Descriptive presentation on Calcium Hydroxide.

1. Calcium Hydroxide
1
GUIDED BY -Dr Suvarna patil
-Dr.Ashish Medha
-Dr.Sharanu srivastav
-Dr.Girish umashetty
-Dr.Snehal savagave
-Dr.Rutuja chopade
-Dr.Priyatam karade
-Dr.Anil bhaghat
-Dr.Ravindra jadhav Presented by – Shivani M. Raghuwanshi

2. Contents
1) Introduction
2) History
3) Manufacture
4) Classification
5) Composition
6) Mode of supply
7) Applications
8) Zones
9) Properties
10) Vehicles of calcium hydroxide
11) Clinical applications
12) Resorption induced in deciduous teeth
13) Removal of calcium hydroxide
14) Advantages & disadvantages of calcium hydroxide
2

3. 3
Introduction
• Calcium hydroxide is a white odourless
powder with a molecular weight of 74.08
g/mol.
• Chemical structure : Ca(OH)2
• It has a strong base with a high pH
12.5-12.8 .

4. History
Nygren (1838)
“fistula dentalis”
Codman (1851)
1st attempt to
preserve dental
pulp
Hermann (1920)
Intro it as a pulp
capping agent to
promote healing
4

5. 5
• Introduction of this material
in the United States
Teuscher &
Zander 1938
• first reports dealing with
successful pulpal healing
appeared in the literature
Between 1934
and 1941.
• use of Ca(OH)2 for apical
closure
In 1959
Granath.
Since then, and mainly after the Second World War, the clinical indications
for its use were expanded.

6. Manufacture
6

7. Mode of action
• Its biological properties are achieved by its dissociation into Ca2+
& OH- ions
• Ca2+ 54.11%
• OH- 45.89%
7
Ca2+
• Activates calcium dependant
ATP reaction
Hard tissue formation
OH –
• Provides alkaline pH which
Neutralizes lactic acid.
• Activates alkaline phosphatase
Hard tissue formation

8. 8
Setting time.
Fast setting
(chemical
cure)
Controlled
setting (light
cure)
Slow setting Non setting
Ex : Dycal
- liner or
subbase.
Ex : Calcimol LC ,
VLC Dycal
-direct or
indirect pulp
capping.
Ex: (Sealapex
/Apexit) ,
Metapex
temporary
sealing material
which sets slow
in presence of
saliva.
supplied as
powder mixed
with various
vehicles .
- intracanal
medicament.
Classification

9. • Based on the form of availability:
1. Powder to be mixed with different vehicles
2. Single paste ex: RC Cal , Endocal , VLC Dycal
3. Two –paste system ex: Dycal
• Based on vehicle used:
1. Aqueous vehicle
2. Oily vehicle
3. Viscous vehicle
9

10. Composition
• Base paste
1. Glycol salicylate 44% Reacts with Ca(OH)2 & ZnO
2. Titanium dioxide 12-14% Fillers
3. Barium sulphate 32-35% Radiopacifier
4. Calcium tungstate
or sulphate 14-15%
• Catalyst paste
1. Calcium hydroxide 50-60% Reactive ing.
2. Zinc oxide 10%
3. Zinc Stearate 0.5 % Accelerator
4. Ethylene toluene
sulfonamide 39.5% carrier
10

11. • Light cured calcium hydroxide
1. Urethane dimethacrylate resin (BISGMA)
2. HEMA
3. Polymerizing activator
4. Calcium hydroxide
5. Barium sulphate
6. Camphoroquinone
Advantages: strength, no solubility in acids, minimal solubility in
water, control on W.T.
11

12. Mode of supply
1. Can be supplied in powder form
mixed with saline or water to form
a thick paste .
2. Two paste system (one base paste
another catalyst paste)
3. Single paste system (visible light)
12

13. 13
Pulp capping
Pulpotomy
Apexification
Management of
traumatized teeth
Management of
resorption
Endodontic
sealer
Pediatric
obturation
material
Intracanal
medicament
Applications

14. Properties
Mechanical Properties:
• Elastic modulus- 0.37 GPa/m2 (Low – Hence, limits the use in
areas that are not critical to support of restoration)
• Compressive strength >24 hr-10-24 MPa
• Tensile strength- 1 MPa
• Setting time: 2.5- 5.5 mins.
• Calcium ions concentration is 54.11% & Hydroxyl ions
concentration is 45.89% .
14

15. Chemical properties:
• It is low solubility in water (ranges between 0.4% & 7.8%) with
increases with temp.
• A certain extent of solubility is necessary for Ca(OH)2 to produce
its therapeutic effects.
• Insoluble in alcohol
Thermal insulation:
• When Ca(OH)2 is used in sufficient thickness , can provide
thermal insulation
Biological properties:
• It is achieved by its dissociation into Ca2+ & OH- ions resulting in
hard tissue deposition & antibacterial effect.
15

16. 1.) Anti-Inflammatory effect
• The elevated pH inhibits the substrate adherence capacity of
macrophages and decreases or eliminates the MMP 8.
• Improving tissue circulation and controlling exudation.
• Calcium Hydroxide acts as local buffer against acidic
inflammatory reactions -
16
Activate alkaline phosphatase
Alkaline pH neutralize lactic acid to prevent
further destruction of mineralized tissue.

17. 2.) Calcific barrier formation.
• Ca(OH)2 produces an organic matrix which will mineralize
within 4-6 weeks.
• It stimulates :
- dentin matrix sequestration
- ATP activation
- Diffusion of growth factors (TGF)
- Activates alkaline phosphatases by its high pH.
• This induces signaling of odontoblast like differentiation followed
by reperative dentin secretion.
17

18. 3.) Antimicrobial effects
• The antimicrobial activity of Ca(OH)2 is related to the release of
OH- in an aqueous environment (Siqueira 2001).
• Hydroxyl ions are highly oxidant free radicals that show extreme
reactivity with several biomolecules.
• The lethal effects of hydroxyl ions on bacterial cells are probably
due to the following mechanisms (Siqueira & Lopes 1999):
18
International Endodontic Journal, 44, 697–
730, 2011

19. 19
• Hydroxyl ions causes destruction of
Phospholipids by lipid peroxidation leading
to cell membrane damage
Destruction of the
bacterial cytoplasmic
membrane. (Cotran
et al. 1999)-
• Alkaline pH leads to breakdown of ionic
bonds of proteins and disturbs biological
activity of enzymes and cellular metabolism
Protein lysis. (Voet
1995)
• Hydroxyl ion damages the bactericidal DNA
by splitting the strands and inhibiting DNA
replication
Bacterial DNA
damage. (Imlay and
Linn 1988)-
Mechanism:

20. 20

21. Factors limiting antibacterial action of
Ca(OH)2
• Buffering capacity of dentin
• Resistant strains – E .faecalis & candida albicans seems to be
resistant to Ca(OH)2 since they can withstand high pH .
• E.faecalis is capable of migrating upto 250 um in dentinal tubules.
21

22. 4.) Tissue-dissolving property :
• Interim dressing with Ca(OH)2 for 1 week or more may ensure
dissolution of pulpal fragments due to its long term solvent effect.
• The combined use of sodium hypochlorite & Ca(OH)2 has a good
potential for removing autolyzed pulpal tissue.
22

23. 5.) Mineralization activity
• The alkaline pH induced not only neutralizes lactic acid but also
activate alkaline phosphatases that play an important role in
hard-tissue formation (Estrela et al. 1995).
• The pH necessary for the activation of this enzyme varies from
8.6 to 10.3
• Alkaline phosphatase is a hydrolytic enzyme that acts by means
of the liberation of inorganic phosphatase from the esters of
phosphate.
23
International Endodontic Journal, 44, 697–
730, 2011

24. 24

25. • The formation of mineralized tissue after contact of calcium
hydroxide with conjunctive tissue has been observed from about
the 7th to the 10th day.
• Dentine is observed about 15 days after treatment.
25

26. 6.)Anti-Endotoxin activity
• Endotoxin, a part of the cell wall of all Gram-negative bacteria is
composed of polysaccharides, lipids & proteins and is referred to
as lipopolysaccharide (LPS)
• They stimulate competent cells to release chemical mediators
such as tumour necrosis factor (TNF), interleukin1 (IL-1), IL-5,
IL-8, alpha-interferon and prostaglandins.
26

27. • In a laboratory study, Safavi & Nichols (1993) evaluated the effect
of Ca(OH)2 on bacterial LPS and concluded that it hydrolysed the
highly toxic lipid A molecule that is responsible for the damaging
effects of endotoxin.
• In another study, they found that Ca(OH)2 transformed lipid A
into fatty acids and amino sugars, which are atoxic components
(Safavi & Nichols 1994).
• Ca(OH)2 inactivates endotoxin, in vitro and in vivo, and appears
currently the only clinically effective medicament for inactivation
of endotoxin.
27
International Endodontic Journal, 44, 697–
730, 2011

28. 7.)Antifungal activity
• Fungi have occasionally been found in primary root canal
infections.
• The alkalinity of saturated Ca(OH)2 solution may not have any
effect on C. albicans.
28
C. albicans survives in a
wide range of pH values.
Provides the Ca2+ ions
necessary for the
growth and
morphogenesis of
Candida.
• Siqueira et al. (2001) reported that that the combinations of
Ca(OH)2 with camphorated paramonochlorophenol or CHX
have the potential to be used as effective..

29. Cytotoxicity And Biocompatibility Of
Calcium Hydroxide
1. Effect on Pulp vitality
2. Effect on Periapical tissue
3. Effect on Dentin
29

30. 1. Effect on Pulp Vitality
• Pulp tissue is affected by environmental impacts such as heat,
mechanical trauma as well as microbial toxins.
• After multiple injuries, the pulp cells have the capacity to repair
and differentiate into odontoblasts and produce dentin matrix
proteins during wound healing process.
• Therefore, not all the inflammatory reaction leads to permanent
damage
30

31. • Calcium Hydroxide when used acts as a protective barrier for
Pulpal tissues by blocking the Dentinal Tubules and
Neutralisation of attack of inorganic acids and leached products
from certain cements and filling materials
• Healing with Calcium hydroxide forms 3 zones-
Grossman 13th edition 31

32. Healing with high pH(11-13) calcium
hydroxide.
1. Zone of obliteration:
- This zone can be visualized after 1 hr of contact between
Ca(OH)2 & the tissue which is induced by the pressure of
application & chemical injury due to high conc. of OH- ions.
- The pulp tissue which is immediately in contact with
Ca(OH)2 is completely deranged & distorted because of
high alkalinity.
- It consists of debris, dentinal fragments, blood clot, blood
pigments.
32

33. 2. Zone of coagulation necrosis [Schroder’s layer /Stanley’s
mummified zone] :
- It is 0.3-0.7 mm thick.
- It consists of devitalized tissue without complete
obliteration of its structural architecture.
- It causes slight but sufficient stimulation to the subjacent
normal pulp tissue.
33

34. • Line of demarcation:
- It exists between zone of coagulation necrosis & subjacent
normal pulp tissue.
- It is due to reaction of Ca(OH)2 with tissue protein to form
proteinate globules.
34

35. 3. Zone of dentin bridge formation:
- Increase in formation and organisation of collagen fibres.
- Modified cell rich zone formed by proliferation of
mesenchymal cells and fibroblasts.
• Undifferentiated mesenchymal cells differentiate into
Preodontoblasts and columnar odontoblasts.
• Korff’s fibres(Argyrophilic fibres) arrange perpendicular to the
line of demarcation.
• Sporadic tubular formation within collagenous matrix.
• After 7 days, cellular inclusions and superficial capillaries
become engulfed & are partial or total obliterated as matrix
thickens and becomes more differentiated.
35

36. Healing with low pH (9-10) calcium
hydroxide.
• This formulation produce a high quality , more uniform
dentin bridge without the induction of a visible
intermediate coagulated necrotic layer.
• There is less tissue damage due to lower pH values .
36

37. 2. Effect on Periapical tissue
• Some researchers support accidentally extrusion Or
intentional pressing of calcium hydroxide beyond the root
canal and into the periradicular tissue. They claimed that
calcium hydroxide enhances the healing and osseous repair
by direct effect on inflamed tissues
• Extrusion of calcium hydroxide paste containing barium
sulfate beyond root canal can obscure the apex & is not
easily resorbed over time and it also enhances the release of
inflammatory mediators responding to (PMMA) particles.
37

38. 3. Effect on Dentin
• Diffusion of hydroxyl ions through dentine
• For calcium hydroxide to act effectively as an intracanal
medicament, hydroxyl ions must be able to diffuse through
dentine.
• Diffusion of hydroxyl ions through dentine depends on
38
The period of
medication,
Diameter of
dentinal
tubules
(cervical
versus apical)
Smear layer
removal
(patency of
dentinal
tubules)
Molecular
weight
(Nerwich et al.
1993).

39. Buffering effect of dentin on Ca(OH)2
• To be effective against bacteria located inside the dentinal
tubules, the hydroxyl ions from calcium hydroxide should diffuse
into dentine at sufficient concentrations.
• It has been reported that dentine has buffering ability because of
the presence of proton donors such as H2PO4 , H2CO3 and HCO3
in the hydrated layer of hydroxyapatite, which keep the pH
unchanged.
• Therefore, in order to have antibacterial effects within dentinal
tubules, the ionic diffusion of calcium hydroxide should exceed
the dentine buffer ability, reaching pH levels sufficient to destroy
bacteria.
39
International Endodontic Journal, 32,
361±369, 1999

40. • According to Fava (1991), the Ideal Vehicle should :
• Allow a gradual and slow Ca². and OH- ion release
• Allow slow diffusion in the tissues with low solubility in tissue
fluids.
• Have no adverse effect on the induction of hard tissue deposition
• 3 types of vehicles are used
1. Aqueous vehicle
2. Viscous vehicle
3. Oily vehicle 40
Vehicles

41. Aqueous vehicle
• Water
• Anesthetic solutions
• Chlorhexidine
• Ringer lactate solution
• Methylcellulose
• Carboxymethylcellulose
41

42. Clinical importance:
• Ca2+ & OH- are rapidly released
• Direct contact with tissue & the tissue fluids causing it to be
rapidly solubilized & resorbed by macrophages.
• Increasing the no. of appointments.
Uses :
1. Direct/Indirect pulp capping
2. Pulpotomy
3. Apexification
42

43. Viscous vehicle
• Glycerine
• Polyethylene glycol
• Propylene glycol
Clinical importance:
• Reduce Ca2+ & OH- ions more slowly for extended periods.
• Lower solubility due to its high mol.wt.
• Pastes remains in direct contact with vital tissues for extended
time intervals
• Appointments & redressings of root canal is reduced
43

44. • Uses:
1. Apexification
2. T/T of large periapical lesions
3. Acute apical periodontitis
4. Interappt. dressings in cases of vital pulpotomy
5. Endodontic retreatment after surgical failures
44

45. Oily vehicles
• Olive oil
• Silicone oil
• Camphorated parachlorophenol
• Oleic, linoleic & isostearic acid
Clinical importance:
• Lower solubility & diffusion of pastes within the tissues.
• Pastes containing this kind of vehicle may remain within the root
canals for longer periods .
Uses :
• Perforation defects after internal resorption.
• Reversal of external resorption.
45

46. 46
Clinical
Applications

47. Role in conservative dentistry
1. Cavity bases & liners:
Used to protect against thermal shock , chemical irritation.
• Advantages in using it as cavity liner-
47
They have a rapid initial
set in the cavity under the
accelerating effect of
moisture in the ambient
air of the oral cavity and
from within the dentinal
tubules
They do not interfere with
the setting reaction of Bis-
GMA resins & are
therefore the lining
material of choice under
composite resin material,
It is generally considered
that the initial set of the
material in thin sections is
sufficiently hard to resist
the applied condensation
pressures that are
required even for lathe cut
amalgam alloys.

48. • Disadvantages as cavity liner -
• The disappearance of the early versions of these materials from
beneath restorations was probably due to the effects of bacteria
and microleakage.
48

49. 2.) Indirect pulp capping:
• Indirect Pulp Capping is a technique for avoiding pulpal exposure
in treatment of teeth with deep carious lesions with no clinical
evidence of pulpal degeneration or periapical disease
• Purpose- Arrest the carious process by promoting dentinal
sclerosis , remineralization of carious dentin and preserving
pulpal vitality.
• Ca(OH)2 is being used as an antibacterial agent and mild pulp
stimulant to produce irritation dentine.
49

50. 3.) Direct pulp capping:
• Direct Pulp capping is the procedure in which a medicament is
applied to exposed to pulp in an attempt to preserve its vitality.
• Forms available-
1. Pure calcium Hydroxide- pure Ca(OH)2 necroses
approximately 1.5 mm of the pulp tissue.
- It causes mild irritation to adjacent vital pulp which will initiate
inflammatory response and in absence of bacteria heal with
hard tissue barrier.
2. Light cured Calcium Hydroxide - in contrast to regular Dycal at
the exposure site, Prisma VLC Dycal caused no inflammation.
50

51. 51
• Ca(OH)2 induces beneficial effects due to chemical injury caused by the
hydroxyl ions.
• A limited necrosis is induced against the vital pulp tissue & provokes a slight
irritation and stimulates pulp repair.
• Vascular and inflammatory cell migration and proliferation control
mesenchymal and endothelial pulp cells & also the formation of collagen .
• Odontoblasts differentiate & contribute to the formation and mineralization of a
reparative dentinal bridge. Dentinal bridge develops following direct pulp
capping.
It is known that a variety of proteins are incorporated into the dentin matrix during
dentinogenesis.
Of particular importance to the topic of pulp capping is that at least two of these
proteins, (BMP) & (TBF-β1), have demonstrated the ability to stimulate pulp repair.
Hindawi Publishing Corporation Mediators of Inflammation Volume 2015,

52. Histological picture after DPC-
• small necrotic zone of amorphous
structure is secreted bordered on pulp
side by small hemophilic layer of calcium
proteinate
Immediately-
• Inside basophilic zone at junction of pulp
small areas of calcification results in
osseous reparative tissue.
• Fibroblasts seen
After 2 weeks-
• Necrotic zone disappears leaving empty
space- basophilic zone has dystrophic
calcification on pulpal border.
• Fibroblasts to odontoblasts
After 4 weeks-
• 0.1mm dentin & whole basophilic zone is
mineralized
After 8 weeks- 52

53. 53

54. 54
Role in
Endodontics
Pulpotomy
Apexification
Apexogenesis
Root resorption
management
Weeping canals
Perforations
Intracanal
medicament
Endodontic sealer
Calcium hydroxide
points

55. 1.) Pulpotomy
• Pulpotomy is surgical removal of entire coronal pulp presumed to
be inflamed or infected, leaving intact vital radicular pulp in
canals
• Indications-
• Permanent teeth with mechanical, carious or traumatic exposure
in young permanent teeth with open apex
• Slightly inflamed pulp open apices
• Calcium hydroxide is used because-
1. Predictability in dentin bridge formation
2. Healing of radicular pulp tissue 55

56. 2.) Apexification
• Creation of a proper environment for formation of the calcified
barrier involves cleaning and shaping of the canal to remove
debris and bacteria, followed by placement of a suitable material
to the apex (Pitt Ford 2002).
56

57. • Ca(OH)2 is used as a temporary canal filling material and has a
bactericidal effect.
• This calcified barrier consists of osteocementum or other bone-
like tissue (Grossman 1988).
• The residual undamaged pulp tissue and the odontoblastic layer
associated with the pulp tissue resume their matrix formation
and subsequent calcification is guided by the reactivated (HERS).
• The usual time required to achieve apexification is 6–24
months (average 1 year ± 7 months).
57

58. 3.) Apexogenesis
• Apexogenesis is defined as a vital pulp therapy procedure
performed to encourage continued physiologic development and
formation of the root end . -Cohen.
• Mechanism of action of calcium hydroxide
• Calcium hydroxide stimulated the epithelial cells of Hertwig's
sheath and the undifferentiated progenitor cells and thus aided in
continued apical root formation. Its antibacterial property and
inherent alkalinity are also beneficial.
• Demerits: Long-term usage of Calcium hydroxide may weaken
the root
58

59. 4.)Root Resorption
• Root resorption is the resorption that affects the cementum
and/or dentine of the root .
• The alkaline pH of Ca(OH)2, which permeates through the
dentine, reduces the osteoclastic activity and stimulates repair.
• The initial treatment of choice for internal root resorption is to
pack the canal & the resorption lacuna with Ca(OH)2 paste.
• The Ca(OH)2 will tend to necrotize remaining tissue in the lacuna,
and the necrotic remnants are then removed by irrigation with
sodium hypochlorite.
59

60. • Ca(OH)2 should be placed into the resorptive defect at 3-month
intervals until there is evidence of hard-tissue repair, confirmed
by both radiographic and direct examination through the access
cavity.
• When the physical barrier has been established, the defect can be
filled with Gutta-percha or MTA.
60

61. 5.) Weeping canals
• It’s a condition to treat the tooth with constant clear or reddish
exudate associated with a large apical radiolucency.
• Such a tooth is often asymptomatic, but it may be tender to
percussion or sensitive to digital pressure over the apex. If
cultured, the drainage will not generally support bacterial
growth.
• When the pulp chamber is opened at the start of the
appointment, a reddish discharge may appear, whereas at the
succeeding appointment the exudate will be clear.
61

62. • If such a tooth is left opened under a rubber dam for 15–30 min,
the exudate will stop; however, a similar condition will still be
present at the next appointment even though canal preparation
to an acceptable size has been achieved.
• This is referred to as a ‘weeping canal’ (Weine 2004).
• The best way to stop the exudate in such cases is to dry the canal
with sterile paper points and to place Ca(OH)2 paste in the canal.
62

63. 63
The calcifying
potential of Ca(OH)2
may start to build up
bone in the lesion
The caustic action of
Ca(OH)2 cauterises
residual chronically
inflamed tissue (Weine
2004)
Basic pH, which
converts the acidic pH
of periapical tissues to
a more basic
environment.
Calcium Hydroxide is said
to contract capillaries and
for fibrous mechanical
barrier
Mechanism

64. 6.) Perforation repair
• Root perforation is the artificial communication between root
canal system to supporting tissues of teeth and oral cavity.
• Root or furcation perforations can cause failure of root canal
treatment, leading to tooth loss .
• Perforations below alveolar crest and non communicating can be
treated with a mix of calcium hydroxide , CMCP Barium Sulfate.
• After months – bridge is formed and then it is removed and final
obturation using Gutta Percha .
64

65. 65
Easy
manipulatio
n
Rapid
resorption
when
extruded
into the
periodontiu
m
Promotion
of the
reorganizati
on of
periodontal
tissues
Induction of
mineralized
material
Ca(OH)2 benefits in this treatment

66. 7.)Intracanal
medicament
• According to Weine , (2004) an intracanal medicament is an
antimicrobial agent that is placed inside the root canal between
treatment appointments, in an attempt to destroy remaining
micro-organisms and prevent reinfection.
• The application of calcium hydroxide paste at intervals of at least
7 days is able to eliminate and/or reduce the total number of
bacteria surviving even after biomechanical preparation.
• Different techniques can be used for the placement of calcium
hydroxide in the canals.
66

67. 67
Tan et. Al stated the use of
Syringe and
#25 finger
spreader
Syringe and
#4 rotary
lentulo spiral
Specially
designed
paste carrier .
Tan, J.M.E., Parolia, A. and Pau, A.K.P. Intracanal Placement of Calcium Hydroxide: A Comparison of
Specially Designed Paste Carrier Technique with Other Techniques. BMC Oral Health, 2013; 13: 52.

68. • The duration of dressing with calcium hydroxide is
dependent upon the objective of dressing.
68
Antibacterial dressing
Incompletely formed
apices
Weeping canal
7 days
9 months-24 months
14 days
• There is no definitive guidance on the duration of dressing in case of dental
trauma and root resorption. These should be gauged on the basis of the
requirement of the case.

69. 8.)Root canal sealers
• The two most important reasons for using calcium hydroxide as a
root-filling material :
1.) Stimulation of the periapical healing (Osteogenic & cementogenic)
2.) Antimicrobial effects.
• This is exerted via the leaching of calcium and hydroxyl ions to
surrounding tissues .
• The role of root canal sealers is to fill gaps; therefore, solubility,
leakage & adhesion are prime concerns. 69

70. 1. Calciobiotic Root Canal Sealer-
• 14% of Calcium Hydroxide
and ZnO eugenol
• Setting time- 3days
• Water sorption- 0.4%
2. Sealapex -
• Setting time-3 weeks
• Water sorption- 1.4%
70
3. Apexit Plus-
• Contains- Calcium hydroxide, disalicylate,
water
• Hard setting ability, Biological tolerance
• Easy to mix and radio opaque
4. Vitapex-
• Iodoform (bactericide) is released to supress
bacteria

71. Calcium hydroxide points
• Calcium hydroxide containing Gutta Percha Points is used for
short term medications first by Roeko in Germany.
• The constituents of calcium hydroxide plus points include 52%
calcium hydroxide, 42% gutta-percha, sodium chloride,
surfactant, and colouring agents.
• A drop of sterile water can be used to initiate ion release.
However sufficient fluid flows between canal walls from dentinal
tubules and apical region.
71

72. • These points are flexible as well as firm the can be easily
introduced and removed even after several months.
• CHP can provide active ions for 1-3 weeks after which it has to be
replaced or removed.
72

73. • Effectiveness of calcium hydroxide plus points and chlorhexidine
active points against Enterococcus faecalis by agar diffusion test:
An in-vitro study
(Journal of Restorative Dentistry / Vol - 1 / Issue - 1 / Jan-Apr 2013)
73
1. Chlorehexidine active points obtained the highest
antimicrobial activity compared with other medicament.
2. Combination of both shows higher antimicrobial activity
when compared with calcium hydroxide plus points alone.
3. Calcium hydroxide plus points reveals significantly less
antimicrobial activity.
4. Chlorehexidine points can be the medicament of choice since
they are more effective against the microbes that are
routinely found in the infected root canals.

74. • Calcium hydroxide–induced resorption of deciduous teeth: A
possible explanation. (Dental Hypotheses Jul-Sep 2012 / Vol 3 | Issue 3)
- Results in the development of chronic pulpal inflammation &
internal root resorption.
Hypothesize that odontoclasts cause resorption of primary teeth on the
placement of CaH and this odontoclastogenesis could be as a result of:
1. CaH-induced chronic inflammatory response which could
influence the macrophages to fuse and form odontoclasts
- either through direct stimulation
- or indirectly by stimulating stromal odontoblasts/ fibroblasts.
2. A pre-existing predilection of progenitor cells in deciduous tooth
pulp to form odontoclasts.
3. The loss of predentin could expose mineralized dentin to
odontoclasts, making it more vulnerable to resorption.
74

75. 75

76. 76
Proposed mechanisms for lack of dentine bridge formation in
deciduous tooth pulp in presence of calcium hydroxide (CaOH2)

77. Removal of Ca(OH)2 from canals
• Prior to obturation, the canal space must be thoroughly debrided
of calcium hydroxide as residual calcium hydroxide can
negatively influence the outcome of obturation.
77
Remnants of Ca(OH)2 can hinder the penetration of sealers
into the dentinal tubules (Calt & Serper 1999)
Hinder the bonding of resin sealers to dentine
Increase the apical leakage of root fillings (Kim & Kim 2002)
Potentially interact with zinc oxide eugenol sealers and make
them brittle and granular (Margelos et al. 1997).

78. • Thorough cleaning of root canal system can be achieved by
delivering effective irrigation, solution activation as well as
direct contact with all canal walls especially in the apical
third.
• NaOCl + EDTA alone has not been sufficient to eliminate
calcium hydroxide (chitosan & calcium chelators such as
citric acid, maleic acid & peracetic acid)
• Several techniques have been proposed to remove the
Ca(OH)2 dressing from the root canal system, including the
use of endodontic hand files, sonic activation, passive
ultrasonic irrigation, CanalBrush System & (NiTi) rotary
instruments. 78
Bevel needle
Side vented
Canal brush
XP endo finisher
Vibringe

79. • PUI has been found to produce cleaner canals. This is
accomplished with a small file vibrated in a previously shaped
root canal to produce acoustic streaming that transfers its energy
to the irrigant inside the canal.
• The 10% citric acid performed better in comparison to 17%
EDTA solution in removal of Metapex. This probably could be
because of the reason that EDTA chelates calcium ions in water,
but citric acid is able to penetrate the silicone oil better in
comparison to EDTA and chelates the calcium ions.
79
J Conserv Dent. 2017 Jan-Feb; 20(1): 25–29.

80. • However, 0.2% chitosan performed better than 17% EDTA and
20% citric acid solution in the removal of both aqueous-based
and oil-based Ca(OH)2
• Nandini et al. showed that use of oily substances as propylene
glycol associated with Ca(OH)2 have higher tensile strength when
compared to aqueous vehicles like distilled water & that the
association of calcium with distilled water vehicle more fluid with
ultrasonic removal, compared to oily vehicle.
80

81. Synergism between Ca(OH)2 & NaOCl.
• Hasselgren et al. (1988) studied dissolution of necrotic porcine
muscle tissue and reported that a paste of Ca(OH)2 powder and
water was capable of dissolving tissue after 12 days of exposure.
Furthermore, they reported an enhancement of the tissue-dissolving
capability of sodium hypochlorite when the tissue was pretreated
with Ca(OH)2 for 30 min, 24 h and 7 days.
• Wadachi et al. (1998) evaluated the tissue-dissolving ability of NaOCl
and Ca(OH)2 in a bovine tooth model and reported that the amount
of debris was reduced remarkably in teeth treated with NaOCl for
>30 s or Ca(OH)2 for 7 days. However, the combination of Ca(OH)2
and NaOCl was more effective than the separate treatments. 81
International Endodontic Journal, 44, 697–730, 2011

82. Ca(OH)2 and chlorhexidine
• Chlorhexidine is a cationic biguanide whose optimal antimicrobial
activity is achieved within a pH range of 5.5–7.0 (Athanassiadis et al.
2007).
• Alkalinizing the pH by adding Ca(OH)2 to CHX will lead to
precipitation of CHX molecules, thereby decreasing its effectiveness
(Mohammadi & Abbott 2009).
• It has been demonstrated that the alkalinity of Ca(OH)2 when mixed
with CHX remained unchanged (Haenni et al. 2003). Therefore, the
usefulness of mixing Ca(OH)2 with CHX still remains unclear and
controversial.
• When used as an intracanal medicament, CHX was more effective
than Ca(OH)2 in eliminating E. faecalis from inside dentinal tubules.
82

83. 83
-Initially bactericidal effect then
bacteriostatic
-Promotes healing & repair
-High pH stimulates fibroblasts
-Stops internal resorption
-Neutralizes low pH of acids
-Inexpensive & easy to use.
-Does not exclusively stimulate
dentinogenesis
-Asso. with primary tooth resorption
-Degrades upon tooth flexure
-Does not adhere to dentin or resin
restoration
-Does exclusively stimulate reperative
dentin

84. Conclusion
Calcium hydroxide is widely used material in endodontic
treatment due to its high alkalinity and bactericidal
properties. It is a material which is readily available, simple
to prepare and restorable. Calcium hydroxide is still a
material of choice which is widely being used for various
reasons in Endodontics.
84

85. References
• Chettinad Health City Medical Journal 2016; 5(1): 30 - 33
Review Article Calcium Hydroxide in Dentistry .
• J. Appl. Oral Sci. vol.11 no.4 Bauru Oct./Dec. 2003: Journal of
Applied Oral Science
• International Endodontic Journal, 44, 697–730, 2011:
Calcium hydroxide in endodontics and dental traumatology
Mohammadi & Dummer.
• International Endodontic Journal, 32, 361±369, 1999
Mechanisms of antimicrobial activity of calcium hydroxide: a
critical review, J. F. Siqueira Jr1 & H. P. Lopes.
85

86. • Hindawi Publishing Corporation Mediators of Inflammation
Volume 2015; Michel Goldberg, Akram Njeh, and Emel Uzunoglu.
• Calcium hydroxide-induced resorption of deciduous teeth: A
possible explanation. Dental Hypotheses Jul-Sep 2012 / Vol 3 |
Issue 3, G. R. Ravi, R. V. Subramanyam1.
• Retrievability of calcium hydroxide intracanal medicament with
three calcium chelators, ethylenediaminetetraacetic acid, citric
acid, and chitosan from root canals: An in vitro cone beam
computed tomography volumetric analysis, J Conserv Dent. 2017
Jan-Feb; 20(1): 25–29.
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