Most of the intrinsic discoloration encountered in everyday practice is caused by the breakdown of blood products of the pulp
tissue, due to trauma or a traumatic incident (Figure 7-7).This type of discoloration (ie, blood degradation) occurs during hemolysis,
when iron is released from hemin, hemosiderin, hematin, and hematoidin.Through the addition of the bacterial product hydrogen
sulfide, iron is converted to ferric sulfide, resulting in the discoloration of the tooth.The dental enamel tends to change color either
to orange, brown, or dark gray in color (Figure 7-8).