The document discusses various root canal obturation techniques and materials. It describes the monoblock concept of creating a continuous solid layer from the dentin wall to the core filling material. Resilon and Epiphany sealer are introduced as alternatives to gutta-percha that form a monoblock unit due to adhesion. Other techniques discussed include EndoREZ points coated with resin, ActivGP which uses glass ionomer to coat gutta-percha, and Smartseal which uses hydrophilic polymer points that expand to fill voids. Mineral trioxide aggregate is also summarized due to its biocompatibility and uses including pulp capping and root repair.

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Recent trends in root canal obturation
In recent years, there has been an increasing concern about the poorsealing
properties of the conventional root-filling materials, gutta-percha and the different
sealers . Many studies have demonstrated microleakage in canals filled with these
materials that may allow ingress and propagation of bacteria resulting in infection
. In responseto the shortcomings of gutta-percha recent introduction of an
alternative root filling material offers the promise of adhesion to root canal dentine
The MonoblockConcept
An ideal endodontic filling material should create a“monoblock”. This term refers
to a continuous solid layer that consists of an etched layer of canal dentin
impregnated with resin tags which are attached to a thin layer of resin cement

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that is bonded to a corelayer of resilon which makes up the bulk of the filling
material. In other words the monoblock conceptmeans the creation of a solid,
bonded, continuous material from one dentin wall of the canal to the other.
One added benefit of the monoblock is that research has shown that it strengthens
the root by approximately 20 percent.
Classification of Monoblockconcept based on number of interfaces present
between corefilling material and bonding substrate:
Primary: In this obturation is completely done with core material, for example, use
of MTA for obturation in cases of apexification.
Secondary: In this bond is there between etched dentin of canal wall impregnated
with resin tags which are attached to resin cement that is bonded to corelayer, e.g.
resilon based system.
Tertiary: In this conventional gutta-percha surface is coated with resin which bond
with the sealer, which further bond to canal walls, e.g. Endo Rez and Activ GP
system.

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Resilon
Resilon has been developed to replace gutta-percha and traditional sealers for root
canal obturation.It offers solutions to the problems associated with guttapercha:
1. Shrinkage of gutta-percha after application of heat.
2. since gutta-percha does not bind physically to the sealer, it results in gap
formation between the sealer and the gutta-percha.
This resilon core material bonded to the sealer by polymerization. When it sets, no
gaps are seen due to shrinkage.
Resilon system is comprised of the following components:

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1. Primer: It is a self etch primer, which contains a sulfonic acid terminated
functional monomer, HEMA (hydroxyethyl methacrylate), water and a
polymerization initiator. conditions the dentinal surface of root canals,
demineralizing it,and exposing the collagen matrix
2. Resilon sealer (Epiphany) a dual-cured, resin-based composite sealer. bonds to
both the root dentin and Resilon cones.
The resin matrix is comprised of Bis-GMA ((bisphenylglycidyl dimethacrylate),
ethoxylated Bis-GMA, UDMA (urethane dimethacrylate,) , and hydrophilic
difunctional methacrylates. It contains fillers of calcium hydroxide, barium
sulphate, bioactive glass, bismuth oxychloride and silica. The total filler content is
approximately 70 percent by weight. The preparation of the dentin through these
chemical agents may prevent shrinkage of the resin filling away form the dentin
wall and aid in sealing the roots filled with resilon material.The second generation
of methacrylate sealer replaced the original by the introduction of the Epiphany SE
Self-Etch Sealer a self-etch dual-cure, hydrophilic resin sealer that bonds to both
Resilon and dentin, without a separate priming step
3. Resilon core material: It is a thermoplastic synthetic polymer based (polyester)
root canal core material that contains bioactive glass, bismuth oxychloride and
barium sulphate. The filler content is approximately 65 percent by weight.

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This new material has shown to be biocompatible, noncytotoxic and
nonmutagenic. The excellent sealing ability of the resilon system may be attributed
to the “mono block” which is formed by the adhesion of the resilon cone to the
Epiphany sealer, which adheres and penetrates into the dentin walls of the root
canal system. The material is clinically used exactly like gutta-percha in that it can
be applied with warm and cold obturation techniques
EndoREZ
EndoREZ (ER) is a hydrophilic, two-component (base and catalysts), dual-
curing self priming sealer. based on the urethane dimethacrylate (UDMA)
molecule.EndoREZ has hydrophilic characteristics providing penetration into
dentinal tubules. The radiopacity is equivalent to gutta-percha, providing
simplified radiographic interpretation. EndoREZ does not compromise the
function of dentin bonding agents or luting resin polymerization.
EndoREZ is designed to be used with EndoREZ Points and/or gutta percha for
the filling of cleaned and shaped root canals. EndoREZ, in conjunction with a

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master cone and accessorycone, provides optimum sealing. Although Endo-
REZ Points are recommended, EndoREZ may be used with all conventional
endodontic obturation techniques.
EndoREZ Points are standard ISO-sized gutta percha points overlayed with a
thin resin coating, which bonds chemically with EndoREZ sealer and other
resin-based sealers.
The EndoREZ obturation system with single or multiple EndoREZ Points
creates a solid, ideal seal &true monoblock in the canal space
Activ GP
This system is composedofa core material containing gutta-percha which is
impregnated and coated on its external surface with glass ionomer. The
accompanying sealer is a traditional glass ionomer sealer which can adhere
chemically and micromechanically to the Activ GP cones and bond to the
dentin.Glass ionomer–based sealers had been developed based on glass
ionomers’ high affinity for bonding to dentin. Coating Activ GP with
glass ionomer particles is done to overcome the drawback of inadequate
bonding between gutta-percha and glass ionomer sealer.
• Activ GP Sealer has been formulated with an extended 12 minute working
time, giving you the necessary time to place the material.

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• The natural adhesion of Glass Ionomer to dentin (ionic bond)means there’s
no need for a bonding agent (primer) and the associated application technique
challenges.
Chemical and micromechanical adhesion between the canal walls, the Activ GP
sealer and the Activ GP gutta percha points results in a monoblok within the
canal, completely sealing the canal from orifice to apex.
Smartseal
Smartseal is a recently introduced rootcanal obturating system based on polymer
technology. Its principle is based on the hydrophilic nature of the obturating points
which can absorb surrounding moisture and expand resulting in filling of
voids and spaces.
Smartseal is a single point and sealer obturation system & constructed in two parts:
Central Core - this provides the point with the flexibility to allow it to easily pass
around any curves in the prepared canal, while being rigid enough to pass easily to
length in narrower canals.
Outer Polymer Layer - this hydrophilic, hydrogel layer allows the point to swell
in order to adapt to the ramifications of the root canal.

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Any--:Advantages of using hydrogels over existing obturation materials are
geometry of point can be accurately made
-Controlled expansion - Biocompatibility
sealis a hydroxyapatite based sealer that is used with the smartpaste BioSmart
obturation points. The sealer is delivered in a pre-mixed syringe and is simply
injected into the root canal. The sealer will expand slightly on setting and provides
a highly biocompatible alternative to traditional endodontic sealers.
Any Shape is Possible.
a system has been developed which allows the hydrogel coating on the propoints to
be cast to accurately match the shape of the canal prepared with any file system.
Currently the prosmart range includes points in 4 and 6% tapers, and points
engineered to fit the finishing files in the ProTaper™ and Sendoline™ S5 systems.
However the versatility of the productallows us to create points to match every file
system, past, present or future....
Controlled Expansion
The smartseal polymer is hydrophilic which allows the minute amount of water
present in the root canal to be absorbed bythe points. This water can hydrogen
bond to the polar sites present, enabling expansion within the polymeric chains.
The rate and extent of this expansion is controlled as part of the manufacturing
process. Known as Hydrogels, polymers like smartseal, expand with a miniscule
force that is well below the reported tensile stress of dentine and a fraction of the
force generated when using traditional techniques such as warm vertical
compaction. This gentle expansion occurs within the first 4 hours after placing the
point into the canal and allows the point to gently adapt to any irregularities in the
root canal. This results in the polymer and sealer being expressed into the dentinal

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tubules. The slight positive pressure against the canal wall that is created forms a
seal that is virtually impermeable to bacterial micro-leakage.
The impermeability of the seal is effectively demonstrated in the following images
from dye penetration studies. The dye is able to pass into the dentine but is
completely prevented from passing into the root canal spaceoccupied by the
prosmart point.
MINERAL TRIOXIDE AGGREGATE (MTA)
Developed by Dr Torabinejad at Loma Linda University in 1993.
Composition
It is available in two colors White and Gray color
Gray color
– It contains tricalcium silicate,
– Dicalcium silicate,
– Tricalcium aluminate
– Bismuth oxide
– Calcium sulfate
– Tetracalcium aluminoferrite
White color: It has same composition as that of gray color MTA except the lack of
tetracalcium aluminoferrite. Thus, it is white in color
Properties
1. pH of MTA is 12.5 (When set) so, it has biological and
histological properties similar to calcium hydroxide.
2. Setting time is 2 hours and 45 minutes.
3. Compressive strength is 40 MPa immediately after setting and 70 MPa after 21
days
4. Contrast to Ca(OH)2, it produces hard setting nonresorbable surface

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5. It sets in a moist environment (hydrophilic in nature).
6. It has low solubility.
7. It shows resistance to marginal leakage.
8. It also reduces bacterial migration.
9. It exhibits excellent biocompatibility in relation with vital tissues.
10. The compressive strength of MTA is equal to IRM and
SuperEBA but less than that of amalgam.
11. MTA is also known as Portland’s cement except for
addition of bismuth oxide which is added for modifying
its setting properties. Its consistency is similar to very hard
cement, which can be compared to concrete.
Commercially it is available under the name ProRootMTA (Dentsply).
Advantages of MTA
1. Water based chemistry, so requires moisture for setting
2. Excellent biocompatibility
3. Normal healing responsewithout inflammation
4. Least toxic of all the filling materials
5. Reasonably radiopaque
6. Bacteriostatic in nature
7. Resistance to marginal leakage.
Disadvantages of MTA
1. Difficult to manipulate
2. Long setting time (3-4 hours)
3. Costly.
f use of MTAIndications o
1. As a pulp capping material.
2. Forthe repair of root canals as an apical plug during apexification.

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3. Forthe repair of root perforations during root canal therapy.
4. Forthe repair of root resorptions.
5. As a root-end filling material.