• Cementum is deposited in a thin layer at the cementoenamel junction to form one of the following three configurations:  A butt joint (30%)  An overlap joint (60%)  A gap between cementum and enamel (10%) (this gap may produce cervical sensitivity or may predispose the tooth to cervical caries) • The continued incremental deposition of cementum in the apical third maintains the length of the tooth, constricts the apical foramen, and deviates the apical foramen from the center of the apex. • The surface of the bony crypt becomes known as the lamina dura radiographically. • The sensory nerve fibers traverse the dental papilla and, on reaching the coronal pulp, they branch toward the periphery to form a plexus of nerves called the plexus of Raschkow. • This plexus of Raschkow is located in the subodontoblastic zone of the coronal pulp. • These sensory nerve fibers are myelinated; therefore, they are enclosed in a sheath made of Schwann’s cells. • Human premolars receive almost 2300 axons at the root apex, of which about 13% are myelinated and 87% are nonmyelinated fibers. • Most apical myelinated axons are fast-conducting Aδ fibers. • These fibers are probably activated by a hydrodynamic mechanism and conduct impulses that are perceived as a short, well-localized, sharp pain. • Most C fibers are slow conducting and fine sensory afferents

1.  Cementum is deposited in a thin layer at the cementoenamel junction to
form one of the following three configurations:
 A butt joint (30%)
 An overlap joint (60%)
 A gap between cementum and enamel (10%) (this gap may produce
cervical sensitivity or may predispose the tooth to cervical caries)
• The continued incremental deposition of cementum in the
apical third maintains the length of the tooth, constricts the
apical foramen, and deviates the apical foramen from the center
of the apex.
 The surface of the bony crypt becomes known as the lamina dura
radiographically.
 The sensory nerve fibers traverse the dental papilla and, on reaching the
coronal pulp, they branch toward the periphery to form a plexus of nerves
called the plexus of Raschkow.
 This plexus of Raschkow is located in the subodontoblastic zone of the
coronal pulp.
 These sensory nerve fibers are myelinated; therefore, they are enclosed in a
sheath made of Schwann’s cells.
 Human premolars receive almost 2300 axons at the root apex, of which
about 13% are myelinated and 87% are nonmyelinated fibers.
 Most apical myelinated axons are fast-conducting Aδ fibers.
 These fibers are probably activated by a hydrodynamic mechanism and
conduct impulses that are perceived as a short, well-localized, sharp pain.
 Most C fibers are slow conducting and fine sensory afferents