PulpPulp

The dental pulp is the soft connected The dental pulp is the soft connected tissue that supports the dentin. tissue that supports the dentin.

Four distinct zone in Four distinct zone in pulp pulp

Odontoblastic zone- at the pulp periphery Odontoblastic zone- at the pulp periphery Cell free zone of Weil – beneath the Cell free zone of Weil – beneath the

odontoblastodontoblast Cell-rich zone – where the cell density is Cell-rich zone – where the cell density is

high high - seen easily in coronal pulp - seen easily in coronal pulp adjacent to the cell free zoneadjacent to the cell free zone

Pulp core – characterized by the major vessels Pulp core – characterized by the major vessels and nerves of the pulpand nerves of the pulp

Odontoblast Odontoblast

The most distinctive cell of the pulp The most distinctive cell of the pulp and the most easily to recognized. and the most easily to recognized.

The number of odontoblast is The number of odontoblast is estimated in a range of 59,000 to estimated in a range of 59,000 to 76,000 per square millimeters in 76,000 per square millimeters in coronal dentincoronal dentin

The cervical loop area: (1) dental follicle cells, (2) dental mesenchyme, (3) The cervical loop area: (1) dental follicle cells, (2) dental mesenchyme, (3) Odontoblasts, (4) Dentin, (5) stellate reticulum, (6) outer enamel epithelium, Odontoblasts, (4) Dentin, (5) stellate reticulum, (6) outer enamel epithelium,

(7)inner enamel epithelium, (8) ameloblasts, (9) enamel.(7)inner enamel epithelium, (8) ameloblasts, (9) enamel.

FibroblastFibroblast

The cells occuring in greatest number The cells occuring in greatest number in the pulpin the pulp

Particularly numerous in coronal Particularly numerous in coronal portion of the pulp, wherethey form the portion of the pulp, wherethey form the cell rich zone. cell rich zone.

The function of fibroblast is to form and The function of fibroblast is to form and maintain the pulp matrix, which consist maintain the pulp matrix, which consist of collagen and ground substance.of collagen and ground substance.

Appear as flattened spindle-shaped cell Appear as flattened spindle-shaped cell with dense nuclei.with dense nuclei.

Undifferentiated Undifferentiated ectomesenchymal cells ectomesenchymal cells

Represents the pool from which Represents the pool from which connective tissue cell of the pulp are connective tissue cell of the pulp are derived.derived.

This cell are found throughout the This cell are found throughout the cell-rich area and the pulp core and cell-rich area and the pulp core and often are related to blood vessels often are related to blood vessels

Appear as large polyhedral cell Appear as large polyhedral cell possessing a large, lightly stained possessing a large, lightly stained centrally placed nucleus. centrally placed nucleus.

Macrophages Macrophages

Tend to be located in the pulp Tend to be located in the pulp center.center.

Appear as a large oval or spindled Appear as a large oval or spindled shaped cells.shaped cells.

Pulp macrophages are involved in Pulp macrophages are involved in the eliminations of dead cells the eliminations of dead cells

Lymphocytes Lymphocytes

In normal pulps, T lymphocytes are In normal pulps, T lymphocytes are found, but B lymphocytes are scarce.found, but B lymphocytes are scarce.

Dendritic cellsDendritic cells

Are found in and around the Are found in and around the odontoblast layer in nonerupted odontoblast layer in nonerupted teeth and in erupted teeth beneath teeth and in erupted teeth beneath the odontoblast layer.the odontoblast layer.

Same function as Langerhans’ cells Same function as Langerhans’ cells found in epithelium found in epithelium

Matrix and ground Matrix and ground substancesubstance

The extracellular compartment of The extracellular compartment of the pulp or matrix, consist of the pulp or matrix, consist of collagen fibers and ground collagen fibers and ground substance.substance.

The fibers are principally type I and The fibers are principally type I and type III collagen.type III collagen.

In young pulps, single fibrils of In young pulps, single fibrils of collagen are found scattered collagen are found scattered between the pulp cell.between the pulp cell.

Innervation of dentin-pulp Innervation of dentin-pulp complexcomplex

The dental pulp is innervated richly.The dental pulp is innervated richly. Nerves enter the pulp through the Nerves enter the pulp through the

apical foramen, along with the apical foramen, along with the afferent blood vessels, and together afferent blood vessels, and together with the neurovascular bundles.with the neurovascular bundles.

Dentin sensitivityDentin sensitivity

On of the unusual features of the On of the unusual features of the pulp-dentin complex is the pulp-dentin complex is the sensitivity. sensitivity.

The extreme sensitivity of this The extreme sensitivity of this complex is difficult to explain, complex is difficult to explain, because this characteristics provides because this characteristics provides apparent evolutionary benefit.apparent evolutionary benefit.

Pulp stonesPulp stones

Pulp stone, or denticles, frequently Pulp stone, or denticles, frequently found in pulp tissuefound in pulp tissue

They are discrete calcified masses They are discrete calcified masses calcium-phosphorus rations calcium-phosphorus rations comparable to that of dentin.comparable to that of dentin.

May contain tubules and may be May contain tubules and may be surrounded by cells resembling surrounded by cells resembling odontoblast.odontoblast.