3. INTRODUCTION
According to the American Association of
Endodontists,”Obturation is the method used to fill and seal a
cleaned and shaped root canal using a root canal sealer or filling
material”.
Naidorf has stated that inadequate obturation of the root canal
exposes it to periradicular tissue fluids, which provide material
for growth of microorganisms or localization of bacteria in such
dead spaces.
4. According to a study by Ingle and Beveridge, 58% of endodontic
failures can be attributed to incomplete obturation of root canals
5. Grossman Requirements For An Ideal Root
Canal Filling Material
The material should be easily introduced into the root canal.
It should seal the canal laterally as well as apically.
It should not shrink after being inserted.
It should set slowly.
It should be impervious to moisture.
It should be bactericidal or, at least, should discourage the growth
of bacteria.
6. It should be radiopaque.
It should not stain the tooth structure.
It should not irritate periradicular tissues or affect the tooth
structure.
It should be sterile, or easily and quickly sterilized immediately
before insertion.
It should be easily removable from the root canal if necessary.
7. Objectives of Root Canal Filling
To seal the pulp chamber and root canal system from outer oral
environment.
To prevent passage of periapical exudate and microorganism to
the canals system.
To prevent gingival microorganism from passing into the root
canals via lateral canals (bacterial tight seal).
8. Timing Of Obturation
Clinical Criteria For Timing of Obturation
Patient Symptoms
If Patient presents with sensitivity on percussion , canal shouldnot
be obturated before inflammation has subsided.
The canal should be reasonably dry, with no “weeping” of fluids
in the form of bleeding or discharge of serous fluids.
Optimal shaping and cleaning of the canal can be easily achieved
in a tooth with vital pulp tissues.
9. When seepage into the root canal is excessive, it can be treated
and eliminated by reinstrumentation and enlarging the canal,
irrigating and sealing it with an intracanal medicament, such as
calcium hydroxide paste
Stringent clinical protocols should be adhered in such cases
before deciding the timing of the obturation.
10. Extent Of Obturation
According to Kuttler , “ Exit of the root
canal(major diameter) should be around
o.5mm short of the narrowest part of the
root canal(minor diameter)
As the minor diameter is the narrowest
part of the root canal closest to the exit of
the canal, it is clinically recommended to
limit the length of the obturation to this
point.
The location of the minor diameter or
apical constriction needs to be ascertained
by a combination of using radiographs,
electronic apex locator, and clinical
judgment of the clinician.
11. Endodontic Obturating Materials
1.Historical solid core obturating material
Silver points
2. Currently available solid core obturating materials
Gutta-percha
Mineral trioxide aggregate(MTA)
Resilon
12. Historical Solid Core Filling Materials
Silver Points
Introduced by Jasper in 1933
Stiffer than gutta-percha and can be easily
inserted into a fine,tortous canal
No longer recommended because of
following reasons:
Rigid and donot adapt to internal anatomy
of root canal
Corrodes when they come into contact with
saliva or periradicular fluids
13. Currently used solid core filling materials
Gutta-Percha
History
Hill(1847): Developed gutta-percha root canal filling known as “Hills
Stopping”
Bowman (1867) : Demonstrated the use of gutta-percha root canal filling
S.S. White Company (1887) : Manufacture of gutta-percha points
15. Characteristics
Rigid natural latex produced from the sap of rubber trees of genus
Palaquium gutta.
Trans-isomer of polyisoprene and exists in alpha and beta crystalline
forms.
On heating the material, beta phase changes into the alpha phase which
is tacky and flowable under pressure.
The solid mass alpha phase gutta-percha melts at a temperature above
65°C and turns into the beta phase on slow cooling.
16. Alpha phase gutta-percha : employed in thermoplasticized techniques,
while beta phase gutta-percha is more popular in lateral condensation
techniques.
Gutta-percha sterilization—As the gutta-percha points cannot be heat
sterilized, sterilization is recommended prior to use by placing in 5.25%
NaOCl for 1 minute.
17. Properties
Does not shrink after insertion unless it is plasticized with a solvent or
heat.
Easily sterilized prior to insertion and does not encourage bacterial
growth.
Radiopaque, nonstaining, and impervious to moisture.
Can be removed easily from the root canal if necessary.
Probably the least toxic and least irritating root canal filling material.
18. Sizes and Tapers
Available in conventional and standardized sizes
The conventional sizes include the following:
Extra fine
Fine
Medium Fine
Fine medium
Medium
Large
Extra large
19. Standarized sizes includes:
ISO 2 % from size Nos.15 to 140
Greater tapper gutta-percha cones
such as 4 or 6% tapered
Variable taper gutta-percha points
suiting the taper of variable taper
shaping instruments such as
ProTaper F1, F2 and F3
20. Mineral Trioxide Aggregate (MTA)
Indications :
According to Bogen et al :
MTA obturaton combined with root end resection
Teeth with open apices
Retreatment with MTA obturation
Dens in dente
21. Limitations :
Difficulty in retreatment following MTA obturation, especially in
curved canals
Potential for discoloration
MTA should not be used after irrigation with sodium hypochlorite as
this will result in tooth discoloration
22. Resilon
Resilon (Epiphany by Pentron Clinical Technologies or Real Seal by
SybronEndo) is a high-performance polyurethane
Composition of Resilon
It is a polycaprolactone core material with difunctional methacrylate
resin, bioactive glass, bismuth and barium salts as fillers, and pigments.
23. Protocol of Use
Can be placed using lateral compaction, warm vertical compaction, or
thermoplastic injection.
The core material is available in the form of ISO-sized points and
pellets for use with Obtura III (Obtura Spartan).
Resilon requires 150°C temperature for thermoplasticized techniques
which is less when compared to the 200°C temperature required by
normal gutta- percha.
25. 1. COLD LATERAL COMPACTION
TECHNIQUE
Most commonly practiced obturation
techniques.
Clinical Considerations
Sealer considerations:
The root canal is first dried with absorbent
paper points prior to the application of the root
canal sealer. Sealer application on the canal
walls can also be performed using a Lentulo
spiral or with the master gutta-percha cone
itself.
Fig: Absorbent paper points in the
canal
26. Spreader considerations
The size of the spreader is determined by the
width of the prepared canal and the lateral fit
of the primary cone; the greater the space
between the canal wall and the butt end of the
gutta-percha, the larger (wider) the spreader
used.
The spreader size should reach within 1-2 mm
of the working length. This can be ensured by
placing a silicon stopper on the spreader.
27. Master cone considerations
Selection of the master cone gutta-percha
should be similar to the master apical file
(MAF) size.
Minimal judicious force should be used on the
spreader during the compaction process .
Additional secondary gutta-percha cones are
inserted until the spreader cannot be
reinserted.
28. Several radiographs must be taken:
The fit of the primary cone is verified by
radiograph.
Another radiograph should be taken when
two or three secondary cones have been
condensed in the root canal to determine the
amount of flow and to avoid overfilling.
After verifying the fit of the obturated canal
by radiograph, the butt end of the gutta-
percha in the pulp chamber is cut off with a
hot instrument, the chamber is cleaned, and a
restoration is placed in the access cavity.
29. Technique of Cold Lateral Compaction
Isolation and drying the canal with paper points
Selection of master cone (same size as MasterApical File)
Checking for apical "TUG BACK"
Radiographic verification of master cone fit
30. Radiographic verification of master
cone fit
Inadequate fit -
Beyond the apex
At working length
Inadequate fit -
Short of the apex
If the master cone extends
beyond the working
length,
the tip should be cut off so
that the reinserted primary
cone fits snugly at the
working length or the next
larger size gutta-percha
cone is inserted and
verified radiographically.
Sealer
manipulation
and coat the
canal with sealer
using the master
cone or with a
lentulo spiral
If the initial fit is short of
the
working length, then
patency
has to be established to the
corrected length followed by
sequential irrigation,
recapitu
lation, and shaping of the
canalto the master apical file
size. Another primary gutta-
percha cone is fitted to the
corrected working length for
radiographic verification
31. Master cone inserted till working length and a hand or finger spreader is
inserted alongside the master cone to a level 1 mm short of the working length
The spreader is disengaged from the cone by rotating it between the
fingertips or by rotating the handle in an arc
Placement of sequential accessory cones by lateral compaction until
complete obturation of the radicular pulp space
Post obturation radiograph
32. Cold lateral compaction technique: (a) Root canal after completion of cleaning and
shaping. (b) Checking the fit of the spreader to be within 1 mm of the working
length. (c) Placement of the master cone. (d) Placement of spreader alongside the
master cone to a length 1mm short of the master cone to compact the apical part of
the cone. (e-h) Lateral compaction of additional cones sequentially.
33. Limitations
The presence of voids in between the filling
An increased sealer: gutta-percha ratio when compared with the
thermoplasticized techniques
Studies have also shown that warm compaction techniques have a
better ability to seal intracanal defects and lateral canals than cold
lateral compaction
34. A. Single Cone Obturation Technique
Uses a single cone of gutta-percha that is of similar tip diameter and
taper of the last shaping file used (MAF).
The root canal is obturated with a single cone of gutta-percha along
with an appropriate sealer.
Rationale
The introduction of Ni-Ti shaping systems has led to the
introduction of gutta-percha points that are matched in both tip
diameter and taper to various MAF sizes that each rotary/reciprocal
shaping system provides.
Currently, gutta-percha points of ISO 20, 25, 30, and above sizes are
available in not only 2% taper but also in 4 and 6% tapers .
35. 2. Warm Compaction Technique
( Warm gutta-percha)
A. Warm Vertical Compaction
Principle :
Introduced by Schilder with the objective of
filling the main root canal as well as lateral and
accessory canals.
Using heated pluggers, one applies pressure in
a vertical direction to the heat-softened gutta-
percha and thereby causes it to flow and to fill
the entire lumen of the canal.
36. Indications
As an alternative to the cold lateral compaction technique
When the fitting of a conventional master cone to the apical portion of a
canal is impossible, as when there is a ledge formation, perforation, or
unusual canal curvatures.
37. Technique
A primary nonstandardized or greater taper gutta-percha cone
corresponding to the last instrument (MAF) used is fitted in the
canal in the usual manner.
The canal wall is coated with a thin layer of root canal sealer.
The primary gutta-percha cone or master cone is inserted up to the
working length.
Warm vertical compaction technique can be divided into two
clinical steps:
Step 1: Down packing
Step 2 : Back filling
38. Step 1: Down packing
A "heat carrier, such as a root canal
plugger is heated to redness and is
immediately pushed into 3-4 mm of
the coronal third of the gutta-percha.
The heat carrier is deactivated and
removed after a pause of 2-3
seconds inside the canal. The
sheared gutta-percha gets removed
along with the heat carrier.
A vertical prefitted condenser or
plugger of suitable size is inserted,
and vertical pressure is applied to
the heated gutta-percha to force the
plasticized material apically.
39. The heat carrier is now again activated and placed to a further distance
of 3-4 mm into the remaining gutta-percha. This is again followed by
pausing and removing another segment of gutta-percha followed by
compacting the remaining gutta-percha with the next narrower sized
plugger as we proceed apically.
40. This process is repeated until the smallest plugger compacts the
gutta-percha to about 5 mm distance from the working length.
Care should be taken to not remove the apical 5 mm of gutta-percha
during the down-packing procedure for the following reasons:
The apical "cold" gutta-percha prevents the inadvertent extrusion
of the thermoplasticized gutta-percha beyond the working length.
The apical pressure is sufficient to seal the larger accessory
canals and fills the lumen of the canal in three dimensions up to
the apical foramen.
41. Step 2: Back filling
Can be achieved in two ways;
Schilder technique:
The remaining portion of the canal is plugged with additional
pieces of gutta- percha that is heated with the heat carrier and
then compacted with appropriate-sized pluggers.
Thermoplastic backfill technique:
This can be achieved with devices that heat gutta-percha to a
specific temperature and allow the operator to extrude the
thermoplastic gutta-percha into the canal apico-coronally.
42. 3-4 mm of the canal is filled then
backfill device is removed and the
plugger is used to compact the
gutta-percha.
This is repeated till the canal is
obturated completely till the canal
orifice.
Popular backfill devices include Obtura
III (Obtura Spartan), Elements Free
Obturation System
Obtura III
43. Warm vertical compaction technique: (a and b) Master cone adaptation in the prepared root
canal. (c) Severing of the coronal portion of the master cone with a heated instrument. (d)
Compaction of the master cone. (e) Sequential segments removed with the heat carrier
followed by compaction. (f-h) Once the apical third is reached, the canal is backfilled with
heated segments of gutta-percha followed compaction with suitable pluggers.
44. Advantages
Excellent seal of the canal apically and laterally
Obturation of the larger lateral and accessory canals
Disadvantages
The amount of time it takes
The risk of vertical root fracture resulting from undue force
Periodic overfilling with gutta-percha or sealer
46. Warm Lateral Compaction
This technique provides the advantages inherent to thermo- plastic
techniques as well as length control during obturation.
The technique involves placement of the master cone and lateral
compaction using heat carriers such as Endotec Il tips and EndoTwinn
tips.
The device is placed beside the master cone and activated followed by
placement of an unheated spreader in the space previously occupied by
the heat carrier. Accessory cones are then placed and the process is
repeated until the canal is filled.
47. CONTINUOUS WAVE COMPACTION
TECHNIQUE
Principle
This is a variation of the warm vertical compaction technique
introduced by Buchanan.
The technique employs the use of gutta-percha cones and pluggers that
mimic the tapered preparation, thereby permitting the application of
greater hydraulic force during warm compaction.
48. Clinical Technique
This technique uses tapered nickel-titanium systems to prepare the
canal.
Pluggers are selected in consistence with the size of the shaping
instruments used. Tapered pluggers #.06, #.08, #.10, and #.12 with a tip
diameter similar to the tapered gutta-percha points, respectively, are
employed.
The procedure is carried out with an electric heat carrier system
49. Continuous wave compaction technique. (a) and (b) After selecting an appropriate master cone, a plugger is
prefitted to fit within 5–7 mm of the working length. (c) The System B unit is set to 200°C and the heated
plugger is moved rapidly
(1–2 seconds) to within 3 mm of the binding point. The heat is inactivated while firm pressure is maintained
on the plugger for 5–10 seconds. (d) and (e) After the GP mass has cooled, a 1-second
application of heat separates the plugger from the GP and it is removed. (f)–(i) The remaining canal space
is obturated using a thermoplastic injection technique such as the Obtura III
50. 1. Grossman’s Endodontic Practice – 14TH Edititon
2. Textbook of Endodontics , Nisa garg – 2ND Edition
REFERENCES