Calcium hydroxide in pediatric dentistry

Calcium hydroxide and its role in
pediatric dentistry
By Dr. Lilavanti Vaghela
MDS in Pediatric and Preventive Dentistry

Content
✓ Introduction
✓ History of calcium hydroxide
✓ Characteristic of calcium hydroxide
Chemical Composition and Activity
Physical Properties
✓ Classification of calcium hydroxide
✓ Different vehicles
✓ Mechanism of action of calcium hydroxide
✓ Advantages - Diadvantages
✓ Clinical applications of calcium hydroxide
• Calcium hydroxide as a cavity liner
• Calcium hydroxide when used in vital-Non vital pulp therapy
a. Indirect Pulp Capping
b. Direct Pulp Capping
c. Pulpotomy
d. pulpectomy
e. Apexification

✓ Calcium hydroxide as a intracanal medicaments
✓ As a constituent of a root canal sealer
✓ Other applications of calcium hydroxide
a. Canals with exudates
b. Horizontal root fracture
c. Perforations
d. Root resorption
✓ Coclusion
✓ Referances

Introduction
• The overriding goal of pediatric dentistry is to determine what is best for child at that moment
and what is best for the adult into whom the child will eventually grow.
• This goal can be accomplished by preventing disease, relieving pain, improving mastication
efficiency, enhancing speech, and improving appearance.
• Because many of these objectives require the replacement or alteration of tooth structure, the
main challenges for centuries have been the development and selection of biocompatible,
long-lasting, direct-filling tooth restoratives and indirectly processed prosthetic materials that can
withstand the adverse conditions of the oral environment.
Anusavice. Phillips’ Science of Dental Materials. 11th Ed. Mosby. 2006;1:1-3.

Anusavice, has broadly classified dental materials as
1) Preventive materials
2) Restorative materials
3) Auxiliary materials
1) Preventive dental materials
include pit and fissure sealants; sealing agents that prevent leakage; materials that are
used primarily for their antibacterial effects; and liners, bases, cements and restorative
materials that are used primarily because they release fluoride, chlorhexidine, or other
therapeutic agents used to prevent or inhibit the progression of dental caries.
Anusavice. Phillips’ Science of Dental Materials. 11th Ed. Mosby. 2006;1:1-3.

2) Restorative materials
consist of all synthetic components that can be used to repair or replace tooth
structure, including primers, bonding agents, liners, cement bases, amalgams,
resin based composites, compomers, hybrid ionomers, cast metals, metal-cera
mics, ceramics, and denture polymers.

3) Auxiliary dental materials
• are substances that are used in the process of fabricating dental prostheses and
appliances but that do not become a part of these devices.
• These includes acid-etching solutions, impression materials, casting investments, gypsum
cast and model materials, dental waxes, acrylic resins for impression and bleaching trays,
acrylic resins for mouth guards and occlusion aids, and finishing and polishing abrasives.

• Calcium Hydroxide is one of the wonderful materials that basically falls into preventive as
well as restorative material categories, as it has been used in variety of purposes since its
introduction to dentistry in the early part of the twentieth century.
• Its dental use relates chiefly to its antibacterial properties and the ability to induce repair
and to stimulate hard-tissue formation.
• Dental application of calcium hydroxide include as a Dentin desensitizing agent, Pulp cap
technique- indirect as well as direct; As a liner & base; in Apexogenesis and Apexification;
in a Root Canal Sealer; and as a endodontic intracanal medicament. Moreover Hard
tissue induction in root fractures, root perforation & root resorption.

Calcium hydroxide is a strong alkali, which can be formed by the reaction of
calcium oxide. If the oxide is treated with only sufficient water to make it crumble
to a fine, white, dry powder slaked lime is produced.
Synonyms
✓ calcium hydrate
✓ caustic lime
✓ hydrated lime
✓ lime hydrate
✓ slaked lime

History
• Calcium Hydroxide has been used for long time for dental purposes.
• Despite of the numerous attempts to replace it by other substances, calcium has
extraordinary role in dentistry, both in pure form and in combination with other
substances.
• During the last 200 years there have been many changes in the rationale governing the
treatment of the exposed dental pulp as it was long ago observed that an exposed
pulp healed with great difficulty, if at all.
• The earliest account of pulp therapy was way back in 1756, when Phillip Pfaff packed a
piece of gold over an exposed vital pulp to promote healing.
Stanley HR. Pulp capping: conserving the dental pulp – can it be done? Is it worth? Oral Surg Oral Med Oral Pathol
1989;68:628-639.

• Until Hermann’s introduction of a material so eminent, which marked a new era in
pulp therapy, when he demonstrated that a Calcium Hydroxide formula called
Calxyl® induced dentinal bridging of the exposed pulpal surface.
• Since then the emphasis has shifted from the “doomed organ” concept of an
exposed pulp to one of hope and recovery.
Stanley HR. Pulp capping: conserving the dental pulp – can it be done? Is it worth? Oral Surg Oral Med Oral Pathol
1989;68:628-639.

Lime
• General term for calcium containing oxides or hydroxides.
• The rocks and minerals from which this material derived is called Calcium carbonate.
• Burning (calcinations) converts them into highly caustic Quicklime, CaO (Calcium Oxide).
• Subsequent addition of water, convert it into Slaked lime or hydrated lime, Ca(OH)2
(Calcium Hydroxide). The process is called Slaking lime.
• Slaked lime is useful to prevent bleeding, to cicatrizing, to heal wound and cuts,
and also to soothe burned skin.
Duffin CJ, Moody RTJ, Gardner C. Thorp ; A history of geology and medicine; 4:72.

• Calcium Hydroxide, an old remedy, also recommended for the treatment of
“Fistula dentalis” in 1838 by Nygren.
• But Calcium Hydroxide gained wide acceptance after landmark study by Bernhard
W. Hermann, 1920 as he first time used Calcium Hydroxide to fill root canals.
• He clearly demonstrated the antibacterial effect of calcium hydroxide in infected
root canals without any adverse reactions.
• The aim of Hermann was not to find a new agent for direct pulp capping or
pulpotomy but a method for “biological root canal treatments”. The material
Hermann used was Calxyl®, manufactured by Otto & Co., Frankfurt, Germany.
Hermann B. Kalziumhydroxid Als Mittel Zum Behandeln Und Füllen Von Zahnwurzelkanälen. Wurzburg, Disserta
tion 1920.

• To prove biocompatibility of Calcium Hydroxide, Hermann performed the first
successful vital pulpotomy around 1930, and could show that it is well suitable to
keep the pulp tissue vital without impairing its function and to induce hard tissue
formation.
• In 1938, Teuscher and Zander provided experimental results on the use of a paste of
Calcium hydroxide to cover amputed pulps.
• The actual reported technique of pulpotomy using calcium hydroxide was described
by Zander and Law in 1942, and histological evidence of repair with formation of a
new layer of odontoblasts and a secondary irregular dentin barrier has been given by
Zander and Glass in 1949.
Zander HA, Law DB. Pulp management in fractures of young permanent teeth. J Am Dent Assoc 1942;29:737-741.

• Munch in 1931 made the suggestion to mix “lime” with vitamins for pulp
capping.
• The agent was offered on the market as Pulpatekt®, and was a compound
made of different calcium salts, vitamins and chlorophenol camphor for
disinfection.
• The add-on of chlorphenol camphor proved to be adverse, so it was later
omitted.
• Instead, sterilized bone marrow of calves embryo was added.

• Flohr in 1936 also introduced a preparation called Vitapulp®.
• He was afraid that Hermann’s calcium hydroxide could induce tissue necrosis
due to the alkaline pH value.
• By adding calcium salts, Flohr lowered the pH value of calcium hydroxide
and mixed it with dentin chips.
• To avoid direct contact and pressure to the pulp tissue Flohr additionally
covered the exposure with a small piece of blotting paper before Vitapulp
was applied.

• A disadvantage of calcium hydroxide is the fact that it is an aqueous non-hard-setting
paste.
• Hence, Champion in 1941 was convinced that calcium hydroxide was not suitable as a
definitive root canal filling material as suggested by Hermann.
• Therefore, Champion developed a hard-setting calcium hydroxide preparation called
Endoxyl® in 1941.
• Endoxyl® was composed of two pastes containing calcium hydroxide, calcium gluconate
and calcium glycerin phosphate, which could be used for root canal fillings as well as
direct pulp capping.

• In 1953 Castagnola compared the results of direct pulp capping with materials mainly from
the 1930s and 1940s and calcium hydroxide using histological evaluations and comparing
previous data from the literature.
• In all comparisons, calcium hydroxide clearly had the best results.
• Even Ingle has stated that historically, most effective capping material is calcium hydroxide.

• Eastlick recommended calcium hydroxide for use with exposed pulps in teeth with immature
apices in 1943.
• The use of calcium hydroxide for apexification was popularized in the early 1960s by Dr. Alfred
L. Frank in his presentation at the AAE meeting in 1964, and his detailed applications that
became known as the "Frank Technique" were published in 1966.
• Heithersay has provided a rather extensive treatise on the wide range of applications for
calcium hydroxide.

• Use of sterile water as a vehicle with calcium hydroxide powder for root canal dressing
was described by Matsumiya & Kitamura in 1960.
• Crabb in 1965 was the first to use distilled water with calcium hydroxide powder
treatment of large periapical lesions.
• An old suggestion proposed by Yacometti 1952 was to add penicillin to a calcium hydro
xide-distilled water paste to be used as a pulp capping material.

• Steiner et al. in 1968 first use calcium hydroxide with glycerine as it is hygroscopic
in nature, glycerine is very useful as moistening substance furthermore it is nontoxic
and is used as an intracanal lubricant.
• Siqueira & Uzeda in 1996 added camphorated parachlorophenol to a calcium hydro
xide + glycerine paste in order to extend its antibacterial spectrum against some
species of obligate and facultative anaerobic bacteria.

• Berck in 1950 use calcium hydroxide methylcellulose paste for direct pulp capping
later on which is commercially available as Pulpdent®.
• Maisto & Capurro in 1964 introduced a paste composed of equal volumes of
calcium hydroxide powder and iodoform mixed with a 5% aqueous solution of
methylcellulose.
• Laurichesse in 1980 added two drops of camphorated parachlorophenol in the a
bove preparation and Giro et al. in 1993 proposed the use of carboxymethylcellul
ose instead of methylcellulose.

• Leonardo et al. in 1976 introduced a paste containing calcium hydroxide with
polyethyleneglycol which contain barium sulphate for radiopacity.
• Later Leonardo & Leal in 1991 replaced the barium sulphate by zinc oxide and it
is commercially available as Calen®
• Furthermore, 0.15 mL of camphorated parachlorophenol was added to the paste
when used in cases of infected root canals; this paste is now a proprietary brand –
Calen + camphorated parachlorophenol®
• Yoshiba et al. in 1994 proposed a new formulation, adding a tricalciumphosphate
to the calcium hydroxide powder and saline for capping amputed pulps.

• Sazak et al. in 1996 have suggested adding Ledermix (Lederle Lab., Muènchen, Germany)
to a calcium hydroxide-saline paste to be used after pulpotomy with the purpose of
reducing postoperative pain and inflammation.
• The calcium hydroxide containing a pulp capping agent, Dycal® (Dentsply-Caulk,
Milford, DE), also became popular since 1970s to till date.

Dycal I Dycal II Dycal III
Dycal® I had a relatively high water
solubility and a relatively low
compressive strength.
• In order to increase the compress
ive strength and decrease the
solubility of Dycal® I, the manufa
cturer added more polymer to
the material.
• lower the water solubility from 6.
7 to 1-2% per 24 h and increased
the compressive strength from
2400 to 3700-4700 psi.
• However, the compressive strengt
h of Dycal® II was still low
enough that it might fail during
amalgam condensation or during
function.
• manufacturer to reformulate Dyca
l® by adding a urethane dimetha
crylate resin capable of being
light- cured with visible light.
• This led to a large increase in
compressive strength (from 3700-
4700 for Dycal® II to 12,000-15,0
00 psi for Dycal® III) and a
concomitant decrease in water
solubility, from 1-2% per 24 h to
<0.5%.
Stanley HR, Pameijer GH. Pulp capping with a new visible- light-curing calcium hydroxide composition (Prisma V
LC Dycal). Oper Dent 1985;10:156-163.

• Vitapex® (Neo Dental Chemical Products Co. Ltd, Tokyo, Japan). This paste was introduced
by Kawakami et al. in 1979. It is composed of calcium hydroxide, iodoform, silicone oil and
other substances.
• Metapex® (Meta Biomed Co Ltd, Korea), calcium hydroxide with iodoform is
used now a days widely as a root canal filling material, as sealer, weeping canals.
Its success rate is more than 90%.
• Kalaskar R and Damle SG in 2004 evaluated the potential of lyophilized freezed
dried platelet with calcium hydroxide as pulpotomy agent and found out that it
had 100 percent success.

Mode of supply
✓ Can be supplied in powder form – powder can be mixed with distilled water,
saline solution to form a thick paste and applied as such.
✓ Can be supplied as two paste system, one base paste another catalyst paste.
✓ Can be supplied as single paste (visible light).

Characteristic of calcium hydroxide
Chemical Composition and Activity
• Limestone is a natural rock mainly composed of calcium carbonate (CaCO3) which forms
when the calcium carbonate solution existing in mountain and sea water becomes
crystallized.
• The combustion of limestone between 900 oC and 1200 oC causes the following chemical
reaction:
• The calcium oxide (CaO) formed is called `quicklime' and has a strong corrosive ability.
• When calcium oxide contacts water, the following reaction occurs:
•
CaCO3 → CaO + CO2
CaO + H2O → Ca(OH)2
Farhad A, Mohammadi Z. Calcium hydroxide: a review. Int Dent J 2005;55:293–301.

• It is a white odourless powder with the chemical formula Ca(OH)2
• molecular weight → 74.08
• It has low solubility in water → (around 1.2 g/L at 25oC), which decreases with a rise in
temperature
• It has been demonstrated that the dissociation coefficient of Ca(OH)2 → 0.17, which
controls the slow release of both calcium and hydroxyl ions. This low solubility is a
useful clinical characteristic as an extended period is necessary before it becomes
solubilised when in direct contact with fluids from vital tissues.

• The pure powder has a high pH →(approximately 12.5–12.8) and is insoluble in alcohol.
• The material is chemically classified as a strong base, its main actions come from the
ionic dissociation of Ca2+ and OH- ions and their effect on vital tissues, generating the
induction of hard-tissue deposition and being antibacterial.
• According to Rehman et al., Ca(OH)2 dissociates into calcium and hydroxyl ions on
contact with aqueous fluids.

Solubility
• The solubility of calcium hydroxide bases has been measured in several solvents for
various periods of immersion.
• For various commercial products, values ranged
From 0.4% to 7.8% in → distilled water at 37oC for 24 hours,
from 0.1% to 6.2% in → 35% phosphoric acid for 60 seconds,
from 0.3% to 1% in → ether for 10 seconds.
• Some solubility of the calcium hydroxide is necessary to achieve its therapeutic
properties, although an optimum value is not known.
Craige RG, Powers JM; Craige Restorative Dental Material; 11th Ed 20:625-626.

Thermal properties
• Calcium hydroxide bases may provide some thermal insulation to the pulp if
used in sufficiently thick layers. Practically, thermal protection should be
provided by the overlying high-strength base.
Material thickness
• Dycal manufacturing company has described that material thickness should
be approximately 0.8 mm-1 mm
Dycal Manufacturing Company Paper, Dentsply, Chaulk.

Physical properties
Compressive Strength
• 7 minutes : 3.8 to 7.6 MPa to 550 psi.
• 30 minutes: 4.8 to 6.2 MPa to 750 – 900 psi
• 24 hours: 8.3 to 10.3 MPa or 1200 – 1500 psi
• Tensile strength: 10 MPa
• Modulus of elasticity: low -0.37 Gpa/m2
• pH: high alkaline: 9.2 to 11.7
• Setting time: 2.5 – 5.5 minutes.

Compressive Strength
(MPa)
Tensile Strength (MPa) Elastic Modulus (GPa)
Calcium hydroxide (self
cured)
12-26 1 0.4
Calcium hydroxide (light
cured)
96 38 -

Properties of Various Dycal®
Dycal® I Dycal® II Dycal® III
Water solubility (% in 24 h) 6.76% 1-2% <0.5%
Acid solubility (% in 37% H2PO4 in
60 s)
2.65% 2.0 – 2.5 % <0.18
Compressive strength (psi) 2400 3700-4700
12,500-15,000
pH (24 h) 11.4 9-10 9-10

Composition
Acidic paste
• Alkyl salicylate (iso-butyl salicylate or 1-methyl triethylene salicylate)
• Inert fillers – titanium oxide 12-14%
• Radiopacifer – barium sulphate 32-35%
• Calcium tungstate or calcium sulphate 14-15%
Basic paste
• Calcium hydroxide 50-60%
• Zinc oxide 10%
• Zinc stearate 0.5%
• Ethylene toluene sulphonamides and paraffin oil 39.5%

• Alkyl salicylate is dysfunctional chelating agent.
• On mixing this with paste containing zinc oxide and calcium hydroxide, amorphous
calcium disalicylate is formed.
• The sulphonamide compound used in the paste is present merely as a carrier.
• Some cements contain paraffin oils instead of sulphonamides.
• These elements are more hydrophobic and release their calcium hydroxide more slowly.
• Some commercially available calcium hydroxide products are Dycal, life, Hydrex,
care VLC, Dycal (light cured)

Light Cured paste formulation
• Dimethacrylate eg. Bis GMA
• Hydroxy ethyl methacrylate (HEMA)
• Calcium hydroxide
• Polymerizing activator
• Barium sulphate
✓ The purpose of HEMA is to produce a relatively hydrophilic polymer, which can absorb
water and release, calcium hydroxide to create an alkaline environment.

Composition of Self Cure Dycal and Light Cure Dycal®
Dycal® Visible Light Cure Dycal®
Base paste Catalyst paste Calcium hydroxide
Calcium tungstate Calcium hydroxide Calcium hydroxyapatite
Zinc oxide Zinc oxide Barium sulphate
Disalicylate ester of 1,3
butylene glycol
Titanium dioxide Fluorides
Resin matrix (UDMA)

Classification
Calcium hydroxide can be classified as certain ways,
(1) Based on setting mechanism
(2) Based on type of vehicle used
(3) Based on material added

(1) Based on setting mechanism → setting
→non setting
(2) Based on type of vehicle used
Aqueous vehicle (Eg. Water, saline dental anesthetic, ringers solution, aqueous sus
pension of methylcellulose).
Viscous vehicle – (ex. glycerine, polyethylene glycol and propylene glycol )
Oily vehicles – (eg. Olive oil, oleic acid, linoleic and isosteric acid)
(3) Based on material added
eg. Monomer, varnish, oil, acid etc.
Foreman PC, Barnes IE. A review of calcium hydroxide. Int Endod J 1990; 23:283-297

Setting materials
• The therapeutic properties of the setting calcium hydroxide materials are related to their pH.
• It is also dependent on the levels of unbound calcium and hydroxyl ions that remain after
the material has set, and it follows that the egress of ions from the set material will lead to a
reduction of its mass.
• One factor which increases the availability of the hydroxyl ion is the hydrophobic nature of the
material.
• The more hydrophobic, the less likely is diffusion to occur,
Eg, Hydrex®, was more hydrophobic than Dycal® due to the presence of a paraffin
solvent which prevented the diffusion of water into the set material.
Based on setting mechanism

• An additional factor to be considered in the dissolution of calcium hydroxide is
the effect of bacteria, associated with microleakage, on the set material.
• Watts & Paterson established that bacteria may be present in contact with
calcium hydroxide. This could lower the pH of the material by converting it to
calcium carbonate, and might explain why early Dycal® preparations seemed to
disappear from beneath permanent restorations.
Watts A, Paterson RC. Pulp-capping studies with analar calcium hydroxide and zinc oxide-eugenol. Int Endod J 1987;20:169-176.

There are two basic setting mechanisms
(i) The two-paste system: It is based on the reaction between calcium and zinc ions
and a salicytate chelating agent, and is accelerated by the presence of water.
(ii) The single-paste system: It utilizes the polymerization of a dimethacrylate by
means of light, and is represented by Prisma VLC Dycal®.
• A potential disadvantage of the dimethacrylate systems, when used as a base beneath
composite restorations, is their adherence to the composite material and subsequent
withdrawal from the base of the cavity during polymerization.

Non-setting materials
• calcium hydroxide may be applied either dry, or using distilled water as the vehicle.
• Clinically, this has the disadvantage that the mixture forms a slurry which may separate
and can be difficult to manipulate within the root canal by puddling; alternatively, it may
be mixed into a very thick paste which can be placed into the root canal with an
amalgam carrier and condensed with root canal pluggers.
• Proprietary brands overcome this problem by using methyl cellulose as a vehicle, with
varying amounts of water. This results in homogeneous pastes of varying consistency,
with good handling properties.
• Other admixtures have been suggested, such as local anaesthetic solution, camphorated
monochlorphenol (CMCP), beechwood creosote, Ledermix and radiopacifiers.

Foreman PC, Barnes IE. A review of calcium hydroxide. Int Endod J 1990; 23:283-297
Non Setting Calcium Hydroxide Materials
Material Vehicle
Analar calcium hydroxide Water
Pulpdent® Methyl cellulose
Hypo-Cal® Methyl cellulose
Reogan® Methyl cellulose

BASED ON TYPE OF VEHICLE
• When calcium hydroxide powder is mixed with a suitable vehicle, a paste is formed and,
because the main component is calcium hydroxide, Maisto classified these formulations
as alkaline pastes because of their high pH.
These pastes should have the following characteristics:
1. Composed mainly of calcium hydroxide which may be used in association with other
substances to improve some of the physicochemical properties such as radiopacity, flow
and consistency;
2. Non-setting;
3. Can be rendered soluble or resorbed within vital tissues either slowly or rapidly depending
on the vehicle and other components.
4. May be prepared for use at the chairside or available as a proprietary paste;
5. Within the root canal system they are used only as a temporary dressing and not as a
definitive filling material.
Leonardo MR, Leal JM, Simoes Filho AP. Endodontia tratamento dos canais radiculares. Sao Paulo:Panamericana 1982.

• The easiest method to prepare a calcium hydroxide paste is to mix calcium hydroxide
powder with water until the desired consistency is achieved.
• However, Leonardo et al. stated that a paste prepared with water or other hydrosoluble
non-viscous vehicle does not have good physicochemical properties, because it is not
radio-opaque, is permeable to tissue fluids and is rendered soluble and resorbed from
the periapical area and from within the root canal.
• For these and the following reasons, Leonardo et al. recommended the addition of
other substances to the paste:
1. To maintain the paste consistency of the material which does not harden or set;
2. To improve flow;
3. To maintain the high pH of calcium hydroxide;
4. To improve radiopacity;
5. To make clinical use easier;
6. Not to alter the excellent biological properties of calcium hydroxide itself.

• calcium hydroxide paste for use in pedodontics is composed of the powder,
a vehicle and a radiopacifier.
• Other substances may be added to improve physicochemical properties or
the antibacterial action.

Types of vehicles and their importance
• Actions of calcium hydroxide will be progressed by the ionic dissociation in Ca2+ and OH- ions.
• The vehicle plays a most important role in the overall process because it determines the velocity
of ionic dissociation causing the paste to be solubilized and resorbed at various rates by the
periapical tissues and from within the root canal.
According to Fava, the ideal vehicle should:
1. Allow a gradual and slow Ca2+. and OH- ionic release;
2. Allow slow diffusion in the tissues with low solubility in tissue fluids;
3. Have no adverse effect on the induction of hard tissue deposition.
Fava LRG. Calcium hydroxide paste. considerations about your job in endodontics clinic. Revista Paulista Odontol 1991;13:36-43.

✓ When calcium hydroxide is mixed with one of these substances, Ca2+ and OH- are rapidly released.
✓ This type of vehicle promotes a high degree of solubility when the paste remains in direct contact
with the tissue and tissue fluids, causing it to be rapidly solubilized and resorbed by macrophages.
✓ The root canal may become empty in a short period, delaying the healing process.
• Water
• saline,
• dental anaesthetics with or without a vasoconstrictor,
• Ringer's solution,
• aqueous suspension of methylcellulose or carboxymethylcellulose
• anionic detergent solution.
Aqueous vehicle

Water
• The easiest method to prepare a calcium hydroxide paste is to mix the powder with water.
• However, the literature describes different types of water with which to prepare the paste,
including sterile water, distilled water, sterile distilled water, bidistilled water and sterile
bidistilled water.
• Usually this paste is prepared on a sterile glass slab with a sterile spatula.
• The powder is mixed with the liquid until the desired consistency is achieved.
• The paste is carried into the root canal.

• chemical characteristics of such a paste were evaluated by different authors,
eg, pH (Conrado et al. 1965, Leonardo et al. 1992),
ionic dissociation (Leonardo et al. 1992)
diffusion through dentine (Leonardo et al. 1993a, Esberard et al. 1996).
• The antibacterial effect was studied by Martins et al. (1979), Bremer (1980) and Di Fiore et al. (1983),
whilst the solvent action was evaluated by Hasselgren et al. (1988).

Sterile water
• First evaluated in apexification procedures in dog teeth (Vojinovic & Srnie 1975) and as
a dressing in infected root canals (Matsumiya & Kitamura 1960).
In humans indication of this paste:
• direct pulp capping (Sommer et al. 1975, Horsted et al. 1985),
• pulpotomy and apexogenesis (Corpron & Dowson 1970, Goldman 1974)
• apexification procedures (Erdogan 1997),
• an apical plug before gutta-percha filling in non-vital teeth with an open apex
(Michanowicz & Michanowicz 1967)
• internal resorption with perforation of the dentinal wall (Barclay 1993).
Fava LRG, Saunders WP. Calcium hydroxide pastes: classification and clinical indications (Review). Inte
rnational Endodontic Journal, 32, 257±282, 1999.

Distilled water
• First used by Crabb (1965) → treatment of large periapical lesions
Pastes containing this vehicle were chemically evaluated for:
• pH → (Conrado et al. 1965, Leonardo et al. 1992, Fuss et al. 1996), ionic dissociation (Leonar
do et al. 1992, Marques et al. 1994, Simon et al. 1995, Felippe 1998),
• tissue solvent action → (Morgan et al. 1991, Yang et al. 1995)
• antibacterial effect → (Siqueira & Uzeda 1997)

It was evaluated for its effect,
• on dentine (Holland et al. 1978a),
• direct pulp capping material (Ogawa et al. 1974, Holland et al. 1980a, 1982),
• temporary dressing material after vital pulp extirpation (Sekine et al. 1963a, Holland et al. 1978)
• apexification procedures (Binnie & Rowe 1973)
• chronic periapical lesions in dogs (Holland et al. l979b)
• iodoform or bismuth carbonate should be added to improve thradiopacity of the paste (Holland
et al. 1981, Rezende 1982).
• An old suggestion proposed by Yacometti (1952) was to add penicillin to a calcium hydroxide-
distilled water paste to be used as a pulp capping material.

Sterile distilled water
• First evaluated in human direct pulp capping (Patterson & Van Huysen 1954),
• in apexification procedures (Wechsler et al. 1978).

Bidistilled water
• According to Laurichesse (1980) →Albou who first used bidistilled water as the vehicle
of the paste in normal clinical cases.
Sterile bidistilled water
• This vehicle was recommended by Breillat et al. (1983) for human apexogenesis
and apexification procedures.

Saline or sterile saline
• According to the United States Pharmacopeia (1989) saline is prepared by dissolving 9 g of sodium
chloride in water to make 1000 mL.
Following charachteristic was evaluated:
✓ pH (Anthony et al. 1982, Estrela et al. 1995b, Peniche et al. 1996),
✓ ionic dissociation (Foster et al. 1993, Marques et al. 1994, Estrela et al. 1995b, Sim
on et al. 1995, Gomes et al. 1996),
✓ tissue solvent action (Wakabayashi et al. 1995),
✓ antibacterial effect (Safavi et al. 1985, Stuart et al. 1991, Barbosa et al. 1995, Estrel
a et al. 1995a, Siqueira & Uzeda 1996, Sydney 1996),
✓ apical microleakage (Porkaew et al. 1990, Siqueira & Fraga 1995) and some
✓ methods to remove the paste from within the root canal (Guignes et al. 1991).

Clinically, it was evaluated in,
• non-vital immature teeth (Cvek 1972, Cvek & Sundstrom 1974, Gallagher & Mourino 1979)
• perforations (Bogaerts 1997)
• internal resorption at the site of an intra-alveolar root fracture (Cvek 1974)
• external inflammatory root resorption (Rabie et al. 1988),
• luxated non-vital teeth (Cvek 1992)
• antibacterial dressing in infected teeth (Barbosa et al. 1995)
• infected teeth with associated acute or chronic periodontitis (Orstavik et al. 1991)
• non-vital infected teeth with associated cutaneous sinus tract (Foster et al. 1992)
• endodontic retreatment after endodontic and surgical failures (West & Lieb 1985) and as a dressing
after partial pulpectomy (Engstrom & Spangberg 1967).

Anaesthetic solutions
• Anaesthetic solutions, with or without a vasoconstrictor, have been used as the vehicle of the
paste because these solutions are readily available, sterile and easy to handle.
• These solutions have an acid pH, but when mixed with the calcium hydroxide powder, the final
paste has a high pH which is maintained over time.
According to (Stamos et al. 1988, Marques et al. 1994, Prokopowitsch 1994, Estrela et al. 1995b,
Fuss et al. 1996, Peniche et al. 1996 → they promote a rapid ionic release

This paste has been indicated for,
• human apexification procedures by Goldman (1974), Taintor (1977),
• pulp capping material by Armstrong & Hoffman (1962).

Ringer's solution
• According to the United States Pharmacopeia (1989), this solution has sodium chloride (8.6 g),
potassium chloride (0.3 g), calcium chloride (0.33 g) and water to 1000 mL.
• First described by Granath (1959) in e in cases of traumatic injuries.
• Chemically, this paste was evaluated for alterations in the pH of dental structures when used as
a temporary dressing (Tronstad et al. 1981).

Clinically, it has been evaluated in,
• indirect pulp capping (Nyborg 1955),
• in apexification procedures (Cvek 1972)
• as a temporary dressing both after vital pulpectomy (Nyborg & Tullin 1965,
Stromberg 1969)
• in non-vital teeth (Cvek 1976)
• treatment of post-traumatic sequelae such as luxation and replantantion
(Cvek 1973, 1989).

Distilled water Crabb,1965
Bidistilled water Albou,1980
Sterile bidistilled water Breillat et al,1983
saline United state of pharmacopeia,1984
Ringer lactate United state of pharmacopeia,1984

Methylcellulose and Carboxymethylcellulose:
• Historically, methylcellulose was the vehicle of a paste widely used in South America, mainly in
Argentina.
• Maisto & Capurro introduced a paste composed of equal volumes of calcium hydroxide powder
and iodoform mixed with a 5% aqueous solution of methylcellulose.
• Its antibacterial effect was evaluated by Di Fiore et al, and it was recommended in Apexification
procedure and in indirect pulp capping.
Laurichesse proposed the following modification of the original formula:
• calcium hydroxide and iodoform in a ratio 2/3:1/3, two drops of camphorated parachlorophenol
and a 3% aqueous solution of methylcellulose as the vehicle.

• Giro et al. (1993) proposed the use of carboxymethylcellulose or, according to the United
States Pharmacopeia (1989), polycarboxymethylether of cellulose, as the vehicle in the
following formula:
0.5 g of calcium hydroxide to 0.5 mL of a 1.66% solution of carboxymethylcellulose
• In another suggested formulation, 0.25 g of zinc oxide was added for radiopacity.

Anionic detergent solution
• It is well known that detergents decrease the surface tension between two surfaces
and facilitate substance penetration.
• This is perhaps the reason why calcium hydroxide powder has been mixed with an
aqueous detergent solution to increase the action of the calcium hydroxide deeper
into the tissues.
Studies
• Barbosa et al. (1994) tested the antibacterial effect of a paste composed of calcium
hydroxide and sodium lauryl diethyleneglycol ether sulphate.
• Peniche et al. (1996) evaluated the pH of a paste containing calcium hydroxide and s
odium lauryl sulphate.

Proprietary Brands:
• Calxyl® (Otto & Co., Frankfurt, Germany).
• Pulpdent® and Tempcanal® (Pulpdent Corp., Brookline, MA, USA)
• TempCanal®
• Calvital® (Neo Dental Chemical Products Co., Tokyo, Japan)
• Reogan® (Vivadent, Schaan, Liechtenstein)
• Calasept® (Scania Dental AB, Knvista, Sweden):
• Hypocal® (Ellinan Co., Hewlatt, NY, USA)
• Calcicur® (VOCO, Auxhaven, Germany)
• DT Temporary dressing® (Dental Therapeutics AB, Nacka, Sweden)
• Calcipulpe®
• Hidropulpe® (Lab. Zizine, France).
• Serocalcium (Casa Wild, Basel, Switzerland).
• Hydroxine® (Lab. Ato Zizine, France).
• Acrical® (Bames-Hind Laboratories, USA).
• Calnex® (Associated Dental Products Ltd, London, UK).

Calxyl® (Otto & Co., Frankfurt, Germany)
• oldest manufactured→ and was introduced by Hermann (1920)
Uses
• As pulpotomy in vital pulp therapy
• As apical barrier formation in apexification
• Calxyl® Paste Syringe (pH> 12.6) is a Calcium hydroxide paste in a dosing syringe, unsurpassed for endodo
ntic treatment and temporary root filling.
• Calxyl® suspension is used for disinfection of the root canal
This paste is a solution of calcium hydroxide + water with the addition of th
e following blood salts: sodium carbonate, sodium chloride, calcium chlorid
e, potassium chloride and traces of magnesium.

Pulpdent® and Te
mpcanal®
of calcium hydroxide (52.5%) in an aqueou
s suspension of methylcellulose
DPC , pulpotomy,
apexification, perforations,
large periapical lesions and
external resorption.
Calvital® Powder+ liquid.
powder: calcium hydroxide (78.5%),
iodoform (20%), guanoflacin (0.1%) and
sulphatiazol (1.4%), liquid: T-cain (0.5%),
propyleneglycol (50%) and distilled water
(49.5%).
DPC, pulpotomy in deciduous
teeth, pulpotomy in permanen
t teeth, intracanal dressing afte
r vital pulpectomy and as a fin
al filling coupled with gutta-pe
rcha points
Reogan® calcium hydroxide, barium sulphate, casein
and magnesium hydroxide.
Apexification, dressing in vital
or non-vital teeth with or with
out periapical lesions radiogra
phically
Calasept® calcium hydroxide (56%), calcium chloride
(8 mg), sodium chloride (0.35 mg), sodium
bicarbonate (4 mg), potassium chloride (8
mg) and water sufficient for 100 g of the
paste.
IPC, DPC, apexification, in retre
atment cases and in luxated n
on-vital teeth43
Hypocal® calcium hydroxide (45%), barium sulphate (
5%), hydroxymethylcellulose (2%) and wate
r (48%). However, Ida et al.148 presented th
e following formula: calcium hydroxide (45
%), barium sulphate (5%), glycolcellulose (2
%) and distilled water (48%).
apexification
It Offers 3-Way Protection
Biological Protection: Desensitizes the
dentin by stimulating the formation of
sclerotic and reparative dentin and by
increasing the density of the dentin as
much as 25% in 15 days.
Chemical Protection: pH > 12. Neut
ralizes acids and other irritants foun
d in dental etching gels, adhesives a
nd restoratives.
Physical Protection: Fills the dentin
al tubules with calcium hydroxide.
Does not interfere with the seating
of crowns and inlays.

DT Temporary dressing® unoxygenated calcium hydroxide + sterilized distilled water
Calcipulpe® calcium hydroxide + carboxymethylcellulose
Hidropulpe® calcium hydroxide and barium sulphate in a solution of met
hyl benzoate
Calcigel® calcium hydroxide, methylcellulose and water
Acrical® 9-aminoacridine hydrochloride (0.2%), benzalkonium
chloride (0.1%), calcium hydroxide (28%) and barium
sulphate (5%). Benzalkonium chloride is a cationic detergent
and thus a watersoluble vehicle.
Calnex® sterilized calcium hydroxide plus blood serum salts and met
hylcellulose

• According to Silva the high molecular weight of these vehicles minimizes the dispersion
of calcium hydroxide into the tissue and maintains the paste in the desired area for
longer intervals.
• This factor prolongs the action of the paste, and Ca2+ and OH- ions will be given off at
lower velocity.
• It is through this mechanism that these pastes remain in direct contact with vital tissue
for extended time intervals.
• As a viscous vehicle containing paste may remain within the root canal for a 2-4 month
interval, the number of appointments and re-dressings of the root canal is drastically
reduced.
eg,
• glycerine,
• polyethyleneglycol
• propylene glycol.
Viscous vehicles

Glycerine
• Glycerine is a viscous, colourless transparent liquid with a characteristic odour, sweetish in
taste and hygroscopic.
• It can be mixed with water, acetone, alcohol and other glycols in any proportion but is
insoluble in chloroform, ether, benzene and volatile oils.
• Its molecular weight is 92.02

• Because of its hygroscopic properties, glycerine is very useful as a moistening substance
and, as it is soluble in water, it is easily removed.
• Furthermore, it is non-toxic and is used as an intracanal lubricant.
• The first use of a calcium hydroxide paste with glycerine in its formula was reported by
Steiner et al. in a paste composed of calcium hydroxide, camphorated parachlorophenol,
barium sulphate and glycerine.
• This paste was employed for root-end closure of immature non-vital teeth.
• The paste is obtained by mixing calcium hydroxide with synthetic glycerine and has
been evaluated for its antibacterial effect. A radiopacifier may be added to improve
radiopacity, such as iodoform or barium sulphate in a 1:8 ratio with the calcium
hydroxide powder.

This paste has been used in cases of
• chronic abcesses with extraoral fistulae (Salamat & Rezai 1986 CË aliskan et al. 1994)
• acute abcesses or chronic periapical lesions (CË aliskan & Sen 1996)
• internal resorption with or without root perforation (CË aliskan & Turkun 1997)
• repair a fractured root (CË aliskan & Pehlivan 1996)
• internal resorption (CË aliskan & Turkun 1996)

Polyethyleneglycol
• Polyethyleneglycol is a viscous, colourless liquid with a characteristic odour and it is
slightly hygroscopic.
• It is miscible in any proportion with water, acetone, alcohol and other glycols but is
insoluble in ether and benzene
• Its pH ranges between 4.5 and 7.5.
• A paste composed of calcium hydroxide (70%), iodoform (30%) and polyethyleneglycol
as the vehicle was employed by Bellacosa et al. in a clinical case of external/internal
resorption.

• Maeda (1960) → introduced a paste containing calcium hydroxide, polyethyleneglycol
1500 as a base and sulphisomidine and eugenol as antibacterial agents.
• Kurimoto (1961) → tested the same paste as an intracanal dressing, with and without the
antibacterial agents, in human infected pulpless teeth with associated periapical lesions an
d found a high frequency of favourable cases.
• Leonardo et al. → introduced a paste containing calcium hydroxide (2 g), polyethylenegly
col 400 (1.75 ml), barium sulphate (1 g) for radiopacity and hydrogenized colophony (0.05
g) to improve physical properties.
• Later Leonardo & Leal replaced the barium sulphate by zinc oxide in the same proportion.
Leonardo MR, Leal JM. Endodontic treatment root canals, 2nd Edn. Säo Paulo: Panamericana 1991.

Propyleneglycol.
• Propyleneglycol is a clear, colourless, odourless liquid with a slightly characteristic taste
resembling that of glycerine.
• Chemically, it is a dihydric alcohol with a syrup consistency, hygroscopic in nature
and non-toxic that can be mixed with water, acetone and alcohol in any proportion.
• It is widely employed as a useful vehicle for pharmaceutical preparations such as
antihistaminies, barbiturates, paracetamol and those used for parenteral administration
• Moreover, this substance is a suitable vehicle for members of the vitamin B group,
pyrazolines, aspirin and chloral hydrate

• Bhat & Walkevar demonstrated a strong antibacterial action of propyleneglycol against
common microorganisms found in infected root canals and suggested its wider
application in endodontics as a gentle vehicle for intracanal medicaments.
• Its hygroscopic nature permits the absorption of water, which ensures a good sustained
release of calcium hydroxide for long periods.
• Another advantage of this substance is its consistency, which improves the handling
qualities of the paste.
Bhat KS, Walkevar S. Evaluation of bactericidal property of propylene glycol for its possible use in endodontics. J Health Sci (Arogya) 1975;1:54-59.
The first report using a calcium hydroxide paste containing this vehicle
was by Saiijo (1957), who added antibacterial agents and asbestos powder

These pastes have been evaluated in humans,
• as an intracanal dressing after vital pulpectomy (Saiijo 1957, Machida 1960, Sekine
et al. 1963a)
• for the non-surgical treatment of large periapical lesions (Hussey & Kennedy 1990).

Calen® (S.S. White + Artigos D
entários, Rio de Janeiro, RJ, Bra
zil)
calcium hydroxide (2.5 g), zinc o
xide (0.5 g), hydrogenized colop
hony (0.05 g) and polyethylenegl
ycol 400 (1.75 ml).
✓ Apexification ,
✓ in the treatment of large peri
apical lesions originating fro
m infected root canals,
✓ as an interappointment dressi
ng in cases of vital pulpecto
my,
✓ in acute apical periodontitis
✓ in endodontic retreatment aft
er endodontic
✓ surgical failures
Calen + camphorated parachlor
ophenol® (S.S. White + Artigo
s Dentários, Rio de Janeiro, RJ,
Brasil).
Leonardo et al. added camphora
ted parachlorophenol (CMCP, 0.1
5 ml) to the original Calen formu
lation
non-vital and infected teeth with
associated periapical lesions.
Proprietary Brands

• Oily vehicles are non-water-soluble substances that promote the lowest solubility
and diffusion of the paste within the tissues.
• Pastes containing this kind of vehicle may remain within the root canal for longer
than the pastes containing aqueous or viscous vehicles.
Lopes HP. The use of calcium hydroxide associated with oily vehicle in endodontic treatment of teeth with necrosed pulp and open apex (
Thesis). Rio De Janeiro 1987.
Eg,
olive oil,
silicone oil,
camphor (the essential oil of camphorated parachlorophenol),
metacresylacetate
some fatty acids such as oleic, linoleic and isostearic acids
Oily vehicles

Olive oil
• Purified olive oil is a primrose or slightly green coloured liquid with a characteristic
odour, which is non-soluble in water but fairly soluble in alcohol.
• Chemically it is composed of esters of fatty acids such as oleic, linoleic, palmitoleic,
estearic and linolenic acids. It must be kept in an amber coloured flask.
• It promotes low solubility for the calcium hydroxide but improves its physical properties
• Because of the low solubility, the paste has a low diffusion within the tissues.

Camphorated parachlorophenol
• Camphorated parachlorophenol, or camphorated paramonochlorophenol (CMCP), was
introduced by Walkhoff in 1891..
• It comprises 33-37% parachlorophenol and 63-67% camphor.
• Parachlorophenol (C2H5OCl, molecular weight 128.56 has a characteristic phenolic
odour and is presented in crystal form.
• Camphor (C10H16O, molecular weight 152.54) is acetone obtained from Cinnamomum
camphora or synthetically in the laboratory; it has a characteristic and penetrating
odour, a bitter taste and low solubility in water..

• The pronounced disinfectant action of parachlorophenol depends on the liberation of
the chlorine in the presence of phenol.
• When camphorated parachlorophenol is the vehicle of a calcium hydroxide paste, it is
an oily vehicle because camphor is considered an essential oil with low solubility in
water.
• A paste containing the above constituents was introduced by Frank and Kaiser and
became very popular in the United States after the publication of an article describing
the guidelines for apexification procedures in human immature non-vital teeth.
Kaiser HJ. Management of the wide open apex with calcium hydroxide compounds. Twenty-First Annual Meeting Of The American Association Of En
dodontics. USA: Washington DC 1964.

Metacresylacetate.
• According to Weiss, this substance was first introduced to dentistry by Coolidge in 1912
for the treatment of necrotic pulps.
• Chemically, metacresylacetate is the acetic ester of metacresol in combination with
benzene.
• It is an oily liquid with antibacterial, analgesic and sedative properties.
• When calcium hydroxide is mixed with metacresylacetate, a chemical reaction occurs
yielding calcium cresilate and acetic acid.
• The acetic acid suffers an ionic dissociation and gives off H+ ions, which decreases the pH

Eugenol
• Molecular weight 164.20
• Obtained from oil of cloves and other sources (United States Pharmacopeia 1989).
• A paste containing calcium hydroxide and eugenol was evaluated for pulpotomy in deciduous
dog teeth (Russo & Holland 1974).
• In humans it has been employed as an intracanal dressing for vital and non-vital deciduous
teeth (Murata 1959).

Proprietary Brands
L & C® (Herpo Produtos DentArios Ltda., Rio d
e Janeiro, RJ, Brazil).
✓ introduced by Lopes & Costa Filho
✓ powder : calcium hydroxide (2 g), bismuth
carbonate (1 g) and hydrogenized colophony
(0.05 g),
✓ liquid: olive oil (0.16 ml).
use→ Apexification, resorptions and perforations
Vitapex® (Neo Dental Chemical Products Co. L
td, Tokyo, Japan).
✓ introduced by Kawakami et al
✓ calcium hydroxide (30.3%), iodoform (40.4%),
silicone oil (22.4%) and other substances
(6.9%).
Use – as root canal filling material in primary
teeth

Calcium Hydroxide and Other Substances
Radiographic Contrast Media
• Calcium hydroxide mixed with any of the quoted vehicles lacks radiopacity and is not easily
seen radiographically.
• This is the main reason radiopaque materials are added to the paste, thereby allowing
identification of lateral and accessory canals, resorptive defects, fractures and other structures.
• A radiopacifier should have an atomic weight higher than calcium for radiopacity purposes.
• Eg, barium sulphate and bismuth, and other compounds containing iodine and bromine.
• As bismuth salts have some degree of toxicity and soluble barium salts are extremely toxic
materials and relatively insoluble, the actual alternative is to use a more soluble radiopaque
substance.

• Tavano et al.1978, stated that there are three types of iodine compounds:
soluble iodine organic substances,
nonsoluble iodine oils
slowly absorbable iodine oils.
• When mixed with calcium hydroxide powder, these substances will become the
vehicle of the paste as well as being the radiopaque agent.

Corticosteroid-Antibiotic Solutions
• The use of corticosteroids to reduce inflammation and maintain the vitality and integrity
of the injured pulp tissue is an established procedure.
• As calcium hydroxide has been proved to offer better clinical results, some attempts have
been made to mix these two substances and evaluate these formulations for endodontic
purposes in vital pulp therapy, such as in direct pulp capping and pulpotomy procedures.
Fiore-Donno G. Baume LJ. Effects of capping compounds containing corticosteroids on the human dental pulp.
Helvetia Odontologicacta 1962;6:23-32.

• A very popular formulation is a paste composed of a mixture of calcium hydroxide and
Ledermix (Lederle Lab.).
• This anti-inflammatory + antibiotic compound has triamcinolone acetonide and
demethylchlorotetracycline calcium and clinically evaluated in direct pulp capping,
pulpotomy, routine intracanal dressing and apexification procedures and in the treatment of
large periapical lesions.

Antibiotics
• Quillin et al. suggested adding metronidazole and chlorhexidine to a calcium
hydroxide paste and tested this formulation for its antibacterial effect.
• Another association was proposed by Antoniazzi & Marques, which involved mix
ing calcium hydroxide (0.13 g), metronidazole (0.6 g), ciprofloxacin (0.6g) and
polyethyleneglycol 1000.

Calcium Hydroxide's Association With Different Vehicles: In Vitro Action on
Some Dentinal Components
(María Gabriela Pacios,2003)
[chlorhexidine digluconate, propylene glycol (PG), anesthetic solution, camphora
ted monochlorophenol (CMCP), and CMCP-PG. The control solution contained
Ca(OH)(2) without vehicle.]
conclusion - test solutions with the root dentin remained alkaline. A release of
proteins, hydroxyproline, and phosphorus was observed.
Influence of Different Vehicles on the pH of Calcium Hydroxide Pastes
(María Gabriela Pacios,2004)
distilled water, chlorhexidine, propylene glycol, anesthetic solution, camphorated
p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol.
Conclusion - The type of vehicle was shown to influence the final pH of the pas
tes.
Efﬁcacy of calcium hydroxide paste prepared
with different vehicles against salivary
microbial inﬁltration of root canals.
(Marili D, 2013)
saline solution (Group 1), polyethylene glycol (Group 2),
or polyethylene glycol and camphorated paramonochlorophenol (Group 3).
Conclusion - Calcium hydroxide paste prepared with saline solution was most
effective for retarding microbial contamination
Effect of calcium hydroxide pastes and vehicles on root canal dentin microh
ardness
(María G Pacios,2014)
The vehicles are: Distilled water, chlorhexidine, carticaine in the anesthetic soluti
on, propylene glycol, monochlorophenol and monochlorophenol - propylene gl
ycol.
Conclusion - All vehicles and pastes, except distilled water, significantly decrease
d the microhardness of the root dentin; however, calcium hydroxide + camphor
ated monochlorophenol - propylene glycol and camphorated monochlorophen
ol - propylene glycol showed the highest decrease

Evaluation of calcium ion release and change in pH on combinin
g calcium hydroxide with different vehicles
(C Grover, 2014)
-distilled water, propylene glycol, gutta-percha points and chitosan
Conclusion - Chitosan can be used as a promising vehicle for calcium
hydroxide to maintain an alkaline pH and to allow sustained release
of calcium ions in the root canal system.

Antimicrobial properties of calcium hydroxide dressing when used for long-term application: A systematic review
(Garima Sharma,2018)

BASED ON MATERIALADDED
• Calcium hydroxide compounds are often classified as → homogeneous group of materials,
generally in terms of a list of trade names; however, because of the differing chemical
composition of such compounds, it seems advisable to differentiate various subgroups.

Based on Material Added to Calcium Hydroxide
Subgroup Hardening reaction
Trade name/ example
1
Aqueous suspension (water
+ calcium hydroxide)
Generally lacking (formation of salts
at the surface)
Pulpdent ® paste
2
Liner
(varnish + calcium hydroxid
e)
Evaporation of the solvent Hydroxyline®
3
Paste
(oil + calcium hydroxide)
Saponification Gangraena®
Merz ®
4
Cement
(acid + calcium hydroxide)
Formation of salts/chelates Dycal ®
5
Filled resin (polymerizing w
ith calcium hydroxide)
Polymerization
Prisma ®
VLC – Dycal ®

Advantages of Calcium hydroxide
✓ Initially bactericidal then bacteriostatic.
✓ Promotes healing and repair.
✓ High pH stimulates fibroblasts.
✓ Neutralizes low pH of acids.
✓ Stops internal resorption.
✓ Inexpensive and easy to use.

Disadvantage
✓ Does not exclusively stimulate dentinogenesis.
✓ Does not exclusively stimulate reparative dentin.
✓ Associated with primary tooth resorption.
✓ May dissolve after one year with cavosurface dissolution.
✓ May degrade during acid etching.
✓ Degrades upon tooth flexure.
✓ Marginal failure with amalgam condensation.
✓ Does not adhere to dentin or resin restoration

Mechanism of action
• calcium hydroxide has been recommended for use in several clinical situations.
• Depending on its application, the mode of action of Ca(OH)2 may vary.
(A)Antimicrobial activity
(B)Mineralization activity
(C)Effect of liquid vehicle
(D) As a physical barrier
• Antibacterial activity
• Effects on endotoxins
• Antifungal activity
• Buffering effect of dentine on the antibacterial
activity of ca(oh)2
• Combination of ca(oh)2 and chlorhexidine

TRONSTAD ET AL (1981):
• Raise in ph
TORNECK ET AL (1983):
High ph activate alkaline phosphatase activity

ANTIBECTERIAL ACTIVITY
• Most of the endodontopathogens are unable to survive in the highly alkaline environment provided by
calcium hydroxide.
• Since the pH of calcium hydroxide → 12.5, several bacterial species commonly found in infected root
canals are eliminated after a short period when in direct contact with this substance.
• Antimicrobial activity of calcium hydroxide is related to the release of hydroxyl ions in an
aqueous environment.
• Hydroxyl ions are highly oxidant free radicals that show extreme reactivity, reacting with several
biomolecules.
Siqueira Jr JF, Lopes HP. Mechanisms of antimicrobial activity of calcium hydroxide: a critical review (
Review). International Endodontic Journal, 32, 361±369, 1999

➢ Their lethal effects on bacterial cells are probably due to the following mechanisms:
1. Damage to the bacterial cytoplasmic membrane
2. Protein denaturation
3. Damage to the DNA

(1) Damage to the bacterial cytoplasmic membrane
The bacterial cytoplasmic membrane is responsible for essential functions such as,
❖ metabolism,
❖ cellular division and growth; and it takes part in the final stages of cellular wall formation,
❖ biosynthesis of lipids,
❖ transport of electrons
❖ oxidative phosphorylation.

These functions taken into action by,
(i) Selective permeability and transport of solutes;
(ii) Electron transport and oxidative phosphorylation in aerobic species
(iii)Excretion of hydrolytic exoenzymes
(iv)Bearing enzymes and carrier molecules that function in the biosynthesis of DNA, cell wall polymers,
and membrane lipids
(v) Bearing the receptors and other proteins of the chemotactic and other sensory transduction systems.
Brooks GF, Butel JS, Morse SA. Jawetz, Melnick, And Adelberg's Medical Microbiology, 21st Edn 1998.Stamford,
Ct: Appleton & Lange.

• Thus, peroxides themselves act as free radicals, initiating an autocatalytic chain reaction,
and resulting in further loss of unsaturated fatty acids and extensive membrane damage,
which is a saponification reaction.
Hydroxyl ions induce
lipid peroxidation,
resulting in the
destruction of
phospholipids,
Hydroxyl ions remove
hydrogen atoms from
unsaturated fatty acids,
generating a free
lipidic radical.
This free lipidic radical
reacts with oxygen,
resulting in the
formation of a lipidic
peroxide radical, which
removes another
hydrogen atom from a
second fatty acid,
generating another
lipidic peroxide.
Z Mohammadi, Antimicrobial Activity of Calcium Hydroxide in Endodontics: A Review; Chonnam Med
J 2012;48:133-140

(2) Protein denaturation
• Cellular metabolism is highly dependent on enzymatic activities.
• Extracellular enzymes act on nutrients, carbohydrates, proteins and lipids that, through
hydrolysis, favour digestion.
• Intracellular enzymes located in the cell favour respiratory activity of the cellular wall structure.
• Enzymes have optimum activity and stability in a narrow range of pH, which turns around
neutrality.

• The alkalinization provided by calcium hydroxide induces the breakdown of ionic bonds that maintain
the tertiary structure of proteins.
• As a consequence, the enzyme maintains its covalent structure but the polypeptide chain is randomly
unravelled in variable and irregular spatial conformation.
• These changes frequently result in the loss of biological activity of the enzyme and disruption of the
cellular metabolism.
• Structural proteins may also be damaged by hydroxyl ions.
Siqueira Jr JF, Lopes HP. Mechanisms of antimicrobial activity of calcium hydroxide: a critical review (
Review). International Endodontic Journal, 32, 361±369, 1999

(3) Damage to the DNA
• Hydroxyl ions react with the bacterial DNA and induce the splitting of the strands.
• Genes are then lost. Consequently, DNA replication is inhibited and the cellular activity is disarranged.
• Free radicals may also induce lethal mutations.
• Scientific evidence suggests that the three mechanisms may occur. Thus, it is difficult to establish, in
a chronological sense, which is the main mechanism involved in the death of bacterial cells after
exposure to a strong base.

Adjustment of intracellular pH is influenced by several cellular processes such as the following:
❖ Cellular metabolism
❖ Alterations in shape, mobility, adjustment of transporters and polymerization of cytoskeleton components
❖ Activation of cellular proliferation and growth
❖ Conductivity and transport through the membrane
❖ Isosmotic cellular volume
• Thus, many cellular functions can be affected by pH, including the enzymes that are essential for cellular
metabolism.

• It has been suggested that the ability of calcium hydroxide to absorb carbon dioxide may contribute to it
s antibacterial activity.
• However, cementum is permeable to water, ions and small molecules.. Hence, CO2 supply to remaining
bacteria in the root canal system may be maintained from the outside.
• In addition, bacteria located in ramifications have direct access to carbon dioxide from the periradicular
tissues.
• There is little reason to consider that calcium hydroxide impedes the carbon dioxide supply to bacteria.
J 2012;48:133-140

EFFECTS ON ENDOTOXIN endotoxins do not cause cell or tissue
pathosis directly but instead stimulate
competent cells to release chemical
mediators
Macrophages are the main
target of endotoxins
J 2012;48:133-140

During root canal treatment
LPS is released during multiplication or bacterial death, thus causing a series
of biological effects that lead to an inflammatory reaction and periapical bone
resorption.
In teeth with chronic periapical lesions, there is a greater prevalence of
Gram-ve anaerobic bacteria disseminated throughout the root canal system
(dentinal tubules, apical resorptive defects, and cementum lacunae), including
apical bacterial biofilm.

Because these areas are not reached by instrumentation, the use of a root canal medicament is
recommended to aid in the elimination of these bacteria and to increase the possibility of clinical
success
The procedures and medicaments used in root canal treatment
should lead not only to bacterial death but also to the inactivation
of bacterial endotoxin

Anti-endotoxin studies of ca(OH)2

ANTI-FUNGAL ACTIVITY
✓ Fungi have occasionally been found in primary root canal infections,
but they appear to occur more often in filled root canals of teeth in
which treatment has failed.
✓ Candida glabrata, C. guilliermondii, C. parapsilosis, C. krusei,
C. inconspicua, C. dubliniensis, C. tropicalis, and
Saccharomyces species.
✓ C. albicans fungal species most commonly isolated from infected root
canals.
J 2012;48:133-140

✓ It seems that the combinations of Ca(OH)2 with camphorated paramonochlorophenol or
chlorhexidine have the potential to be used as effective intracanal medicaments for cases
in which fungal infection is suspected.
J 2012;48:133-140

➢ Siqueira et al. investigated the antifungal ability of several medicaments against C. albicans, C. glabrata,
C. guilliermondii, C. parapsilosis, and Saccharomyces cerevisiae.
➢ They reported → the paste of Ca(OH)2 in camphorated paramonochlorophenol (CMCP)/glycerin had the
most pronounced antifungal effects.
J 2012;48:133-140

➢ Valera et al. showed that, as an intra-canal medicament, CMCP was more effective against C.
albicans than Ca(OH)2 /CMCP paste.
Z Mohammadi, Antimicrobial Activity of Calcium Hydroxide in Endodontics: A Review; Chonnam Med J 2012;48:133-140

BUFFERING EFFECT OF DENTINE ON THE ANTIBACTERIAL ACTIVITY OF Ca(OH)2
❖ The root canal milieu is a complex mixture of a variety of
organic
inorganic
Hydroxyapatite
pulp tissue,
microorganisms,
inflammatory exudate
albumin
J 2012;48:133-140

• Haapasalo et al. introduced a new dentine powder model for studying the inhibitory effect
of dentine on various root canal irrigants and medicaments.
Conclusion
• dentine powder effectively abolished the killing of E. faecalis by Ca(OH)2 .
• Hydroxyapatite had an effect similar to dentine on Ca(OH)2 , preventing the killing of E. faecalis.
❖ The substantial effect of dentine on the antibacterial activity of Ca(OH)2 can be attributed to the buffering
action of dentine against alkali.

• Both laboratory and in vivo studies have shown that buffering by dentine, particularly in the subsurface
layers of the root canal walls, might be the main factor behind the reduced antibacterial effect of Ca(OH)2
• It is possible that deeper in dentine (outside the main root canal), Ca(OH)2 is present as a saturated
solution or at concentrations even below that level.
• Besides dentine, remnants of necrotic pulp tissue as well as inflammatory exudate might affect the
antibacterial potential of endodontic disinfectants.

COMBINATION OF Ca(OH)2 AND CHLORHEXIDINE
• Chlorhexidine (CHX) is a cationic biguanide whose optimal antimicrobial activity is achieved with
in a pH range of 5.5 to 7.0
• Therefore, it is likely that alkalinizing the pH by adding Ca(OH)2 to CHX will lead to precipitation
of CHX molecules, thereby decreasing its effectiveness.
• When used as an intracanal medicament, CHX was more effective than Ca(OH)2 in eliminating
E. faecalis from inside dentinal tubules.
• Haenni et al. found no additive antibacterial effect by mixing Ca(OH)2 powder with 0.5% CHX.
They indicated that CHX had a reduced antibacterial action.
J 2012;48:133-140

Ballal et al. (2007) found that 2% CHX gel was a more effective medicament than Ca(OH)2 past
e against E. faecalis.
Krithikadatta et al. (2007) reported that, as an intracanal medicament, 2% CHX gel alone was
more effective against E. faecalis when compared to Ca(OH)2.

THEORIES OF MINERALIZATION
The three theories are
• Alkaline phosphatase theory or booster theory
• Seedling theory or nucleation theory or collagen template theory
• Matrix vesicle theory

Alkaline Phosphatase theory or booster theory
✓ It was introduced by Robinson in 1923.
✓ It is also known as booster theory.
✓ Here a booster mechanism such as an enzyme activity acts by raising the concentration of calcium
phosphate ions leading to precipitation.
✓ It is considered that the soft tissue contains inhibitors of mineralization.
✓ In order to initiate nucleation these same inhibitors have to be inhibited at the site of hard tissue
formation.

Once the nuclei are established, the level of
super saturation of the interstitial fluids is high
enough for the growth of hydroxyapatite crystal.
The energy needed for the nucleation is met by
elevating the local ionic concentration of
calcium ions and phosphate ions.
This is brought about by an enzyme known as
alkaline phosphatase. Hence this theory is
also known as alkaline phosphatase theory. This
process brings about homogenous
mineralization.
✓ The energy required for
the formation of crystal
nuclei is higher than that
needed for continued
crystal growth.

OBJECTIONS
✓ Based on an experimental study conducted on a diseased tissue.
✓ Alkaline phosphatases seen in other tissues which do not calcify
✓ Organic phosphate not sufficient to produce inorganic phosphate to initiate
calcification process.

MATRIX VESICAL THEORY
✓ Discovered by Anderson &Ermanno Bonucci
✓ Matrix vesicals are organelles of cellular origin that can be observed electron microscopically
in the matrix of cartilage, bone,&other hard tissues
✓ MVT states that ,due to presence of vesicles containing apatite crystals near each cartilage
cell which aggregate & form a matrix which is mineralised.

Mineralization within mesenchymal tissues
Initiation of mineralization Calcium hydroxide induced mineralization
(B) MINERALIZATION ACTIVITY

It is now widely accepted that an epitactic mechanism operates following the initial seeding of a collagenous
tissue.
• Only certain types of collagen, such as those found in dentine and bone, mineralize in this way.
• The process is probably the result of the juxtaposition of charged groups on adjacent macromolecules
which give rise to the epitactic centres.
• These centres require a nucleation site from which hydroxyapatite crystal growth can proceed.
• Numerous theories abound as to the initiator of the process.
Initiation of mineralization

• Some workers have implicated chondroitin sulphate as the seed whilst others, conversely, considered it
to be an inhibitor of mineralization.
• Other substances which have been postulated as initiators of mineralization include a vitamin D
dependent protein which is capable of binding calcium, phosphoproteins and phospholipids.
Irving J.T. Epitaxy Down The Ages.1981. In the chemistry and biology of .mineralised connective tissue, Elsevier
253-255.

• Of equal importance to the induction of mineralization is the ability to halt the process.
• One safety factor may be the presence in the blood and tissue of substances such as pyrophosphate i
ons which act as inhibitors.
• This action is lost when pyrophosphates are metabolized at the mineralization sites by pyrophosphata
se.
• Pyrophosphatase is a member of the alkaline phosphatise group, which may explain why these enzyme
s are invariably present in mineralizing tissues.
Irving JT, Wuthier RE. Histochemistry and biochemistry of calcification with special reference to the role of lipids.
Clinic Orthopaed Rel Res 1968;56:237-260

Calcium hydroxide induced mineralization

Histological perspective
Holland R. Histochemical Response of amputed pulps to calcium hydroxide. Review Of BrasıLia Pesqui Med E Bi
o 1971;4:83–95.
(a) Zone of Obliteration
(b) Zone of Coagulation Necrosis
(c) Line of Demarcation
(d) Early stage of Dentin Bridge Formation
(e) Calcification of the Bridge

(a) Zone of Obliteration
• The pulp tissue immediately in contact with calcium hydroxide is usually completely deranged
and distorted because of the caustic effect of the drug.
• This zone consist of debris, dentinal fragments, haemorrhage, blood clot, blood pigments, and
particles of calcium hydroxide.
• This zone of obliteration is due to → the chemical injury as a result of high concentration of
hydroxyl ions and due to the high pressure of the medicament application. (Schoder and
Granath 1971)

(B) Zone of Coagulation Necrosis
• The tissue together with its plasma proteins within the zone of obliteration takes the
brunt of the calcium hydroxide chemical thrust.
• A weaker chemical effect reaches the subjacent, more apical tissues and results in a zone of
coagulation necrosis and thrombosis, also called Schroder’s layer of “firm necrosis” and
Stanley’s “mummified zone”.
• This zone is 0.3 – 0.7 mm thick and represents devitalized tissue without complete
obliteration of structural architecture.
• Outline of capillaries, nerve bundles and pyknotic nuclei can still be recognized.

(C) Line of Demarcation
• Between the deepest zone of coagulation necrosis and the subjacent vital pulp tissue the line of
demarcation develops
• This line resulted from the reaction of CH with tissue protein to form proteinate globules
• The migration of inflammatory cells begin as early as 6hrs after injury.

(D ) A Danse Zone (Early Stage Of Dentin Bridge Formation)
✓ Immediately subjacent to the line of demarcation proliferation of mesenchymal cells occur
✓ Within 2-3 days after the injury, connective tissue fibres accumalate
✓ At first they are disorganised, consisting of both fine and coarse fibres lying parallel to the applied
medicament
✓ The increase in collagen formation becomes apparent at 3- 7 days

✓ The number of fibroblast, mesenchymal cells multiply sufficiently to present a modified cell rich layer
✓ The cells within this layer gradually differentiate into pre-odontoblast and columnar shaped odonto
blasts.
✓ By 7 days the matrix thickens and becomes more differentiated.
✓ The replication of odontoblasts favored over fibroblast because of basic environment.

The Dentine Bridge
• A mineralized barrier or 'dentine bridge' is usually produced following the application of calcium hydr
oxide to a vital pulp.
• This repair material appears to be the product of odontoblasts and connective tissue cells.
Histological Section - Arrow Shows Dentin Bridge Formation by Calcium Hydroxide

• Calcium ions release from calcium hydroxide stimulates fibronectin synthesis in dental
pulp cells.
• Fibronectin might induce the differentiation of dental pulp cells to mineralized tissue
forming cells that are the main cells to form dentine bridges, via direct contact.
Histological Section Showing Hard Tissue Formation Followed by 90 Days of Calcium Hydrox
ide Application

After 24 hrs
After 4-5 weeks
After 2-3 weeks
After 8 weeks

CALICIFICATION OF THE BRIDGE
A mineralized barrier or dentin bridge is usually produced following the application of Ca(OH)2.
Necrotic zone is formed adjacent to the material and the dentin bridge is formed between this
necrotic layer and underlying vital pulp .
Calcification occurs soon after the predentin has developed.
The stage of tubular predentin formation may be reached in 2 weeks
After 1-3 month the barrier consists of more coronal layer of irregular osteodentin like tissue with
cellular inclusions and the pulpal part consists of predentin lined with odontoblasts.

With this high Ph CH, bridge formation occurs at the line of demarcation
Over a period of time the coaguated necrotic tissue above the line of demarcation degenerates
In case of lower PH such as dycal the necrotic zone similarly formed, but is resorbed prior to the dentin
bridge which then forms to be directly against the capping material.
Dentinal bridge formed by high PH materials are histologically similar to those produced by lower PH materia
l but are easier to distinguish on a radiograph because of the space B/W the bridge and Ca(OH)2

❖ Acc to Cox et al. 89 % of all dentin bridges contain multiple tunnel defects.
❖ These multiple tunnel defects present a morphological distruption of the dentin bridge barrier in that they
not only fail to provide a permanent barrier, but they also fail to provide a long term biological seal again
st bacterial infection.
❖ Tunnel defects in dentinal bridge – allow the leakage of bacteria into pulp tissue and are a measure of
quality or sealing of the dentinal bridge. (peter murray AJD 2006)

AS A PHYSICAL BARRIER
• In addition to eliminating remaining viable bacteria unaffected by the chemomechanical preparation of
the root canal, intracanal medicaments have been advocated for other reasons.
• They should also act as a physicochemical barrier, precluding the proliferation of residual microorganis
ms and preventing the re-infection of the root canal by bacteria from the oral cavity.

Intracanal medicaments may prevent the penetration of bacteria from saliva in the root canal
basically in two ways
First, medicaments possessing antibacterial properties may act
as a chemical barrier against leakage by killing bacteria, thereby
preventing their ingress into the root canal.
Secondly, medicaments that fill the entire length of the root canal
act as a physical barrier against bacterial penetration.

✓ Under ideal conditions, residual pulp tissue and the odontoblastic layer may form a matrix, such that the
subsequent calcification can be guided by the reactivated epithelial cell rests of Malassez or non periapical
pluripotent cells within bone.
✓ Barrier formation also depends on the degree of inflammation and pulp necrosis, displacement at the time of
trauma, and number of calcium hydroxide dressings, which can complicate (or at least delay) treatment.

Under ideal conditions, residual pulp tissue and the odontoblastic layer may form a matrix, such that the subsequent calcification ca
n be guided by the reactivated epithelial cell rests of Malassez or non periapical pluripotent cells within bone.
Barrier formation also depends on the degree of inflammation and pulp necrosis, displacement at the time of trauma, and number of
calcium hydroxide dressings, which can complicate (or at least delay) treatment.
high pH, the highly reactive hydroxyl ions produce damage to the bacterial cytoplasmic membrane by denaturing protein and
destroying lipoproteins, phospholipids, and unsaturated fatty acids.
Consequently, these actions lead to bacterial vulnerability and alteration of the nutrient transport and DNA.
An alkaline environment neutralizes lactic acid from osteoclasts, avoiding dissolution of the dentin mineral components.
Calcium ions can induce expressions of type I collagen, osteopontin, osteocalcin, and alkaline phosphatase enzyme in osteoblasts a
nd mineralization through the phosphorylation of p38 mitogen-activated protein kinase and cJun N-terminal kinase
Alkaline phosphatase liberates inorganic phosphatase from phosphate esters.
It can separate phosphoric esters, releasing phosphate ions that react with bloodstream calcium ions to form calcium phosphate
of hydroxyapatite.

Bone morphogenetic protein-(BMP-)2is a growth factor that is expressed in presence of calcium hydroxide.
BMP-2 aids the regeneration of bone, cementum, and periodontal tissue.
Additionally, BMP-2 may bind to extracellular matrix type Iv collagen
Barrier formation

p38 mitogen-activated
protein kinase and cJun
N-terminal kinase
Barrier formation

Clinical applications of calcium hydroxide

1) CALCIUM HYDROXIDE AS A CAVITY LINER
✓ The calcium hydroxide pastes are now in general use as lining materials.
✓ Their perceived advantages, in addition to their therapeutic effects are as follows:
• They have a rapid initial set in the cavity under the accelerating effect of moisture.
• They do not interfere with the setting reaction of the Bis-GMA resins.
• 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 the lathe cut amalgam all
oys

• Liners are relatively thin layers of material used primarily to provide a barrier to protect
the dentin from residual reactants diffusing out of a restoration.
• Liners are of two types
1. Thin film liners
2. Thick liners
Thin liners (1-50µm)
1. Solution liner or varnishes (2-5µm)
2. Suspension liners (20-25µm)
Thick liners
• Also called cement liners (0.2-1mm).
Used primarily for pulpal medications and thermal protection
• bases (1-2mm) provide thermal protection and mechanical support for the restoration by
distributing local stresses from the restoration across the underlying dentin surface

AS A BASE AND A SUB BASE
• Calcium hydroxide can be used both as a sub base and as a base.
• It should be placed deep in deep portions of the cavity preparation subs
equently covered by a definitive supporting base.
• It helps in repair of pulpal tissue
• It provides chemical insulation
• It replaces the lost portion of the dentin.
• Calcium hydroxide bases are of relatively of low strength when compared to th
e other bases. These bases are used only for their therapeutic benefits, chemical
insulation or for retaining the sub bases.

INDIRECT PULP TREATMENT
Carious dentin actually consists of two layers having different ultramicroscopic and chemical structures.
The outer carious layer is irreversibly denatured, infected and incapable of being remineralized and hen
ce should be removed.
The inner carious layer is reversibly denatured but not infected and is capable of being remineralized
The technique

Response to the treatment:
Three distinct types of new dentin in response to indirect pulp treatment are seen:
• Cellular fibrillar dentin at two months post treatment
• Presence of globular dentin during the first three months
• Tubular dentin in amore uniformly mineralized pattern.

The histological evaluation:
The pulp reactions to the indirect pulp treatment are as follows:
Four layers have been demonstrated
1. Carious decalcified dentin
2. Rhythmic layers of irregular reparative dentin
3. Regular tubular dentin
4. Normal pulp with a slight increase in the fibrous elements.

Indirect pulp treatment: in vivo outcomes of an adhesive resin system
vs calcium hydroxide for protection of the dentin-pulp complex
(Falster et al.,2002)
protection of the dentin-pulp complex of primary molars with an
adhesive resin system results in similar clinical and radiographic 2-ye
ar outcomes as compared to calcium hydroxide when indirect pulp
treatment is performed in Class I composite restorations
Evaluation of indirect pulp capping using three different materials: A
randomized control trial using cone-beam computed tomography
(Mathur, et al.,2017)
Similar significant findings were obtained in radiodensity of barrier
formed (in HU). All three materials were found to be equally suitable
as IPC agents suggesting mineral gain
Clinical and radiographic evaluation of indirect pulp treatment of you
ng permanent molars using photo-activated oral disinfection versus ca
lcium hydroxide: a randomized controlled pilot trial
(Marwa Aly Elchaghaby,2020)
The success for both groups was 100% clinically and radiographically
at all follow-up periods.
there was no statistically significant difference between both groups at
2, 6, 9, and 12 months
Supportive studies

Contradict meta-analysis
Is a calcium hydroxide liner necessary in the treatment of deep caries lesions? A systematic
review and meta-analysis
(da Rosa et al. Calcium hydroxide liner in deep caries lesions – a meta-analysis
International Endodontic Journal, 52, 588–603, 2019)

Conclusion
✓ Although CH liner is commonly used by clinicians in deep carious lesion treatments, the availa
ble literature demonstrated that this material has no beneficial influence on the clinical success
of selective or stepwise removal of carious tissue.
✓ For primary teeth, the level of evidence was moderate when CH liner was compared with GIC,
and low when it was compared with inert materials or adhesive systems.
✓ For permanent teeth, evidence of very low quality indicated that CH liner would have no effect
on clinical success of deep caries lesion treatments.

Direct pulp capping treatment
• Calcium hydroxide is generally accepted as the material of choice for pulp capping.
• Histologically there is a complete dentinal bridging with healthy radicular pulp under calcium hydroxide
dressings.
• When calcium hydroxide is applied directly to pulp tissue there is necrosis of adjacent pulp tissue and an
inflammation of contiguous tissue.

• Dentinal bridge formation occurs at the junction of necrotic tissue and vital inflamed tissue.
• Beneath the region of necrosis → cells of underlying pulp tissue differentiate into odontoblasts
and elaborate dentin matrix.
• Three main calcium hydroxide products are: Pulpadent, Dycal, Hydrex(MPC).
Pulpadent paste is considered to be most capable of stimulating early bridge formation.
Hydrex has been considered that fast capable of forming a bridge
• Commercially available compounds of calcium hydroxide in a modified form are known to be
less alkanine and thus less caustic on the pulp.

Mineral Trioxide Aggregate (MTA) vs Calcium
Hydroxide in Direct Pulp Capping – Literature Review
Nawras Maher Mostafa, Shady Ahmed Moussa. Mineral Trioxide Aggregate (MTA) vs Calcium Hydroxide in Direct
Pulp Capping – Literature Review. On J Dent & Oral Health. 1(2): 2018. OJDOH.MS.ID.000508
Review – calcium hydroxide
- MTA
- `biodentin
- adhesive system
- zoe
-GIC/ RMGIC
Conclusion → MTA is more predictable than dycal in formation
of dentin barrier and superior in dentinogenesis process

Different materials for direct pulp capping: systematic review and
meta-analysis and trial sequential analysis
Falk Schwendicke, Clin Oral
Invest, April-2016
Conclusion → To
reduce risk of failur
e, dentists might
consider using
MTA instead of
calcium hydroxide
(CH) for direct cap
ping.

CALCIUM HYDROXIDE IN PULPOTOMY
• It is the most recommended pulpotomy medicament for pulpally involved vital young permanent tooth
with incomplete apices.
• It is acceptable because it promoted reparative dentin bridge formation and thus radicular pulp vitality
is maintained to allow uninterrupted physiological completion of root and root canals
Calcium hydroxide
Zoe

• Histologically pulp tissue adjacent to calcium hydroxide was first necrotized →high pH
of calcium hydroxide.
• This necrosis was accompanied by the acute inflammatory changes in the underlying tissue.
• After 4 weeks a new odontoblastic layer and eventually a bridge of dentin developed.

Three histologic zones under calcium hydroxide in 4-9 days:
1. Coagulation necrosis.
2. Deep staining areas with varied osteodentin.
3. Relatively normal pulp tissue, slightly hyperemic, underlying an odontoblastic layer.

Internal resorption may result from overstimulation of the primary pulp by the highly
alkaline calcium hydroxide.
• This alkaline induced overstimulation could cause metaplasia within the pulp tissue,
leading to formation of odontoclasts.
• Also undetected microleakage could allow large numbers of bacteria to overwhelm the
pulp and nullify the beneficial effects of calcium hydroxide
• At present calcium hydroxide pulpotomy technique cannot be generally recommended for primary teeth.
• recommended agent for carious and traumatic exposures in young permanent teeth, particularly with
incomplete closure.

Evaluation of formocresol, calcium hydroxide, ferric sulfate, an
d MTA primary molar pulpotomies
(Esma Yildiz,2014)
FC: formocresol, FS: ferric sulfate, CH: calcium hydroxide, an
d MTA: mineral trioxide aggregate)
→At 30 months, clinical success rates were 100%, 95.2%, 96.4
%, and 85% in the FC, FS, MTA, and CH groups, respectively.
Clinical and radiographic evaluation of biodentine versus calci
um hydroxide in primary teeth pulpotomies: a retrospective stu
dy
(Silvia Caruso1,2018)
Biodentine exhibited a higher clinical and radiographic success
rate compared to CH. However, besides the clinical results, bio
dentine has some disadvantages, such as higher costs,
compared to CH.

Calcium hydroxide as a root canal filling material for primary teeth in pulpectomy
A comparison of calcium hydroxide/iodoform paste and zinc oxide eugenol as root filling materials
for pulpectomy in primary teeth: A systematic review and meta‐analysis
(NAJJAR ET AL. Clin Exp Dent Res. 2019;5:294–310)

Conclusion → due to its resorbable property, Ca(OH)2/iodoform is the best filling material to
be used for pulpectomy in primary teeth nearing exfoliation.
Conversely, either ZOE or ZOE/iodoform combined with Ca(OH)2 is the materials of choice for
pulpectomy in primary teeth need long time before exfoliation

CALCIUM HYDROXIDE IN WEEPING CANALS
• Sometimes a tooth undergoing root canal treatment shows constant clear or reddish exudate associated
with periapical radiolucency.
• Tooth can be asymptomatic or tender on percussion.
When opened in next appointment, exudates stops but it again reappear in next appointment, this is
known as “weeping canal”.
• For such teeth dry the canals with sterile absorbent paper points and place calcium hydroxide in canal.
• It happens because pH of periapical tissues is acidic in weeping stage which gets converted into basic
pH by calcium hydroxide.

• Calcium hydroxide can act even in the presence of blood and other tissue exudates.
• It has a definite characteristics of producing ca ions, resulting in less leakage at the capillary junction.
• It causes contraction of the pericapillary sphincters, thus resulting in less plasma outflow. Hence, it is the
material of choice for weeping canals.

CALCIUM HYDROXIDE IN APEXIFICATION
• In apexification technique canal is cleaned and disinfected, when tooth is free of signs
and symptoms of infection, the canal is dried and filled with stiff mix of calcium hydroxi
de and CMCP.
• Commercial paste of calcium hydroxide (eg. Calasept, Pulpdent, Hypocal, Calyxl) may
be used to fill the canals.
• Histologically →formation of osteodentin after placement of calcium hydroxide paste

• There appears to be a differentiation of adjacent connective tissue cells; there is also deposition
of calcified tissue adjacent to the filling material.
• The calcified material is continuous with lateral root surfaces, the closure of apex may be partial
or complete but consistently has minute communications with the periapical tissue.

Time required for apical barrier formation in apexification using calcium hydroxide
Sheehy and Roberts 1997 an average length of time for apical barrier formation ranging from 5
to 20 months
Finucane and Kinirons 1991 calcium hydroxide apexification and found that the mean time to
barrier formation was 34.2 weeks (range 13–67 weeks)
Cvek 1972 infection and/or the presence of a periapical radiolucency at the start
of
treatment increases the time required for barrier formation
Kleier and Barr 1991 presence of symptoms the time required for apical closure was
extended by approximately 5 months to an average of 15.9 months

Apexification with the use of calcium hydroxide
(R Nahar,2012)
calcium hydroxide dressings is a justified alternative for the
biological sealing of an extensive foraminal opening, with conco
mitant repair of periapical lesions and continued calcific barrier
formation.
Successful closure of the root apex in non-vital permanent inciso
rs with wide open apices using single calcium hydroxide (caoh)
dressing
(NB Nagaveni,2010)
single application of CaOH dressing is sufficient to induce
apical barrier formation in young pediatric patients having pulpl
ess teeth with wide open apices.
Apexification with Calcium Hydroxide: 27 Months Follow Up
of a Case
(Chowdhury AFMA,2013)
calcium hydroxide has proven its ability in apical healing and
stop formation by stimulation of Hertwig’s epithelial root sheath
and(or) its remnants, the cell rests of Malassez. The extruded
material was also well accepted by the periradicular tissue.

CALCIUM HYDROXIDE AS AN INTRACANAL MEDICAMENT
✓ plays a major role as an inter-visit dressing in the disinfection of the root canal system.
✓ Calcium hydroxide is normally used as slurry of Calcium hydroxide in a water base.
✓ At body temperature less than 0.2% of Calcium hydroxide is dissolved into ca++ and OH- ions.

• Direct contact experiments in vitro require a 24 hour contact period for complete kill of enterococci.
• Calcium hydroxide not only kills bacteria, but it also reduces the effect of the remaining cell wall mat
erial lipo-polysaccharide.
• It should be mixed to a thick mixture to carry as much Calcium hydroxide particles as possible. This
slurry is best applied with a lentulo-spiral.

• calcium hydroxide→ ability to dissolve necrotic tissue (periapical infection)
• Calcium hydroxide is now widely used to reduce the seepage of apical fluids into the canal
so as to allow the placement of a satisfactory root filling.
• The mechanism whereby the reduction of seepage occurs is probably due to the fibrous
barrier that is formed when calcium hydroxide is placed in direct contact with host tissues,
or to the contraction of capillaries, as suggested by Heithersay, or simply to the effect of
mechanical blockage.

CALCIUM HYDROXIDE AS AN ENDODONTIC SEALER
• Calcium hydroxide must be dissociated into Ca++ and OH-. Therefore to be effective, an endodontic
sealer based on calcium hydroxide must dissolve and the solid consequently lose content.
• One major concern is that the calcium hydroxide content dissolve, leaving obturation voids.
• This would ruin the function of the sealer, because it would disintegrate in the tissue.
• Recent uses → sealapex(kerr), apexkit(vivadent).

• Comparative studies reveal their mild cytotoxicity, but their antibacterial effects are variable.
• Further research is required to establish the tissue healing properties of calcium hydroxide in
root canal sealers.

OTHER CLINICAL APPLICATIONS OF CALCIUM HYDROXIDE
Horizontal root fractures
✓ first recommended by Cvek (1974)
✓ proposed that → the canal at the level of the fracture line was comparable to the apical foramen of an
immature tooth. Thus, he assumed that the repair would be similar to the apexification procedure
employed for a tooth with an open apex.
✓ drawback → chair-side time and the frequent refilling of the canal with calcium
hydroxide
✓ A better alternative treatment protocol is now available with use of MTA

Perforations
• It has been suggested that large apical perforations should be treated in a similar way as teeth
with immature apices, i.e. with long-term Ca(OH)2 treatment to achieve a hard-tissue barrier.
• El Deeb et al. and Himel et al.(1985) expressed concerns about using Ca(OH)2 in close proximity
to the attachment apparatus because of the necrotizing properties of the material and the
inflammatory reaction to it.
• MTA widely used

Root resorption
• Frank & Weine reported on a technique using a Ca(OH)2- camphorated monochlorophenol
mixture for the nonsurgical treatment of perforating internal resorption.
• In such situations, other similar techniques have been used that resulted in the deposition of a
cementum-like or osteoid tissue.
initial treatment of choice → for internal root resorption is to pack the canal and 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.
• Ca(OH)2 should be placed into the resorptive defect at 3-month intervals until there is evidence
of hard-tissue repair

• When external resorption occurs following luxation injuries pulp extirpation, debridement and
Ca(OH)2 therapy are necessary.
• In some situations when root resorption continues after the completion of active and retentive
phases of orthodontic treatment, intentional pulp extripation and Ca(OH)2 is often successful in
abating resorption.
• Andreasen was able to arrest inflammatory root resorption in nine of ten cases using an
intracanal Ca(OH)2 dressing.

Conclusion
• Calcium hydroxide has been around the century and the research surround it’s properties and use, has
increased dramatically in the recent years. Many newer materials are now available in the market,
which claim to be superior to calcium hydroxide.
• When compared to the prices of the newer materials calcium hydroxide is more cost effective. Some
preparations of calcium hydroxide are still, expensive but a simple calcium hydroxide powder and
sterile water can serve many purposes and works out to be reasonable and affordable to many patients.
• Hence calcium hydroxide has become one of the most widely accepted materials and remedy to most
of the problems due to its high pH and Antibacterial property.

Calcium hydroxide in pediatric dentistry

Calcium hydroxide in pediatric dentistry

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