This document discusses pulpal reactions to various dental procedures and restorative materials. It covers reactions to caries, such as dentin sclerosis, tertiary dentin formation, and inflammatory responses. It also discusses reactions to local anesthetics, restorative procedures like cavity preparation and proximity to the pulp, and restorative materials like resin monomers, calcium hydroxide, and mineral trioxide aggregate. The document provides details on the protective and defensive mechanisms of the pulp as well as factors that influence pulpal irritation and viability.

2. PULPAL REACTIONS TO CARIES
AND DENTAL PROCEDURES
DR. SAJJAD HUSSAIN
DEMONSTRATOR PROSTHODONTICS
ISLAMIC INTERNATIONAL DENTAL COLLEGE
ISLAMABAD

3. TOPIC OUTLINE
• Pulpal Reactions to CARIES
• Pulpal Reactions to LOCAL ANESTHETICS
• Pulpal Reactions to RESTORATIVE PROCEDURES.
• Pulpal Reactions to RESTORATIVE MATERIALS.
• Pulpal Reactions to LASER PROCEDURES
• Pulpal Reactions to CAVITY PREPARATION USING AIR
ABRASION TECHNIQUES.
• Pulpal Reactions to VITAL BLEACHING TECHNIQUES.
• Pulpal Reactions to PERIODONTAL PROCEDURES.
• Pulpal Reactions to ORTHODONTIC SURGERY.
• Pulpal Reactions to IMPLANT PLACEMENT AND FUNCTION.

4. 1. PULPAL REACTION TO CARIES
Protective pulpal reactions include ;
1)- Decrease in dentin permeability.
2)- Tertiary dentin formation.
3)- Inflammatory and immune reactions.

5. PULPAL REACTION TO CARIES
1) - Decrease in dentin permeability:
It is the first & fastest defense to caries and is
called Dentin Sclerosis.
Increase the deposition of mineral crystals in
intratubular dentin → narrowing the dentinal
tubules → decreasing dentin permeability

6. PULPAL REACTION TO CARIES
1) - Decrease in dentin
permeability:
It is the first & fastest
defense to caries and is
called Dentin Sclerosis.
Increase the deposition
of mineral crystals in
intratubular dentin →
narrowing the dentinal
tubules → decreasing
dentin permeability

7. 1. PULPAL REACTION TO CARIES
2) - Tertiary dentin formation:
It is not the most effective pulpally mediated
defense.
MECHANISM; Acidic byproducts of the carious
process → degrade the dentin matrix
→liberate bioactive molecules sequestered
during dentinogenesis → reassume their role
in dentin formation.

8. PULPAL REACTION TO CARIES
• 2) - Tertiary dentin formation:

9. 1. PULPAL REACTION TO CARIES
2) - Tertiary dentin formation:
The resultant dentin character is highly
dependent on the stimulus.
In Mild Carious Lesion, odontoblasts are activated
to elaborate the organic matrix of dentin
(reactionary dentin), which is similar in
morphology to physiologic dentin and may only
be apparent due to a change in the direction of
the new dentinal tubules.

10. 1. PULPAL REACTION TO CARIES
2) - Tertiary dentin formation:
In Aggressive Carious Lesion, repopulation of
the disrupted odontoblast layer with
differentiating progenitors, forming reparative
dentin, its morphology can range from
organized tubular dentin to more disorganized
irregular fibrodentin.

11. 1. PULPAL REACTION TO CARIES
3) - INFLAMMATORY AND IMMUNE REACTIONS:
In the advancing infection front of the carious lesion,
multiple extrinsic and intrinsic factors that stimulate
inflammatory reactions,provides cellular and humoral
challenges to invading pathogens.
N.B: The buffering capacity of dentin fluid likely
attenuates the pH before it can directly effect a
deleterious response, except when the remaining
dentin thickness is minimal.

12. 1. PULPAL REACTION TO CARIES
3) - INFLAMMATORY AND IMMUNE REACTIONS:
The early inflammatory response can be seen
beneath non cavitated lesions and
noncoalesced pits and fissures.It is
characterized by the focal accumulation
of chronic inflammatory cells.

13. 1. PULPAL REACTION TO CARIES
3) - Inflammatory and immune reactions:
It is mediated;
Initially by odontoblasts; the most peripheral
cell in the pulp, and encounter foreign
antigens first.
& later by dendritic cells, which are
responsible for antigen presentation and
stimulation of T- lymphocytes.

14. 1. PULPAL REACTION TO CARIES
3) - Inflammatory and immune reactions:
Two distinct populations of dendritic cells:
•CD11c+ found in the pulp/dentin border and
subjacent to pits and fissures.
•F4/80+ concentrated in the perivascular
spaces in the sub-odontoblastic zone and
inner pulp.

15. 1. PULPAL REACTION TO CARIES
3) - INFLAMMATORY AND IMMUNE REACTIONS:
Odontoblasts play a role in the humoral immune
response to caries.
Immunoglobulin IgG, IgM, and IgA have been
localized in the cytoplasm and cell processes of
odontoblasts in human carious dentin, suggesting
that these cells actively transport antibodies to
the infection front.

16. 1. PULPAL REACTION TO CARIES
3) - INFLAMMATORY AND IMMUNE
REACTIONS:
N.B: In the most advanced phase of carious
destruction, the immune response is
accompanied by immuno-pathologic
destruction of pulpal tissue.

17. 2 - PULPAL REACTION TO LOCAL
ANESTHESIA
VASOCONSTRICTORS:
• Such as: lidocaine and
1:100,000 or 1:80,000
epinephrine.
• Benefits: enhance the duration
of anesthesia.
• Side effect: reduce the blood
flow of the pulp.
N.B: The supplemental anesthetic
techniques cause more severe
reduction or even transient
cessation of pulpal blood flow.

18. 2 - PULPAL REACTION TO LOCAL
ANESTHESIA
N.B:The effect of intrapulpal anesthesia on the
pulp is not considered, since it is used
during root canal therapy when other
anesthetic administrations are insufficient.
• However, during pulpotomy in tooth with
immature apex, no difference was
detected on follow-up of over 24 weeks
after administration of intrapulpal
anesthesia that contain epinephrine.

19. 3 - PULPAL REACTION TO RESTORATIVE
PROCEDURE
One key requirement of a successful restorative
procedure maintaining the pulp vitality is to cause
minimal additional irritation of the pulp so as not to
interfere with normal pulpal healing.
Pulp reaction to restorative procedure is controlled by:
1.Degree of Pretreatment Pulp Inflammation.
2.Degree of Physical Irritation
3.Biologic and Chemical Irritation
4.Proximity of Restorative Procedures to Pulp

20. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
1) Degree of Pretreatment Pulp Inflammation:
In the absence of severe spontaneous symptoms or
pulp exposure, the clinician cannot accurately
determine the degree of preoperative pulpal
inflammation. Thus, every effort should be made to
minimize added irritation during restorative
procedures.
In cases of aseptic mechanical exposures, exposure
longer than 24 hours associated with the formation of
a bacterial biofilm that is difficult for the pulpal
immune responses to eliminate.

21. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
2) Degree of Procedure Physical
Irritation:
• Heat:
Any restorative procedures leads to
increase in pulpal temperatures
 In case of 10° C rise →
irreversible pulp pathosis
 In case of 20 C rise → pulp
abscess formation
Gradual controlled heat
application over a large area may
not cause adverse reactions in
the pulp.
If the cavity floor ≤ 0.5 mm from
the pulp, areas of coagulation
necrosis could be detected.

22. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
2) Degree of Procedure
Physical Irritation
• Desiccation:
• It is the aspiration of
odontoblastic nuclei into
dentinal tubules.
• It is transient, within 7 to 30
days there is autolysis of the
aspirated cells and formation
of reactionary dentin.
• The pulp in cases with
aspirated odontoblasts,
following desiccation for 1
minute, was not sensitive to
clinical scraping with an
explorer.

23. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
3) Biologic and Chemical Irritation:
The sources of microbial irritaion:
 cariogenic microorganisms remaining on cavity floor.
 contamination with salivary microorganisms.
 contamination with bacteria from water lines.
 Prompting the use of cavity disinfection (chemicals
irritation), and so the most common irritant is etching
agents.

24. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
N.B:
Once dentin is exposed, there is constant
outward flow of dentinal fluid that minimizes
the inward flow of any noxious agents. this
may aid in the reduction of irritation from
residual microbial factors in dentinal tubules.

25. III. PULPAL REACTIONS TO RESTORATIVE
PROCEDURES
4) Proximity of Restorative Procedures to Dental
Pulp & Surface Area of Dentin Exposed = Depth
and/or Width of a Tooth Preparation
There is an reaction, with a greater likelihood of
the pulp undergoing irreversible pathosis, as the
carious lesion progresses towards the pulp,
particularly when the remaining dentin thickness
(RDT) is less than 0.5 mm.

26. III. Pulpal reaction to restorative
procedure
4) Proximity of Restorative Procedures to Dental Pulp &
Surface Area of Dentin Exposed: = Depth and/or
Width of a Tooth Preparation:
N.B:
With the passage of time following cavity preparation,
there is reduction in the permeability of RDT, due to
rapid deposition of reactionary dentin, the migration of
large proteins into the tubules, and/or the diminution
of tubule diameter as dentin becomes more sclerotic.

27. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
5) Permeability of remaining dentin & related
odontoblastic :
The dentin is not uniformly permeable, and that
permeability depends on factors such as;
a) The location within the same tooth the
pulp.
b) The age of the patient.
c) The presence of pathologic conditions.

28. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
5) Permeability of remaining dentin and related
odontoblastic :
a) The location within the same tooth:
The tubular diameter increases from about 0.6
to 0.8 μm close to the DEJ to about 3 μm at the
pulp. Given that bacterial cells are about 0.5 to 1
μm in diameter, it is evident that in deep cavity
preparations, particularly when total-etch
procedures are employed, bacteria can migrate
through the remaining dentin into the pulp.

29. III. PULPAL REACTION TO RESTORATIVE
PROCEDURE
5) Permeability of remaining dentin and
related odontoblastic :
b) The age of the patient,:
The width of peritubular dentin increases with
age, causing reduction in tubular lumen or
sclerosis.

30. III. PULPAL REACTION TO RESTORATIVE
PROCEDURES
5) Permeability of Remaining Dentin and Related
Odontoblastic :
c) The presence of pathologic conditions such as dental
caries.
• In superficial dentin, formation of caries crystals within
the tubules of inner undemineralized dentin →
decrease in permeability in dentin.
• Related odontoblasts, it was shown that irritation from
cavity preparation increased the odontoblastic
permeability only at the site of the cavity preparation

31. III. PULPAL REACTION TO RESTORATIVE
PROCEDURES
5) Permeability of Remaining Dentin and Related
Odontoblastic :
N.B:
In addition to the physical barrier to permeability
and the production of reactionary or reparative
dentin, the odontoblastic layer may in fact
contribute to the host response of the dental
pulp by expressing important inflammatory
mediators or recognize bacteria through toll-like
receptor

32. III. PULPAL REACTION TO RESTORATIVE
PROCEDURES
6) Patient Age:
• Resting pulpal blood flow (PBF),
• Response to cold application, decrease with
age.
• Reduction in pulpal neuropeptides.

33. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
1) - Direct Effects 2) - Indirect Effects
1) Direct effects of restorative materials:
• Certain cytotoxic components of resin monomers
(Triethylene glycol dimethacrylate & 2-hydroxyethyl
methacrylate).
• Some of the components of resin restorations are
released at cytotoxic levels after polymerization is
completed.

34. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
These chemicals have either:
 A short lived and in the absence of bacteria,is
reversible
Or
 Irreversible prolonged cytotoxicity,stimulation of
hypersensitivity reactions, or impairment of the host
immune response to bacteria.
N.B:
•Subtoxic concentrations of certain agents are capable of
eliciting allergic reactions in humans.

35. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
2) Indirect effect of restorative materials:
The technique sensitivity of certain materials
predisposes them to faulty bonds to tooth
structure that can translate to dentin
hypersensitivity, recurrent disease, and pulpal
inflammation or necrosis.

36. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
During the etching process:
The more highly mineralized peritubular dentin is
preferentially dissolved, leaving free collagen fibrils and
opening lateral tubular branches. Applied resin infiltrates
the exposed collagen mesh, creating a layer5 to 10 μm
thick referred to as the hybrid layer.
• If the preparation is too dry, the collagen fibrils collapse.
N.B:
The optimal degree of hydration of the preparation surface
can vary from material to material.

37. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
N.B:
• It is recommend to rehydrate the fragment
segment of the tooth prior to bonding, to
increase the mechanical and the microbial
seal.
• This is particularly important with a
complicated crown fracture where the pulpal
protection by intact dentin is absent.

38. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
Pulpal irritation is not considered a negative sequela all
the time, the irritant potential ofcertain restorative
materials has a usefulmotivated effect on odontoblasts
in case of direct & indirect pulp capping.
The outcome of such treatments depends on:
•The biocompatibility of used medicaments.
•The ability to seal the cavity.
•A combination of the above.
•Ability to control hemorrhage at the exposure site.

39. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
• For example:
• Calcium Hydroxide
• Zinc Oxide Eugenol
• Mineral Trioxide Aggregate
• Hemostatic Agents
• 2% chlorhexidine or 5.25% sodium
hypochlorite

40. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
CALCIUM HYDROXIDE
In direct pulp capping:
It induces the formation of dentinal bridge
•Aqueous suspensions preparation: causes
superficial necrosis of pulpal tissue followed by
tissue displaying low-grade inflammation .Within 30
days, the tissue subjacent to the necrotic zone has
reorganized and resumed normal architecture.
•Hard-setting preparation: is effective in eliciting
dentinal bridge formation with a much smaller to
nonexistent necrotic zone.

41. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
CALCIUM HYDROXIDE:
In indirect pulp capping:
•The Application of calcium hydroxide to
intact dentin appears to induce sclerosis by
promoting crystal precipitation within the
tubules, accompanied by reductions in
permeability.
•The irritation potential is dependent on the
remaining dentin thickness and permeability.

42. IV. PULPAL REACTION TO
RESTORATIVE MATERIALS
MATERIALS CONTAINING ZINC
OXIDE AND EUGENOL:
ZOE is used for;
• Anesthetic properties:
It has been shown to block
transmission of action
potentials in nerve fibers &
suppress nerve excitability in
the pulp when applied to deep
excavations.
• Antiseptic properties:
It inhibits bacterial growth on
cavity walls.
• Sealing ability:
It has good adaptation to
dentin.

43. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
DIRECT PULP CAPING WITH
MTA
Mineral Trioxide Aggregate
(MTA):
Indication:
• In pulps with traumatic or
carious exposure, for
allowing the formation of a
reparative dentin bridge
and maintain continued
pulp vitality.

44. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
DIRECT PULP CAPING WITH MINERAL TRIOXIDE
Mineral Trioxide Aggregate (MTA):
•At 1st week, no sign of necrosis close to the
exposure site, and odontoblast-like cells are
observed at the periphery with the deposition
of calcified bridge.
•At 2nd weeks, complete calcified bridge
formation just below the exposure site.

45. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
• DIRECT PULP CAPING WITH MINERAL TRIOXIDE

46. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
Direct Pulp Caping with Mineral Trioxide Aggregate (MTA):
Success was determined:
•Radiographically.
•Disappearance of subjective symptoms.
•Normal pulp testing with cold.
•continued root formation on immature teeth.
Success depends on the prevention of bacterial ingress by
the placement of a well-sealed restoration must also be
provided.

47. IV. PULPAL REACTION TO RESTORATIVE
MATERIALS
Use of HEMOSTATIC AGENTS
and DISINFECTANTS on
Direct Pulp Exposures:
The mechanical exposure
of a healthy pulp created
during cavity preparation
could be disinfected with
either 2% chlorhexidine
or5.25% sodium
hypochlorite.

48. PULPAL REACTION TO LASER
PROCEDURE
• Laser use on soft / hard
tissues has potential
benefits of efficiency,
reduced sensitivity,
disinfection, and precision.
• There are several different
types of laser available that
depend on the wavelength,
active medium, emission
mode, delivery system,
power output, and duration
of application.

49. PULPAL REACTION TO LASER
PROCEDURE
• The main types available in dentistry today are:
• The CO2 laser (10,600 nm).
• Er:YAG laser (2940 nm), has a high affinity for
water and hydroxy-apatite.
• Ho:YAG laser (2120 nm), has high affinity to water but
not to tooth structure.
• Nd:YAG laser (1064 nm), has high affinity for
waterand pigmented tissues and offers good
hemostasis.
• HeNe laser (632 nm). laser Doppler
• GaAlAs laser (720-904 nm).laser flowmetry and in
treating dentin hypersensitivity.

50. PULPAL REACTION TO VITAL BLEACHING
TECHNIQUE
Using of strong oxidizing agents(such as carbamide
peroxide & hydrogen peroxide) may cause:
• Minor inflammation up to 2 weeks → reversible
pulpitis, prevented by treating the teeth with flourides
and by correcting defective restoration.
• Sever inflammation → irreversible pulpitis → pulpal
necrosis.

51. PULPAL REACTION TO VITAL
BLEACHING TECH
Clinical symptoms are likely to be due to increases in
neuropeptides in the pulp.
N.B: A recent studies showed that 10% carbamide
peroxide in a custom tray for 6 weeks was
safe for the pulp health, while light-& laser-
activated bleaching systems, due to increase
neuropeptides expression in the pulp to
significant levels.

52. PULPAL REACTION TO PERIODONTIAL
PROCEDURES
It is much more common for pulp necrosis or
failed healing of periradicular lesions to
present clinically with signs of periodontal
disease than for periodontal disease to cause
pulpal pathosis.

53. PULPAL REACTION TO PERIODONTIAL
PROCEDURES
1°ry pulpal - 2°ry periodontal
pathosis:
is particularly evident with
pulp chamber / coronal
third perforation, vertical
root fractures or congenital
tooth defects.
1°ry periodontal - 2°ry pulpal
pathosis:
is rare to occur but
periodontal scaling and root
planning results in dentin
hypersensitivity.

54. PULPAL REACTION TO PERIODONTIAL
PROCEDURES

55. PULPAL REACTION TO PERIODONTIAL
PROCEDURES

56. PULPAL REACTION TO PERIODONTIAL
PROCEDURES
(WHY?)
It is more likely for microbial irritants to move
outward from a vital / necrotic pulp to cause
periodontal breakdown than for them to
move inward from a periodontal pocket to a
vital pulp causing irreversible pathosis.

57. PULPAL REACTION TO PERIODONTIAL
PROCEDURES
(HOW?)
The outward dentinal fluid flow in teeth with
vital pulp contributes to the resistance to
ingress of bacteria in sufficient amounts to
cause a clinically significant disease process.
Once the pulp degenerates, dentinal fluid flow
no longer exists.

58. PULPAL REACTION TO ORTHOGNATHIC
SURGERY
Osteotomy of the jaw → Disruption in the
blood supply
• Postoperative manifestations common with
traumatic injuries.
• Inflammation and/or necrosis.

59. PULPAL REACTION TO ORTHOGNATHIC
SURGERY
N.B:
Studies have shown that if a safe distance of
5 to 10 mm is maintained between the site of
the surgery and the teeth, minimal disruption
occurs. In most cases, the blood flow is
regained within months of the surgery.

60. PULPAL REACTION TO ORTHOGNATHIC
SURGERY
N.B: Studies have shown that if a safe distance
of 5 to 10 mm is maintained between the
site of the surgery and the teeth, minimal
disruption occurs.
N.B: In most cases, the blood flow is regained
within months of the surgery.

61. PULPAL REACTION TO IMPLANT
PLACEMENT AND FUNCTION
The placement of implants requires multifaceted
preoperative radiographic techniques.
(WHY?)
The lack of attention to:
• 3-dimensional anatomy of the site of implant
placement.
• the orientation of neighboring teeth.
 perforating the root and devitalizing the pulp.

62. PULPAL REACTION TO IMPLANT
PLACEMENT AND FUNCTION
It is usually recommended to place theimplants at a site
free of periradicular lesion.
(WHY?)
Microbial irritants may interfere with osseointegration.
• Some studies claimed that teeth with periradicular
lesions may reduce the success of neighboring
implants, even if adequate endodontic treatment is
performed.

63. PULPAL REACTION TO IMPLANT PLACEMENT
AND FUNCTION
However, recent data suggest that immediate
implant placement in sites that have been
adequately débrided is successful.
Furthermore, implants that are not mobile
buthave apical periimplant lesions have
beensuccessfully treated with local
débridementand “implant-apex resection”
procedures.

64. REGENERATIVE POTENTIAL OF DENTAL
PULP
Recent studies and case reports suggest that the
dental pulp has great regenerative potential,
particularly in the immature permanent tooth.
(HOW?)
Stem cells from the apical papilla (SCAP) of
immature teeth have likewise been identified and
have been shown to develop into dentinogenic
cells, given the proper stimulation.

65. REGENERATIVE POTENTIAL OF DENTAL
PULP