This document discusses regressive changes that occur in the pulp and dentin as part of the normal aging process. It begins by covering theories of aging and the roles of oxidative stress and telomeres. It then classifies different regressive changes that can occur in enamel, dentin, pulp, cementum, and resorption of teeth. The document goes on to discuss specific regressive changes in detail, including changes to odontoblasts, the extracellular matrix, dentinogenesis, and degenerative changes in the pulp like reticulation, calcification, and changes to blood vessels and nerves. It concludes by discussing endodontic implications of these regressive changes.

1. Sandakphu, Darjeeling, west Bengal, India

2. Regressive changes of
PULP
Presented by
Dr Abhisek Guria
2nd year MDS
Dept of Conservative dentistry
& Endodontics
SHDCH, Hassan

3. Contents
• Introduction
• Aging
– biologic theories of senescence
• programmed theory
• stochastic theory
– roles of oxidative stress
– Telomeres
• Classification
• Atrition, abrasion, erosion & abfraction
• Regressive changes of pulpo dentine cmplex
• Odontoblast & aging
• effect of aging of the extracellular matrix
• Dentinogenesis & aging
• Intratubular and intertubular dentin
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4. • Dentinal sclerosis
• Dead tracts
• Secondary dentine
• Tartiary dentine
• DEGENERATIVE CHANGES OF PULP
• Characteristics
• Histologic and histomorphologic changes
• Biologic consideration
• Blood vessels
• Sensory nerves
• Reticular atrophy of pulp
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5. • Pulp calcification
– Etiology
– Associated with
– Classification
– Characteristics
• Endodontic implication
– Response to pulp testing
– Radiographic signs of aging
– Calcification of canal
• Management of calcified canal
– Orifice Recognition
– Biomechanical Preparation
– Chelating Agents-Is There Any Role ?
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6. • Resorption of tooth
• Internal resorption
– Inflammatory resorption
– Replacement or metaplastic resorption
• External resorption
– Surface
– Inflammatory
– Replacement
– Spontaneous ankylotic
– Multiple site of ankylotic or infected
• Conclusion
• References
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7. Introduction
• They are not developmental abnormalities or
inflammatory lesions.
• No bacterial involvement
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8. • Results from general aging process
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9. aging vs disease
• Age changes occur in every multicellular animal
that reaches a certain size when reproductively
mature.
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10. 11/13/2018 regressive changes of pulp 10
Biologic theories of replicative
senescence
Roles of oxidative stress
Telomeres
• Aging in a particular tissue or area of the body is
based on

11. Theories of senescence
• Programmed theory - aging is regulated by
biologic clocks operating throughout human
lifetimes
• Stochastic theory - environmental conditions
impact living organisms, causing cumulative
damage to DNA
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12. Oxidative stress
• Accumulation of ROS inside of cells as a
function of cellular activity
• Cellular damage caused by ROS
• Impairs physiologic functions,
• Increases the risk of tissue disease
• Reduces life span
(Lee and Wei)
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13. Telomeres
• limited capacity of normal cells to divide is an
expression of aging, leading to the determination
of the longevity of the organism.
• At a certain shorter length, telomeres signal a
cell to stop dividing
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Hayflick and Moorhead

14. classification
Enamel
• Attrition
• Abrasion
• Erosion
• Abfraction
Dentin
• Dentinal sclerosis
• Dead tracts
• Secondary dentine
Pulp
• Reticular atrophy of
pulp
• Pulp calcifications
Resorption of teeth
• External
• Internal
Cementum
• Hypercementosis
• Cementicles
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15. Attrition
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16. Abrasion
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17. Erosion
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18. abfraction
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19. REGRESSIVE CHANGES OF
PULPO-DENTINE
COMPLEX
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20. 11/13/2018 regressive changes of pulp 20

21. Structural organization of pulp
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22. Odontoblasts and aging
• An SEM analysis of cell processes in
caries-free and attrition-free premolars
in 14- to 16-year-old and 59- to 72-
year-old patients.
• In the younger pulps, the odontoblast
processes extended into the dentinal
tubules, often reaching the DEJ.
• in the older pulps, fewer processes
were found in sclerotic dentin and they
never extended close to the DEJ.
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23. • Odontoblasts are actively secreting during
primary dentinogenesis
• become less active during secondary
dentinogenesis.
• The actual time of switching from the
primary stage to the secondary stage is
still not well defined.
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24. • Expression of DMP-1 and osteocalcin genes
was upregulated in the mature odontoblasts
• Expression of type I collagen, DSPP, TGF-β1
receptor genes was downregulated
• Some author suggested consider young and old
(odontocytes) odontoblasts as two different cell
types
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25. • A Japanese group highlighted differential
expression of cbfa1, VEGF, and HSP-27 mRNAs
in young and old odontoblasts in rat teeth.
• Expression of CBFA 1 mRNA was higher in
young rats
• While expression of VEGF and HSP-27 mRNAs
was higher in the adults.
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26. effect of aging of the extracellular matrix on cells
• Exposed aged pulp cells to juvenile-conditioned medium
and juvenile cells to adult-conditioned medium.
• Adult pulp cells cultured with juvenile conditioned
medium showed enhanced proliferation but a reduced
ability to differentiate.
• In contrast, young cells cultured with adult-conditioned
medium changed their behavior and proliferated and
differentiated as adult cells
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27. Dentinogenesis
• In erupted teeth secondary dentin formation from coronal to apical
direction. In impacted teeth reverse direction
• Constriction of chamber occurs in mesiodistal direction.
• Slower in women than in men.
One study evaluated ground sections from 273 maxillary central
incisors
• Young teeth (6 to 11 years old) demonstrated metamorphosed
(transparent) tracts at the incisal and cervical areas.
• Teenagers (11 to 15 years old) showed initial signs of irregular
dentin formation (fewer tubules)
• In older individuals as dentin was deposited on the lingual walls of
the coronal samples.
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28. • In a study with monkeys, restorative
procedures evoked a fourfold greater
rate of tertiary dentin formation than
secondary dentin formation
• Capacity to mineralize predentin ( MMP
gelatinase A) may decrease with age
• So, teeth of elderly individuals less
protected from external stimuli.
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29. Intratubular and intertubular dentin formation
• Peritubular and intratubular dentin forms
throughout life
• Intratubular dentin formation sometimes leading
to full occlusion or total sclerosis of the dentinal
tubules.
• Contains rhomboidal whitlokite
• From the apical third toward the cervical area
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30. Dentinal sclerosis
• Syn : Transparent dentine
Causes
• calcification of dentinal tubules
• injury to the dentinal tubules
• DC
• Abrasion
• Aging process
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Source of Ca
• Dental lymph
• saliva

31. 11/13/2018 regressive changes of pulp 31
Sclerosed dentin (1)
Dead tracts (2)
secondary dentin (3)

32. appearance
• Translucent zone in transmitted light
• Seen in Apical 3rd of root
• In crown- midway b/w DEJ and pulp
• Dentin underlying cavity
• More calcified than reparative dentin.
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33. • Result:
• Decreased conductivity of odontoblastic
process.
• Slows the advancing carious process.
• Dye cant penetrate through the sclerotic
dentine
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34. Dead tracts
• Dead tracts are empty dentinal
tubules filled with air.
• Formed due to degeneration of
odontoblastic process
• These appear dark in under
transmitted light
• white under reflected light.
• develop in the region of cusp or
incisal edge
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35. Secondary dentine
Physiological secondary
dentin :
• Formed after root completion
and eruption of teeth
• It is regular, uniform
• laid down throughout the life
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36. Tertiary dentin
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Reactionary Reparative
Stimulus for
formation
Mild Aggressive
Formative cell
Surviving post mitotic
odontoblast
New odontoblast from
progenitor cell
Structure
Physiologic dentin
Change in direction of
tubules
Heterogenus
Tubular – osteodentin
Disorganized -
fibrodentin

37. CLINICAL FEATURES:
• Decrease in the
sensitivity
• Forms additional
insulating layer in tooth.
• Seen in in pulp horn
areas
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Change in the direction of the dentinal
tubules as they pass from primary (b) to
secondary ( a) dentin

38. DEGENERATIVE CHANGES OF
PULP
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39. Functional - occurring through use
( “wear and tear”)
Geriatric - due to factors intrinsic to the
normal aging process
Characteristic changes with aging in fully
formed human teeth were first described by
Lacasagne in 1889 and scientifically
confirmed in 1950
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40. Characteristics
• Number of cells in the pulp diminishes
• Alters the dentinogenic activity of the surviving
odontoblasts
• Progressive reduction of pulp space
• IgG levels diminish
• Increase in fibrosis and levels of calcification
• Increase collagen
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41. Histologic and histomorphologic changes
• Levels and distributions of the cytoskeletal proteins actin,
cytokeratin, and vimentin diminish
• Reductions in odontoblast processes
• Capillaries form a dense plexus beneath the predentin
• Loss of fenestrations in the capillaries
• Reduction of odontoblast function, become smaller and
flattened
• Increased calcification of the extracellular matrix,
• Decreased numbers of blood vessels and nerves,
• Fusion of von Korff fibers in the odontoblastic area
11/13/2018 regressive changes of pulp 41
Bernick and Nedelman

42. • Increase in calcium
• Decrease in levels of dihydroxy-lysin-on-leucine
(DHLNL)
•
• Star-shaped fibroblasts are seen in the pulp of young
individuals, yet they are diminished in size and number
• Amount of predentin are also diminished
• Genes encoding specific markers such as DSPP,
ameloblastin, or osteonectin are higher in the older
dental pulp.11/13/2018 regressive changes of pulp 42

43. • Aim: Evaluation of matrix
components in 332 human teeth in
three age groups (10 to 30 years,
31 to 51 years, and 52 to 72 years).
Results:
• Collagen types I, IIl, V, and VI are
present at all ages.
• With advancing age type I collagen
increase
• Types III, V, and VI collagen
disappear or are replaced by thick
fiber bundles
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44. Biologic consideration
• connexin 43 was abundantly expressed in young adult
dental pulps
• dramatically decreased in aged dental pulps
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45. Blood vessel
• The number of vessels diminishes and
the vascular plexus becomes reduced
• intimal hyperplasia of arterioles,
narrowed vessel lumens
• calcification of the vessel wall
• Vessel degeneration near the incisal
end of the pulp.
• Loss of fenestration in the capillaries
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46. • As secondary dentin formation continued, causing
narrowing and elimination of medium-sized vessels and
capillaries
• decreases in both ALP and ATPase enzymes ,
accompanied by a reduction in metabolic activity of the
pulp
• In the endothelial cell cytoplasm of older pulpal vessels,
pinocytotic vesicles, microvesicles, and microfilaments
were more numerous
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47. Sensory nerves
• Decrease in number of nociceptors
• calcification of the endoneurium and
perineurium and ultimately the nerve
proper
• loss of the plexus of nerve fibers
• number of myelinated fibers
• increased threshold of response to
stimulation
• Two neuropeptides CGRP and
substance P also diminish
• loss of small Aδ fibers and unmyelinated
C fibers
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48. PULP
CALCIFICATION
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49. Etiology
11/13/2018 49
Local metabolic dysfunction Trauma
Hyalinization of injured cells
Vascular damage
Fibrosis
Mineralization (Nidus formation)
Growth with time
Pulp stone

50. Associated with
• Dentine dysplasia,
• Dentinogenesis imperfecta
• Van der Woude syndrome
(Kantaputra et al. 2002)
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51. classification
• True
• Made of dentine
• lined by odontoblasts.
• False
• Formed from degenerating
cells
• which mineralize.
• Free
• Stone not related to pulp
space wall
• surrounded by soft tissue.
• Adherent
• Stone attached to wall of
• pulp space
• not fully enclosed by dentine.
• Embedded
• Stone enclosed within canal
wall
11/13/2018 regressive changes of pulp 51

52. • Denticle
• An alternative term for pulp stone,
• more usually a calcification filled with epithelial remnants
• surrounded by odontoblasts.
• Fibrodentine
• Material produced by fibroblast-like cells against dentine
• prior to differentiation of a new generation of odontoblast-like
cells.
• Dystrophic calcification
• Inappropriate biomineralization of the pulp in the absence of
mineral imbalance.
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53. characteristics
• In underdeveloped root - thimble shape with the open
end facing apically
• in primary teeth
• 6.7% - had pulp stones
• 11.7% having diffuse calcification
• some pain of an idiopathic nature may be caused by pulp
stones
(Seltzer & Bender 1984)
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54. ENDODONTIC
IMPLICATION
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55. Response to pulp testing
• Reduced responsiveness to thermal testing in
the elderly
• Decrease in number of fast-conducting afferents
and impaired nerve activation
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56. • change of permeability disturbs the homeostasis and can
lead to pulpal disease, notably inflammation
• diminution of permeability can be considered an
advantage in preventing the movement of bacteria and
toxins into the tubules,
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57. • the reduction in size of the tubules - bonding systems
require the penetration of the resin to create tags inside
the dentin thickness
• penetration and efficiency of disinfectant solutions are
more limited
• that biofilm is more difficult to eliminate from mature
teeth
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58. Radiographic signs of aging
• Do not reveal the actual types of dentin present
in calcified root canal systems
• they provide a measure of age-related changes
occurring in root canal systems due to
secondary or tertiary dentin formation.
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59. Calcification of canal
• Certain drugs such as calcium hydroxide and
corticosteroids, when placed on the dentin after cavity
preparation cause sclerosis.
• In upper anterior teeth deposition is more on the lingual
wall
11/13/2018 regressive changes of pulp 59Seltzer & Bender
Deciduous Permanent
Secondary dentin 4 microns/ day
reparative dentin 2.8 microns 1.5 microns
Schour et al

60. Management of calcified canal
• A) Orifice Recognition
• The LN bur (Caulk/ Denstply, Tulsa, OK, USA)
• Mueller bur (Brasseler, Savannah, GA, USA)
• DG-16 explorer
• thin ultrasonic tips
11/13/2018 regressive changes of pulp 60

61. • No. 8 or No. 10 K –file is placed
into the orifice, to negotiate the
canal.
• Or use instruments with reduced
flute, such as a Canal Pathfinder
(JS Dental, Ridgefield. Conn.)
• or instruments with greater shaft
strength such as the Pathfinder
CS ( Kerr Manufacturing Co.)
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62. • The uncovering of the floor of the
pulp chamber can be
accomplished with the help of the
CPR 2D or BUC 1 tips.
• The pulp stones sometimes can be
vibrated or teased out by these tips
• Grind the floor until the dark-
colored dentine becomes visible.
11/13/2018 regressive changes of pulp 62

63. B) Biomechanical Preparation
• Coronal flaring in a crown- down fashion is
preferred.
• Incremental instrumentation is achieved by
cutting off a portion of the file tip, thus making it
slightly wider in diameter.
11/13/2018 regressive changes of pulp 63

64. C) Chelating Agents-Is There Any Role ?
• liquid EDTA solution be introduced
into the pulp chamber (pipette, cotton
pellet) to identify the entrance to
calcified canals
• Within narrow canals ultrasonics
should ideally be coupled with the
dissolving action of sodium
hypochlorite to produce a synergistic
effect
11/13/2018 regressive changes of pulp 64
(Cunningham & Balekjian 1980)

65. • Calcified teeth that were not treated endodontically developed
radiographic or clinical symptoms in upto 16% of the cases.
• Studies of the success and failure of conventional endodontic
therapy reported failure rates of 10% to 19%.
• it appears that a calcified tooth treated endodontically
would have no better chance of success than if it were
left alone
11/13/2018 regressive changes of pulp 65
Smith et al

66. Resorption of tooth
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67. INTERNAL RESORPTION
• Synonym
• Chronic perforating hyperplasia of pulp
• Internal granuloma
• Odontoclastoma
• Pink tooth of mummery
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68. • begins centrally
• Two main patterns
11/13/2018 regressive changes of pulp 68
Inflammatory
resorption
Replacement or
metaplastic resorption

69. INFLAMMATORY RESORPTION
• Resorbed dentin is replaced
by inflamed granulation tissue.
• Site – cervical zone
• Resorption continues as long
as vital pulp remains
• Coronal pulp – necrotic and
apical pulp – vital
11/13/2018 regressive changes of pulp 69

70. • Appear as uniform , well
circumscribed symmetric
radiolucent enlargement in the
pulp chamber or canal
• When the root surface is
perforated, it is impossible to
determine whether the lesion began
externally or internally.
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71. REPLACEMENT RESORPTION
• Here portion of pulpal dentinal wall are resorbed and
replaced with bone or cementum like bone
• R/F :
• less radiolucent than the surrounding dentin.
• central zone appears partially obliterated.
• The outline of destruction is less defined than that
seen in inflammatory resorption.
11/13/2018 regressive changes of pulp 71

72. H/F
• Variable degree of resorption and proliferation of pulp
tissue filling the defect.
• Lacunae shows - odontoclasts or osteoclasts so called
as odontoclastoma.
• Ch. Inflammatory cells are present.
• Enamel is also resorbed
when the internal resorption
occurs in the crown portion.
11/13/2018 regressive changes of pulp 72

73. External resorption
• Etiology
• Periapical inflammation
• Reimplantation of teeth
• Tumors and cysts
• Excessive mechanical or occlusal forces
• Impaction of teeth
• Dental trauma
• Hormonal imbalance
• Intra coronal bleaching of pulp less teeth
• Local involvement of herpes zoster
• Paget's disease of bone
• PDL treatment
11/13/2018 regressive changes of pulp 73

74. Surface
Due to trauma
Inflamatory
Injury to PDL
Replacemen
t
In case of avulsion
Spontaneou
s ankylotic
infraocclusion
Multiple site of
ankylotic or
infected
11/13/2018 regressive changes of pulp 74

75. CONCLUSION
11/13/2018 regressive changes of pulp 75

76. References
1. Seltzer and bender's dental pulp – 2nd edition
2. Shafer’s textbook of oral pathology – 7th edition
3. Cohen's pathways of the pulp – 10th edition
4. Patterson SS & Mitchell DR. 1965. Calcific metamorphosis of the dental
pulp. Oral Surg Oral Med Oral Pathol, 20: 94–101.
5. Abdel Wahab MH, Kennedy JG (1986) Pulp stones as a cause of dental
pain: a case report. Journal of the Irish Dental Association 32, 19–21.
6. Gutmann J.L, Dumsha T.C, Lovdahl P.E, Hovland E.J. Problem Solving in
Endodontics: prevention, identification and management. Third
edition.1997 Mosby.
7. Andreasen FM, Yu Z, Thomsen BL & Andersen PK. 1987. Occurrence of
pulp canal obliteration after luxation injuries in the permanent
dentition.Endod Dent Traumatol, 3: 103–5.
8. Stenvik A, Mlor IA. Epithelial remnants and denticle formation in the
human dental pulp.ActaOdontolScand 1970;28:721-8.
11/13/2018 regressive changes of pulp 76

77. Thank
you!!!!!!