Dental pulp

dental pulp

1. DENTAL PULP DEPARTMENT OF PAEDODONTICS AND PREVENTIVE DENTISTRY C.K.S TEJA INSTITUTE OF DENTAL SCIENCES,TIRUPATI PREPARED BY : L. MAHESHWAR REDDY 1 ST YEAR M.D.S

2. CONTENTS Introduction Embryology Anatomy Structural organization of pulp Cells of pulp Extra-cellular matrix Circulation of pulp Metabolism of pulp Innervation of pulp Functions of pulp Pulp of deciduous teeth Age changes Clinical considerations Recent advances Conclusion References

3. INTRODUCTION DEFINITION: According to Cohen - the pulp is a soft tissue of mesenchymal origin residing within the pulp chamber and root canal of teeth. SALIENT FEATURES

4. Maxillary (Cubic Centimeter) Mandibular (Cubic Centimeter) Central Incisor 0.012 0.006 Lateral Incisor 0.011 0.007 Canine 0.015 0.014 First Premolar 0.018 0.015 Second Premolar 0.017 0.015 First Molar 0.068 0.053 Second Molar 0.044 0.032 Third Molar 0.023 0.031

5. DEVELOPMENT

6. ANATOMY OF PULP CORONAL PULP It is the pulp occupying the pulp chamber of the crown of the tooth RADICULAR PULP It is the pulp occupying the pulp canals of the root of the tooth

7. APICAL FORAMEN ACCESSORY CANAL

8. Structural Organization of pulp

9. Dentin Predentin Odontoblasts layer Cell free zone Cell rich zone Pulp core

10. Histology of pulp Morphologic zones of pulp- ODONTOBLAST LAYER CELL-POOR ZONE CELL-RICH ZONE PULP PROPER

11. Odontoblastic layer CELL FREE ZONE CELL RICH ZONE

12. PULP CORE The pulp proper is the central mass of the pulp It contains the larger blood vessels and nerves. The connective tissue cells in this zone are fibroblasts, or pulpal cells.

13. Histological Structures of the Pulp The dental pulp is formed of specialize loose connective tissue contain : 1) Cellular elements : a. Formative cells : Odontoblast , Fibroblast . b. Progenitor cells : Undifferentiated mesenchymal cells c. Defensive cells : Macrophages, neutrophils , eosinophils , basophils , mast cells , plasma cells and Lymphocytes.

14. 2) Fibrillar elements : a. collagen bundles b. fine collagen fiber 3) Ground substance: Act as a medium to transport nutrients to cells and metabolites of the cell to the blood vessels. 4) Neurovascular elements : Blood vessels, nerves, lymph vessels

15. ODONTOBLAST Second most common cells in the pulp . Dentin Pulp Odontoblast process Odontoblast cells

16. ODONTOBLASTIC PROCESS JUNCTIONAL COMPLEXES

17. b- Fibroblasts

18. UNDIFFERENTIATED MESENCHYME

19. IMMUNOCOMPETENT CELLS They play a major role in local inflammation and immunity. They are recruited from blood stream & remain as transient inhabitants in pulp These cells are - Lymhpocytes -Macrophages - Dendritic cells -Mast cells

20. A- Histiocyte ( macrophage ) : B-Plasma cells:

21. LYMPHOCYTES IN PULP DENDRITIC CELLS Eosinophils

22. MAST CELLS

23. EXTRA CELLULAR MATRIX FIBRE GROUND SUBSTANCE COLLAGEN ELASTIN FIBRONECTIN LAMILIN GAG PR OTEOGLYCAN

24. Collagen fibers

25. Von kroff fibres Collagen has been described as having a unique arrangement in the peripheral pulp, these bundles of collagen are called Von kroff bundles.

26. GROUND SUBSTANCE It is a structureless mass, gel-like consistency, makes up the bulk of the pulp Consists complexes of proteins, carbohydrate and water. Broadly classified as a.Proteoglycans - Functions of GAG- 1.Water retention 2. Ion binding & electrolyte distribution during mineralization ( Bowness 1968). b. Glycoproteins Water- 90%

27. Maintain tissue’s physical properties and integrity Control of growth and development and repairs Control of cell migration Control of diffusion of macromolecules FUNCTIONS OF PULPAL EXTRACELLULAR MATRIX

28. CIRCULATION OF THE PULP Systemic circulation:- Pulp organ is extensively vascularised with blood vessels arising from internal maxillary artery Internal maxillary artery Mandibuar artery pterygoid artery Pteygo -palatine artery Inferior alveolar artery infraorbital artery posterior superior alveolar artery Dental incisive mental anterior superior alveolar branch artery artery   molars, incisors lower lip incisors, bicuspids molars, bicuspids premolars

29. Microcirculation: Arterioles (50 μ diameter) ▼ Terminal arterioles ▼ Precapillaries ▼ Metarterioles ▼ Capillaries (8 μ )  

30. SEM shows extensive arborization of capillaries from the metarterioles

31. CAPILLARIES : Venules LYMPHATICS

32. REGULATION OF PULPAL BLOOD FLOW Neuronal regulation a. Sympathetic fibers b. Parasympathetic fibers c. Peptidergic afferent fibers Endocrine & paracrine regulation

33. INNERVATION Principle role is to help in conscious recognition of irritants to the pulp, which gives the opportunity to have the problem corrected before irreversible effects can occur Nerve fibers, mylinated & unmyelinated , enter the tooth through the apical foramen Dental pulp Sensory afferent fibers Motor nerves Branches of maxillary & mandibular divisions of trigeminal nerve. Sympathetic division of autonomic nervous system

34. Plexus of Rashkow

35. Sympathetic Innervation Sympathetic nerve fibers forming plexus around arterioles

36. Neuropeptides They are proteins that have been associated with central & peripheral nervous system. Following are the neuropeptides demonstrated in nerves of dental pulp: Substance p 5 hydroxy tryptamine Vasoactive intestinal peptide Prostraglandin Somatostation Acetylcholine Norepiepheine

37. Nerve Plexus of Raschkow Sensory nerve fibers that originate from inferior and superior alveolar nerves innervate the odontoblastic layer of the pulp cavity. These nerves enter the tooth through the apical foramen as myelinated nerve bundles. They branch to form the subodontoblastic nerve plexus of Raschkow which is separated from the odontoblasts by a cell-free zone of Weil. In addition to the sensory nerves, sympathetic nerve bundles also enter the tooth to innervate blood vessels.

38. A, Odontoblasts; B, Cell-free zone of Weil; C, Nerve plexus of Raschkow

39. A-delta fibers Conduction velocity 2-30 m/s Lower threshold Involved in fast, sharp pain Stimulated by hydrodynamic stimuli Sensitive to ischemia Sharp pain C fibers Conduction velocity 0-2 m/s Higher threshold Involved in slow, dull pain Stimulated by direct pulp damage Sensitive to anesthetic s Dull pain A-beta fibers Conduction velocity 30-70 m/s Very low threshold , non-noxious sensation 4 % of myelinated fibers in pulp Functions not fully known Non-myelinated sympathetic fibers Conduction velocity 0-2 m/s Post- ganglionic fibers of superior cervical ganglion Vasoconstriction & Vasodilation.

40. Nerves in pulp

41. Dentin pulp complex Dentin the most voluminous at mineralized connective tissue of the tooth forms the hard tissue portion of the dentin pulp complex where as dental pulp is a living soft connective tissue maintains the vitality of the dentin ( Linde and Goldberg 1993, Torneck 1994) Dentin contains multiple closely packed dentinal tubules in which the dentnal fluid and the cytoplasmic process of the cells that have formed the dentin, the odontblast are located( Torneck 1994) The unity of dentin and pulp is responsible for formation and protection of the tooth

42. FUNCTIONS OF DENTAL PULP INDUCTIVE FORMATIVE NUTRITIVE PROTECTIVE DEFENSE

43. PULP OF DECIDUOUS TEETH Anatomical differences- Dimensions Pulp chamber Pulp horns Cervical constrictions Root canals Accesory canals Apical foramen Histological differences- Degree of cellularity Vascularity Innervation

44. AGE CHANGES Various age changes in pulp are- - Dimensional changes - Cellular changes - Pulpal fibrosis - Calcifications - Changes in vascularity

45. Age changes in the pulp The size of the pulp The apical foramen The cellular elements The bl. vessels & n. Vitality Reticular atrophy: The total affect is the production of a lessened vitality of the pulp tissue and a lessened response to stimulation. decreased

46. Pulpal fibrosis

47. PULP CALCIFICATIONS It is a common occurrence with incidence of 50% of all teeth Size may range from microscopic particle to stones that may occlude the pulp chamber Composed of carbonated hydroxyapitite crystals Pulp calcification may be- -Pulp stones True pulp stones false pulp stones -Diffuse calcifications - Calcific Metamorphosis

48. Sundell Schematic Presentation Local Metabolic Dysfunction Trauma Hyalinization of injured cell Vascular Damage Thrombosis Vessel Wall Damage Fibrosis Mineralization Growth Pulp Stones

49. Denticles True denticle - False denticle -

50. attached free Attached denticle Free denticle

51. Diffuse Calcification

52. Calcific Metamorphosis Luxation of teeth as a result of trauma may result in calcific metamorphosis Usually results in partial or complete radiographic obliteration of the pup chamber Resembles cementum or bone on dentinal walls Teeth may present with a yellowish hue

53. Decrease in quality of blood vessels Blood vessels:- Aging has an adverse effect on the number & quality of blood vessels supplying the dental pulp (Benefit 1965) The arterioles in the older pulp exhibited hyperplasia of the intima & dystrophic changes in the media & adventitia.

54. CLINICAL CONSIDERATIONS Anatomical considerations Effect of dental materials on pulp Effect of Operative Procedures

55. EFFECT OF DENTAL MATERIALS ON PULP Amalgam corrosion products inhibit cell growth high thermal conductivity Glass ionomers well tolerated by pulp RMGI used for direct pulp capping Zinc Oxide Eugenol has an anti-bacterial and anodyne effect The sedative effects are due to eugenol ability to block / reduce the nerve impulse activity higher concentrations leads to chronic inflammation, thrombosis of vessels

56. Formocresol High degree of diffusion causes a chronic inflammation of the pulp .Mutagenic and carcinogenic Calcium hydroxide induces dentin bridge formation when used for direct pulp capping Mineral trioxide aggregate Superior to calcium hydroxide as a direct pulp capping agent

57. Zinc Phosphate Strong to moderate cyto -toxic reactions is due to leeching of zinc ions and low Ph Resin adhesive systems The formation of hybrid layer secures the enamel-resin interface with a continuous seal which acts as a biometic barrier Dentin bonding agents Monomer molecules reaching the pulp can irritate the pulp causing inflammation

58. Acid etching – Etching apparently increases the pulpal inflammation because it removes the debris that accumulate over the dentinal tubules when they are cut thereby facilitating the penetration of irritants into dentinal tubules EFFECT OF OPERATIVE PROCEDURES Effects of tooth preparation Pressure and Frictional heat Desiccation Exposure of dentinal tubules Direct damage to odontoblast process

59. CAVITY DEPTH 1mm – Shields Pulp 0.5- 0.25mm – Tertiary Reactive Dentin 0.25mm> ~ Odontoblasts die & Reperative dentin is formed very fast.

60. CAVITY DRYING 61

61. PULPAL PATHOLOGIES Reversible pulpitis Irreversible pulpitis Chorinic hyperplastic pulpitis Internal resorption External resorption

62. Irreversible pulpitis Chorinic hyperplastic pulpitis

63. External Resorption Internal resorption -

64. Recent advances Pulpal regeneration- This exciting new era was found by Urist with the introduction of bone morphogenic protein In pulpal regeneration the tissue would be isolated from noxious restorative material in the chamber, thereby diminishing the chances of resorption . BMP’s are osteogenic proteins implicated in cell differentiation, tissue morphogenesis, regeneration and repair.

65. Stem cells Dental pulp stem cells are multipotent stem cells that have a potential to differntiate into a variety of cell types. Historically, dental stem cells were first isolated by “ Gronthos ” and co-workers from the dental pulp. Animal studies have shown the great potential of DPSCs for repair and regeneration of various tissues, such as , heart, muscles , and teeth Clinically a bio- teeth made from autogenous DPSC,s should be the best choice for clinical tooth reconstruction

66. There are two widely used methods for the isolation of dental pulp stem cells: the explant method (DPSC-OG) and the enzymatic digestion method of the pulp tissue (DPSC-EZ) .

67. It has been demonstrated that the outgrowth method allows DPSCs to differentiate into skeletal muscle fibres. Markers expressed by DPSCs are CD29 and CD44,CD34 as well as CD73 and CD105 and CD 117. This population has great self-expansion and osteogenic differentiation capabilities and produces a living autologous fibrous bone (LAB) tissue in vitro and bone tissue when implanted in mice.

68. Conclusion we, as dental physicians, provide the highest level of technical and scientific accuracy and artistic flair in the holistic well being of the tooth organ and in turn fulfill the aspiration of those individuals who place in us their unwavering trust - our patients.

69. Refences Dental pulp; Seltzer and bender; 3 rd edition y ; Oral Histology; Tencate ; 5 th Edn Oral Histology & Embryology; Orban 11 th Edn Pathways of Pulp; Cohen; 8 th Edn Endodontics ; Ingle; 5 th Edn Textbook Of pedodontics ; Shobha Tandon

70. ANCA VIŢALARIU1), IRINA-DRAGA CĂRUNTU2) Department of Oral Rehabilitation, Faculty of Dentistry, “Gr. T. Popa ” University of Medicine and Pharmacy, Iassy 2) Department of Oral Biology, Faculty of Dentistry, “Gr. T. Popa ” University of Medicine and Pharmacy, Iassy-2005 Review of Dental pulp stem cells : State of the art and suggestions for a true translation of research into therapy Marcella La Noce a , Francesca Paino a , Anna Spina a , Pasqualina Naddeo a , Roberta Montella a , Vincenzo Desiderio a , Alfredo De Rosa b , Gianpaolo Papaccio a, *, Virginia Tirino a, *, Luigi Laino c-2014