1. Priya S. Chand MSD pchand@umaryland.edu

2. What does an Endodontist care about pulp histology ?

6. Origin of the Pulp Condensed Ectomesenchyme Dental Papilla Influence of Internal Dental Epithelium Dentin Effects Enamel Formation

7. Pulp Chamber Pulp Horn Orifice

8. Coronal Apical

11. Apical Foramen and Constriction

12.  Pulp Horns  Apical Foramen  Cemento-Dentinal Junction  Lateral and Accessory Canals

13. Pulp n Function : –Production of Dentin –Maintenance of Dentin

14.  Dentin  Predentin  Odontoblasts  Subodontoblastic plexus of Raschkow  Cell free zone  Cell rich zone  Pulp proper

15. Pulp Organization –Odontoblastic Zone –Cell-Free Zone (Weil) –Cell-Rich Zone –Pulp Core

20. Endodontics, Ingle’s, 2002

22.  Odontoblast  Fibroblast  Undifferentiated mesenchymal Cell  Macrophage  Dendritic Cell  Lymphocyte

24.  Most Distinctive Cell  Location:  Size Gradient:

25.  59K to 76K / mm 2 (Coronal)  Intercellular Junctions:  Gap Junctions  Tight Junctions  Adhesion Belts  Desmosome-like

26.  Devoid of Major Organelles  Occasional Mitochondria (Pre- Dentin)  OB- Equipped for Exo/Endocytosis

27.  Most Common Cell  Cell-Rich Zone  Pulp Core  Histology- Active vs. Resting  Functions:  Form Pulp Matrix  Maintain Pulp Matrix  Capable of Synthesizing, Ingesting  & Degrading Collagen Functions:

28.  Polymorphic and highly motile.  Tendency to Central Location  Function: Scavenge Dead Cells  Presence Implies FB Turnover  Class II MHC Positive  Histology:  Large, Oval or Spindle-Shaped Nucleus  Dark-Staining Nucleus  Clear Cytoplasmic Areas

29.  Location: Below OB Zone  Cell Processes between odontoblasts  Function: Immunosurveillance  Recognize, Capture Foreign Ag  Non-Phagocytic  Increased in Carious Teeth  Class II MHC Positive

31.  T- Lymphocytes  Present in Normal Pulp  B- Lymphocytes  Present in Inflamed Pulp

33.  Fibers  Type I collagen (predominant in dentin) produced by odontoblasts  Type I & III (in pulp, ratio 55:45) produced by pulp fibroblasts  Type V, small amount in pulp  Reticular fibers  Aging, increase in collagen  Apical portion has more collagen then coronal.

34.  Ground substance  Similar to other soft connective tissue  Glycosaminoglycans,  glycoproteins,  Water in the form of sol-gel.

35.  Apical Foramen Area  Arteriolar Size (  150  m)  Afferent & Efferent Vessels  Arterioles, Venules, Lymphatics  Radicular Pulp  Central Location, Larger Lumen  Coronal Pulp  Extensive Vascular Capillary Network

36. Vasculature of the Pulp Muscular Walls Smaller Lumen Arteriole Thinner Walls Larger Lumen Venule Pulpal Vessels Have Thinner Walls Owing to “Low-Compliance” Environment

37. Vasculature of the Pulp Nerves Venules Arterioles Lymphatics ? ? ? ?

38. P & P Endodontics, 2002

39. Endodontics, Ingle’s, 2002

40.  Sensory axons  myelinated  A  (1-6  m), predominant  A  (6-12  m), small percentage  unmyelinated  A  and A  after branching off  C fibers (< 1  m), mainly in pulp core

41. Branching of nerve bundles as they approach the subodontoblastic region (plexus of Raschkow) Endodontics, Ingle’s, 2002

42.  Sensory  Afferents of CN V  Transmit Pulpal Sensation  Effectors on Arterioles, Capillaries, Veins  CGRP  Vasodilation  Substance P  Plasma Extravasation Sympathetic  Superior Cervical Ganglion  Control Arteriolar Smooth Muscle

43.  Myelinated  Mostly A  fibers; Larger; Faster  Mediate Sharp, Localized Pain  Non-Myelinated  C fibers; Smaller; Slower  Myelin Sheath Reduction Coronally

44.  Sensory  Afferents of CN V  Transmit Pulpal Sensation  Effectors on Arterioles, Capillaries, Veins  CGRP  Vasodilation  Substance P  Plasma Extravasation  Sympathetic  Superior Cervical Ganglion  Control Arteriolar Smooth Muscle

45. Suda et al, 1997

46. Lymph Drainage and Lymphatic Vessels P & P Endodontics, 2002

47. Lymphatic capillary arising and collecting from within the odontoblast- subodontoblast region Endodontics, Ingle’s, 2002

48. Hard tissue apposition in pulp space Endodontics, Ingle’s, 2002

49.  Significance:   Overall # of Pulp Cells   Reparative Potential  NOT a Cause of Pain  Interference with RCT

50. Uninflamed pulp. Typical pattern of calcifications Endodontics, Ingle’s, 2002

51. Pulp Stone Endodontics, Ingle’s, 2002

54. n Protection of Pulp –Intra-Tubular Mineralization (sclerosis)  –Reduced Thermal Sensitivity –Impaired Bacterial Penetration

55.  Free denticles located free in the pulp  Attached denticles attached to the wall of pulp chamber (protruding into the pulp)  Interstitial denticles wholly within wall of pulp chamber  True denticles ( formed by odontoblasts ) rare and when present, located in radicular pulp False denticles Do not posess odontoblasts.

56.  Age Changes Affect Response  Stimulated “Age Changes”

57.   in Myelinated & Unmyelinated Nn  Age-Related  in Sensitivity  Dystrophic Calcification  If Large, “False” Pulp Stone  Contributes to Reduced Vascularity “ Diffuse” Calcification

58. YoungerOlder Vascularity “R” Us  Collagen,  Flow

59.  Accelerated Dentin Deposition

60. Calcified Canals

61. Age Changes More Fibrous, Less Cellular Endodontics, Ingle’s, 2002

62. Age Changes In Blood Vessels Endodontics, Ingle’s, 2002

63. DiseasedNormalDiseased Calcifying Human Dental Pulps

64.  Seltzer and Bender’s Dental Pulp, by Hargreaves & Goodis 2002  Essentials of Oral Histology and Embryology, by Leslie P Gartner 1999