The tooth collar is the border point where the crown ends and the roots begin, in other words it is a transition area between the enamel and the cement.
In subjects not affected by any pathology it is normally covered by the gum, but in the case of gingival recession it is uncovered and can become sensitive to heat and cold.
It is thus exposed to bacterial aggression which, together with incorrect brushing, will lead to tooth decay or a deep incision which causes severe pain.
