Obturation of the cleaned

and shaped root canal

system
Success in endodontic treatment was originally based
on the triad of debridement, thorough disinfection, and
obturation with all aspects equally important

At present, successful root canal treatment is based on

broader principles
Diagnosis and treatment planning

Knowledge of anatomy and morphology

The traditional concepts of debridement

Thorough disinfection, and obturation

The coronal restoration

Obturation is a reflection of the cleaning and shaping
and is evaluated on the basis of;

• Length

• Taper

• Density

• Level of gutta-percha removal

• The coronal seal

Obturation reduces coronal leakage and bacterial
contamination

Seals the apex from the periapical tissue fluids

Entombs the remaining irritants in the canal

Timing of obturation
 Vital pulp tissue
At present the consensus is that one-step treatment procedures
are acceptable when the patient exhibits a completely or partially
vital pulp

Removal of the normal or inflamed pulp tissue and performance of

the procedure under aseptic conditions should result in a
successful outcome because of the relative absence of bacterial
contamination

Obturation at the initial visit also precludes contamination as a

result of leakage during the period between patient visits
 Necrotic pulp tissue
Patients who present with pulp necrosis with or
without asymptomatic periapical pathosis may be
treated in one visit, based on the best available
information

When patients present with acute symptoms caused by

pulp necrosis and acute periradicular abscess,
obturation is generally delayed until the patient is
asymptomatic
In general, obturation can be performed after cleaning and
shaping procedures when the canal can be dried and the
patient is not experiencing swelling

An exception is the presence or persistence of exudation

from the canal

Obturation of a canal that cannot be dried is

contraindicated

A few studies suggest that complete cleaning and shaping

should be accomplished and calcium hydroxide placed as
an antimicrobial and temporary obturant in necrotic cases
that cannot be treated in one visit
 Length of the obturation
One of the controversies in endodontics that remains
unresolved is the apical limit of root canal treatment
and obturation

Early studies identified the dentinocemental junction as

the apical limit for obturation

However, this histologic landmark cannot be

determined clinically , and it has been found to be
irregular within the canal
Traditionally , the apical point of termination has been
approximately 1 mm from the radiographic apices as
determined by radiographs

Kuttler noted that the apical anatomy consists of the major

diameter of the foramen and the minor diameter of the
constriction, with the apical constriction identified as the
narrowest portion of the canal

The average distance from the foramen to the constriction was

found to be 0.5 mm, with the foramen varying in distance from
the apex up to 2.5 mm

Kuttler also noted that the foramen-to-constriction distance

increases with age because of cementum deposition
Another study found that, in necrotic cases, better success
was achieved when the procedures terminated at or
within 2 mm of the radiographic apex

Obturation shorter than 2 mm from the apex or past the

apex resulted in a 20% lower success rate

For vital cases, termination between 2 and 3 mm was

acceptable

Other investigators found that teeth obturated less than 2

mm from the apex had a higher success rate when
compared with cases obturated more than 2 mm from the
apex
 Preparation for obturation

During the cleaning and shaping process, organic pulpal

materials and inorganic dentinal debris accumulate on the
canal wall, producing an amorphous irregular smear layer

The smear layer is superficial, with a thickness of 1 to 5 µm,

and this superficial debris can be packed into the dentinal
tubules to various distances

In cases of necrosis this layer may also be contaminated with

bacteria and their by-products
There is controversies about removing or leaving the
smear layer

A new method for removing the smear layer employs

the use of a mixture of a tetracycline isomer, an acid,
and a detergent (MTAD) as a final rinse to remove the
smear layer

MTAD removes most of the smear layer; however,

some organic components of the smear layer remains
on the surface of the root canal walls
After the completion of cleaning and shaping
procedures, removal of the smear layer is generally
accomplished by irrigating the canal with 17% disodium
EDTA and 5.25% NaOCl

Chelators remove the inorganic components, leaving

the organic tissue elements intact

NaOCl is necessary for removal of the remaining

organic components

Fifty percent citric acid has also been shown to be an

effective method for removing the smear layer, as has
tetracycline
 The ideal root canal filling

Various endodontic materials have been advocated for

obturation of the radicular space

Most techniques employ a core material and sealer

Regardless of the core material a sealer is essential to

every technique and helps achieve a fluid-tight seal
 Sealers

Root canal sealers are necessary to seal the space between

the dentinal wall and the obturating core interface

Sealers also fill voids and irregularities in the root canal,

lateral and accessory canals, and spaces between gutta-
percha points used in lateral condensation

Sealers also serve as lubricants during the obturation

process
Exhibits tackiness when mixed to provide good adhesion
between it and the canal wall when set

Establishes a hermetic seal

Radiopaque, so that it can be seen on a radiograph

Very fine powder, so that it can mix easily with liquid

No shrinkage on setting

No staining of tooth structure

Bacteriostatic, or at least does not encourage bacterial
growth

Exhibits a slow set

Insoluble in tissue fluids

Tissue tolerant; that is, nonirritating to periradicular

tissue

Soluble in a common solvent if it is necessary to remove

the root canal filling
 Zinc Oxide and Eugenol

Zinc oxide–eugenol sealers will absorb if extruded into

the periradicular tissues

They exhibit a slow setting time, shrinkage on setting,

solubility, and they can stain tooth structure

An advantage to this sealer group is antimicrobial

activity
 Calcium Hydroxide Sealers

Calcium hydroxide sealers were developed for therapeutic

activity

It was thought that these sealers would exhibit antimicrobial

activity and have osteogenic–cementogenic potential

Unfortunately , these actions have not been demonstrated

Solubility is required for release of calcium hydroxide and

sustained activity
Caclibiotic Root Canal Sealer (CRCS)

Sealapex

Apexit

Apexit Plus
 Glass Ionomer Sealer
The glass ionomers have been advocated for use in obturation because
of their dentin-bonding properties

Ketac-endo enables adhesion between the material and the canal wall

This sealer has minimal antimicrobial activity

Activ GP consists of a glass ionomer–impregnated gutta-percha cone

with a glass ionomer external coating and a glass ionomer sealer

This single cone technique is designed to provide a bond between the

dentinal canal wall and the master cone (monoblock)
 Resin sealers

Resin sealers have a long history of use, provide

adhesion, and do not contain eugenol
AH-26 was one of the first resin sealers introduced to
the market

Unfortunately it release formaldehyde upon setting

It was then replaced by modified formulation of AH-26

in which formaldehyde is not released

It has a long working time of about 4 hours

EndoREZ, Diaket, Epiphany, ReaSeal, and Adseal

 Sealer placement

The master cone

Lentulo spirals

Files and reamers

Ultrasonics
 Core materials
Although a variety of core materials have been used in
conjunction with a sealer/cement, the most common
method of obturation involves gutta-percha as a core
material

Solids, semisolid materials, and pastes have been

employed

A common solid material was the silver cone

 Silver cones
Jasper introduced cones made of silver, which he claimed produced
the same success rate as gutta-percha and were easier to use

Rigidity (easy to place and permitted more predictable length

control)

Inability to fill the irregularly shaped root canal system (leakage)

When silver points contact tissue fluids or saliva, they corrode

The corrosion products have been found to be cytotoxic and

produced pathosis or impeded periapical healing
 Gutta percha
Advantages

Plasticity

Ease of manipulation

Minimal toxicity

Radiopacity

Ease of removal with heat or solvents

Disadvantages

Lack of adhesion to dentin

When heated, shrinkage on cooling

Gutta-percha is the trans isomer of polyisoprene
(rubber) and exists in two crystalline forms (α and β)

In the unheated β phase the material is a solid mass

that is compactable

When heated the material changes to the α phase and

becomes pliable and tacky and can be made to flow
when pressure is applied
Gutta-percha cones consist of approximately;

20% gutta-percha

65% zinc oxide

10% radiopacifiers

5% plasticizers
Gutta-percha can be made to flow if it is modified by either heat or
solvents such as chloroform

This permits adaptation to the irregularities of the canal walls

The α form of gutta-percha melts when heated above 65° C

When cooled extremely slowly , the α form will recrystallize

Routine cooling results in the recrystallization of the β form

Although the mechanical properties for the two forms are the
same, when α-phase gutta-percha is heated and cooled it
undergoes less shrinkage, making it more dimensionally stable for
thermoplasticized techniques
Gutta-percha cones are available in standardized and non-
standardized (conventional) sizes

The nonstandard nomenclature refers to the dimensions of

the tip and body

A fine-medium cone has a fine tip with a medium body

Standardized cones are designed to match the taper of

stainless steel and nickel–titanium instruments

Although the points cannot be heat sterilized, a study found

that gutta-percha points can be sterilized before use by
placing the cones in 5.25% NaOCl for 1 minute
 Activ GP

Activ GP consists of gutta-percha cones impregnated on

the external surface with glass ionomer

Single cones are used with a glass ionomer sealer

Available in .04 and .06 tapered cones, the sizes are

laser verified to ensure a more precise fit
 Resilon

Resilon is a high performance industrial polyurethane

that has been adapted for dental use

The resin sealer bonds to a resilon core, and attaches to

the etched root surface

The manufacturer claims that this forms a “monoblock”

It consists of resin core material (resilon) composed of;

• Polyester

• Difunctional methacrylate resin

• Bioactive glass

• Radiopaque fillers

• Resin sealer

Resilon is nontoxic, nonmutagenic, and biocompatible

The core material is available in nonstandard and standard

cones and pellets for use in thermoplastic techniques
Methods of obturation
 Lateral compaction

After canal preparation a standard cone is selected that

has a diameter consistent with the prepared canal
diameter at the working length
The master cone placement is confirmed with a
radiograph

The canal is irrigated and dried with paper points

Sealer is applied to the canal walls, and a spreader is

prefitted so as to allow it to be inserted to within 1.0 to
2.0 mm from working length

Appropriate accessory points are also selected to

closely match the size of the spreader
The spreader should fit to within 1 to 2 mm of the prepared length,
and when introduced into the canal with the master cone in place, it
should be within 2 mm of the working length

There appears to be a correlation between establishing a seal and

spreader penetration

After placement the spreader is removed by rotating it back and forth

as it is withdrawn

An accessory cone is placed in the space vacated by the instrument

The process is repeated until the spreader no longer goes beyond the
coronal one third of the canal

The excess gutta-percha is removed with heat and the coronal mass is
compacted with an appropriate plugger
 Warm vertical compaction

Schilder introduced warm vertical compaction as a

method of filling the radicular space in three
dimensions

The technique involves fitting a master cone short of

the corrected working length (0.5 to 2 mm) with
resistance to displacement
After the adaptation of the master cone it is removed
and sealer is applied

The cone is placed in the canal and the coronal portion

is removed with heat

A heated spreader or plugger is used to remove

portions of the coronal gutta-percha and soften the
remaining material in the canal

The Touch 'n heat, EI DownPak, and System B are

alternatives to applying heat with a flame-heated
instrument because they permit temperature control
A plugger is inserted into the canal and the gutta-
percha is compacted, forcing the plasticized material
apically

The process is repeated until the apical portion has

been filled

The coronal canal space is back-filled, using small pieces

of gutta-percha

The sectional method consists of placing 3- to 4-mm

sections of gutta-percha approximating the size of the
canal into the root, applying heat, and compacting the
mass with a plugger
Continuous wave technique

Is a variation of warm vertical compaction

After selecting an appropriate master cone, a plugger is

pre-fitted to fit within 5 to 7 mm of the canal length
The System B unit is set to 200° C in the touch mode. The
plugger is inserted into the canal orifice and activated to
remove excess coronal material

Compaction is initiated by placing the cold plugger

against the gutta-percha in the canal orifice

Firm pressure is applied and heat is activated with the

device

The plugger is moved rapidly (1 to 2 s) to within 3 mm of

the binding point

The heat is inactivated while firm pressure is maintained

on the plugger for 5 to 10 seconds
Filling the space left by the plugger can be
accomplished by a thermoplastic injection technique or
by fitting an accessory cone into the space with sealer,
heating it, and compacting by short applications of
heat and vertical pressure

After the gutta-percha mass has cooled a 1-second

application of heat separates the plugger from the
gutta-percha, and it is removed
Warm lateral compaction

Lateral compaction of gutta-percha provides for length

control, which is an advantage over thermoplastic
techniques

The Endotec II device provides the clinician with the

ability to employ length control while incorporating a
warm gutta-percha technique
The warm lateral compaction technique involves adapting a
master cone in the same manner as with traditional lateral
compaction

An appropriate-size Endotec II tip is selected

The device is activated and the tip is inserted beside the master
cone to within 2 to 4 mm of the apex, using light pressure

The tip is rotated for 5 to 8 seconds and removed

An unheated spreader can be placed in the channel created to

ensure adaptation and then an accessory cone is placed

The process is continued until the canal is filled

 Thermoplastic injection
technique

Heating of gutta-percha outside the tooth and injecting

the material into the canal is an additional variation of
the thermoplastic technique

The Obtura II system heats the gutta-percha to 160° C,

whereas the Ultrafil 3D system employs a low-
temperature gutta-percha that is heated to 90° C
 Obtura III

The Obtura III system consists of a hand-held “gun” that

contains a chamber surrounded by a heating element into
which pellets of gutta-percha are loaded

Silver needles are attached to deliver the thermoplasticized

material to the canal

The control unit allows the operator to adjust the

temperature and thus the viscosity of the gutta-percha
 Ultrafil 3D
Ultrafil 3D is a thermoplastic gutta- percha injection technique
involving gutta-percha cannulas, a heating unit, and an injection
syringe

The system employs three types of gutta-percha cannulas

The regular Set is a low-viscosity material that requires 30

minutes to set

The Firm Set is also a low-viscosity material but differs in that it

sets in 4 minutes
 Calamus

The Calamus flow obturation delivery system is a

thermoplastic device equipped with a cartridge system
with 20- and 23-gauge needles

The unit permits control of temperature and also the

flow rate

Pluggers are also available for use with the system

 Elements

The elements obturation unit consists of a System B

heat source and plugger as well as a handpiece
extruder for delivering thermoplastic gutta-percha or
realSeal from a disposable cartridge
 HotShot

The HotShot delivery system is a cordless thermoplastic

device that has a heating range from 150° C to 230° C

The unit is cordless and can be used with either gutta-

percha or resilon
 GuttaFlow
It consists of a cold, flowable matrix that consists of
polydimethylsiloxane matrix filled with very finely ground gutta-
percha

The material is provided in capsules for trituration in an

amalgamator

The technique involves injection of the material into the canal

and placing a single master cone to length

The material provides a working time of 15 minutes and it cures

in 25-30 minutes
 Carrier based gutta percha

Thermafil

Profile GT Obturators

GT Series X Obturators

ProTaper Universal Obturators

Thermafil was introduced as a gutta-percha obturation
material with a solid core, originally manufactured with
a metal core and a coating of gutta-percha, the carrier
was heated over an open flame

The technique was popular because the central core

provided a rigid mechanism to facilitate the placement
of the gutta-percha
Advantages included ease of placement and the pliable
properties of the gutta-percha

Disadvantages were that the metallic core made

placement of a post challenging and retreatment
procedures were difficult

In addition, the gutta-percha was often stripped from

the carrier, leaving the carrier as the obturating
material in the apical area of the canal
After drying the canal a light coat of sealer is applied
and a carrier is marked, set to the predetermined
length

The carrier is disinfected with 5.25% NaOCl for 1

minute and rinsed in 70% alcohol

The carrier is then placed in the heating device

When the carrier is heated to the appropriate

temperature the clinician has approximately 10 seconds
to retrieve it and insert it into the canal
The position of the carrier is verified radiographically

The gutta-percha is allowed 2 to 4 minutes to cool

before resecting the coronal portion of the carrier,
which can be several millimeters above the canal orifice

This is accomplished by applying stabilizing pressure to

the carrier and cutting the device with an inverted
cone, round bur, or a specially designed Prepi bur
 Successfil
It is a carrier-based system associated with Ultrafil 3D; however, the gutta-percha
used in this technique comes in a syringe

Carriers (titanium or radiopaque plastic) are inserted into the syringe to the
measured length of the canal

The gutta-percha is expressed on the carrier, with the amount and shape determined
by the rate of withdrawal from the syringe

Sealer is lightly coated on the canal walls, and the carrier with gutta-percha is placed
in the canal to the prepared length

The gutta-percha can be compacted around the carrier with various pluggers
depending on the canal morphology

This is followed by severing of the carrier slightly above the orifice with a bur
 Thermomechanical
compaction
McSpadden introduced an instrument, the McSpadden Compactor,
with flutes similar to a hedström file but in reverse

When activated in a slow-speed handpiece the instrument would

generate friction, soften the gutta-percha, and move it apically

Rotary compactors similar in design have been developed and

advocated

To increase flexibility the instrument is available in nickel–titanium

Advantages:

• Simplicity of the armamentarium

• The ability to fill canal irregularities

• Time saving

Disadvantages:

• Possible extrusion of material

• Instrument fracture

• Gouging of the canal walls

• Inability to use the technique in curved canals

• Heat generation
Thank you