Calcium hydroxide and MTA
CALCIUM HYDROXIDE &
MTA (Mineral trioxide aggregate)
MTA (Mineral trioxide aggregate)
INTRODUCTION
Calcium cements are relatively weak cements
Calcium hydroxide is a white odorless powder which is mixed
with water to a paste.
Due to their alkaline nature they serve as a protective
barrier against irritants from certain restorations. pH 12.2
MECHANISM OF ACTION
Exact mechanism of action is still not known.
Calcium hydroxide maintains
a local state of alkalinity that
is necessary for bone/dentin formation .
High alkaline pH(11-13) causes neutralization of acids
produced by microorganisms.
Biochemical Actions
Ca(OH)2 has the unique potential to induce
mineralization, even in tissues which have not been programmed to mineralize.
The mechanism by which Ca(OH)2 initiates the
reparative process is unclear.
It has been suggested that a rise in pH as a result of the free
hydroxyl ions may initiate mineralization.
Ca(OH)2 may also act as a local buffer against the
acidic reactions produced by the inflammatory process.
An alkalinic pH may also neutralize the lactic acid, secreted
by osteoclasts, and this may help to prevent further destruction of mineralized
tissue.
The high pH àmay activate
alkaline phosphatase activity, which is postulated to play an important role in
hard tissue formation.
Dentine bridge
A mineralized barrier usually produced following application
of Ca(OH)2 to a vital pulp
This repair material appears to be a product of odontoblasts
and Connective tissue cells.
Considerably reduces the permeability of exposed dentin for
penetration of bacterial components towards the pulp.
This may be due
to
Coagulation of
proteins in dentinal tubules
Due to
secondary dentin formation
It has an antibacterial effect
Calcium hydroxide has a strong antibacterial effect on the
contaminated soft carious dentin.
Low grade irritation due to coagulative necrosis caused by
calcium hydroxide leading to hard tissue differentiation in the pulp to calcify
barrier formation.
AVAILABILITY
Powder form (mixed with distilled water)
Two paste system containing base and catalyst pastes in
collapsible tubes.
Light cured system
Single paste in syringe form (pulpdent).
Light cured two paste system
Setting pastes
The therapeutic properties of the setting CaOH2 materials are
related to their pH.
Strong effect:
Dycal (original formula)
Reocap
Procal
Medium effect:
Dycal (New formula)
Life
Renew
Reolit.
No effect:
M.P.C.
Hydrex
Cal-Mer- VII
Non setting pastes
Analar Ca(OH2) – H2O
Pulp dent methyl cellulose
Hypocal methyl cellulose
Reogan methyl cellulose
Visible light activated calcium hydroxide – Single paste
system.
Calcium hydroxide
Barium sulphate
UDMA Resin
Camphoroquinone (photoinitiator)
SLOW SETTING calcium
hydroxide Pastes.
-mainly used as root Canal Sealer materials
Calcium hydroxide can be used as a sealer to coat the pulp space and form a hermetic seal
Ex – Calcibiotic
sealer
VEHICLES
When calcium
hydroxide powder is mixed with a suitable vehicle a paste is formed.
Mainly three types of Vehicles are used
Aqueous Vehicles –
Water: Sterile
Distilled
Viscous Vehicles
- Glycerine
Polyethyl glycol
Oily vehicles -
Olive Oil
Fatty acids.
Eugenol.
Commercial names :
Self cured : dycal,
Life, Care, calcidor
Light cured:
Prisma VLC dycal
Thermal properties :
If used in sufficiently thick layers, they provide some
thermal insulation. However a thickness greater than 0.5mm is not recommended.
Thermal protection should be provided with a separate base.
MANIPULATION
Simply powder is carried to the cavity. Little wetness in the
cavity will be sufficient for calcium hydroxide to get adapted to the floor.
Calcium hydroxide is mixed with clean water and carried to
the cavity as a paste.
Equal length of both the pastes are taken on paper pad and
mixed to get a uniform color.
Material is taken, carried to the cavity and light cured. As
curing is done after adaptation, there is adequate time for use
MTA (mineral trioxide
aggregate)
CONTENTS
Introduction
Development
Applications
Composition and type
Clinical technique
Advantages
Limitations
MTA is a powder that
consists of fine hydrophilic particles that set in the presence of moisture.
Hydration of the
powder results in a colloidal gel that solidifies to a hard structure.
Development
— Research in
1990s in Loma Linda University by Torabinejad and associates.
— First
published by Torabinejad in 1993
— Introduced
as root end filling material
— As
furcation repair material by Pitt ford et al 1995
COMPOSITION
MTA
(Portland cement 75%)
(Portland cement 75%)
— Tricalcium
Silicate
— Dicalcium
Silicate
— Tricalcium
Aluminate
— Tetracalcium
Aluminoferrite
— Tricalcium
oxide
— Bismuth
Oxide – 20%
— Calcium
Sulfate Dihydrate (gypsum) – 5%
Types
1.
Grey MTA
2.
White MTA
Commercial Availability
PRO ROOT MTA
MTA ANGELUS
Grey MTA
White MTA
MTA ANGELUS
80% Portland cement + 20 % bismuth oxide
No gypsum
Calcium chloride
APPLICATIONS
WHY MTA ???
Superior sealing ability
Better root end seal
Ability to set even in presence of blood or moisture
Low solubility
Low toxicity
Bactericidal
Stimulate cementogenesis and dentinogenesis
No mutagenicity
Aid in periodontal regeneration
Biological response in osteoblastic cells
Reduced treatment time and patient appointments compared to
other materials
Properties
Micro leakage
Biocompatibility
Physical properties
Osteogenic potential
Antimicrobial properties
WHY LESS MICROLEAKAGE ?
— Fine
Hydrophilic propertiesà absorbs
water during hydration
— Expansion
leading to superior adaptation
BIOCOMPATIBILITY
Biocompatibility
— Important
property for clinical success
— Absence of
cytotoxicity when contacted with fibroblasts and osteoblasts
— Less inflammation
compared to calcium hydroxide
Physical Properties
— Initial PH
10.2 , Final PH 12.5
— Working
time 5 minutes
— Initial
Setting time 3 to 4 hrs
— Compressive
strength at 24 hrs – 40 mpa
— 21 days –
70 MPa
— Hydrophilic
- sets in the presence of moisture
Osteogenic Potential
Calcium present in abundance in the cement
When contacted with moisture
Calcium released reacts with phosphate
Calcium phosphate acts as hydroxy apatite crystal
Induce biological response in Osteoblastic cells due to adhesion
— Cytokines
increased like IL 4 and IL 10 or IL 1 alpha and IL 6
— Induces
Alkaline Phosphotase production
— Acts as a
scaffold for bone deposition
ANTI MICROBIAL
Release of hydroxyl ions
Increased PH
Unfavorable for bacterial growth
Manipulation
•
Open single pouch
•
Use entire contents of water ampule
•
P:L ratioà 3:1
•
Gradual mixing with sterile water
•
Hydrate all the powder
•
Add 1 to 2 drops of sterile water, if too stiff
•
Thick creamy consistency
•
Cover with moistened gauze to extend the working time
MTA CARRIERS
MTA PLUGGERS
Uses
1.Vital pulp therapy
Direct pulp capping
Pulpotomy
2.Perforation management
Furcation
Lateral
Apical
3.Apexification & Apexogenesis
4.Retreatment
Internal resorption
External resorption
5.Surgical
Retrograde root end filling
OTHERS
Vertical fractures
Coronal plug for internal bleaching
Obturation
PULP CAPPING
PULPAL REACTION
↓ (alkalinity)
↓
↓
↓
↓
PULPOTOMY
Success
— Induce hard
tissue formation at faster rate
— Thicker
dentin bridge, more frequent odontoblastic layer formation
— Greater
ability to maintain integrity of pulp than calcium hydroxide
— Less
inflammation
PERFORATION
MANAGEMENT
Radicular Perforation
INTERNAL RESORPTION
Internal Resorption
APEXIFICATION
SURGICAL
USES
Root end filling
LIMITATIONS OF MTA
Setting time is more
Expensive
Radiopacity higher than dentin
Difficult handling
Thank you..!
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