gums (gingivitis), and eventually, bone loss (periodontitis). Therefore, it is pretty important to be consistent not only at home with your oral hygiene routine, but also in keeping with your dental exam and cleanings every 6 months.