Obturating Material

Conservative and endodontic Dentistry

1. 1Department – conservative and
endodontics
Project Topic – Obturating Material

2. Contents

 Introduction
 Objectives of root canal filling
 Criteria for timing of obturation
 Requirements for an ideal root canal filling
material
 Classification of endodontic obturating
material
 Solid core filling material
 Root canal sealers
 Conclusion
 References

3. Introduction
Definition of obturation – Obturation is the method used to fill and seal a cleaned and shaped root
canal using a root canal sealer and core filling material.
- American Association of Endodontists

The three dimensional filling of the entire root canal system as close to the
cementodentinal junction as possible.
- American Dental Association,
Endodontic colleagues, 1994

4. Objectives of root canal filling

 Substitution of an inert filling in the space previously occupied by the
pulp tissue

 To prevent recurrent infection by way of circulation or through a break
in the integrity of the crown of the tooth

 Create a favourable biological environment for the process of
periapical tissue healing

 To obtain fluid tight seal apically and coronally by total obliteration of
the root canal space

 To kill any remaining microorganisms and prevent their growth

5. Clinical criteria for timing of obturation

 Optimal shaping and cleaning of the canal can be easily achieved in
a single sitting in a tooth with vital pulp tissue.

 Extra care and attention should be given while cleaning a canal with
necrotic and infected pulp.

 The canal should be reasonably dry after completion of cleaning and
shaping protocols, with no weeping of fluids in the form of bleeding
or discharge of serous fluids. When seepage into the root canal is
excessive, it can be treated and eliminated by reinstrumentation and
enlarging the canal , and irrigating and sealing it with an intracanal
medicament, such as calcium hydroxide paste.


 Failure of treatment is more common in teeth with pre – existing
periradicular changes. Stringent shaping and cleaning protocols
should be adhered to in such cases before deciding the timing of the
obturation.

 In a multisitting root canal therapy case, care should be taken to
ensure that there is no breakdown or leakage of the temporary filling
material during the obturation visit.

6. 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.


 It should be radio opaque.

 It should not stain the tooth structure.


 It should not irritate the 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. Classification of endodontic obturating material

Types
 Solid core obturating material
 Root canal sealer

12. Solid Core Obturating Materials
Silver points
 Silver points were introduced by Jasper in 1933.
 Silver point is stiffer than gutta percha and can be easily inserted into
a fine tortuous canal.
 No longer recommended for the following reasons –

a. Silver points are rigid and do not adapt to
the internal anatomy of the root canal.
Hence the canal is inadequately obturated.

b. Silver points start corroding when they
come into contact with saliva or
periradicular fluids. The corrosion products
are toxic and lead to the failure of the
endodontically treated teeth.


Silver Points

13. Gutta- Percha
History
 Hill ( 1847 ): developed gutta percha root canal filling known as
“Hill’s stopping”.
 Bowman ( 1867): Demonstrated the use of gutta percha root canal
filling.
 S.S. White Company (1887): Manufacture of gutta percha points.

Composition
 20% : Gutta Percha – matrix
 65% : Zinc Oxide – filler
 10% : Heavy metal sulfates – radioopacifier
 5% : Waxes or resins – plasticizer




Gutta Percha Points

14. Properties
 It does not shrink after insertion unless it is plasticizer with a solvent
or heat.
 It is easily sterilized prior to insertion and does not encourage
bacterial growth.
 It is radioopaque, non staining, and impervious to moisture.
 It can be removed from the root canal easily if necessary.
 It is probably the least toxic and least irritating root canal filling
material.
Chemical Structure
 Trans isomer of polyisoprene .
 Exists in alpha and beta crystalline forms. The material is solid in the
beta phase and does not shrink.
 On heating beta phase changes into alpha phase which is tacky and
flowable under pressure.
 Solid mass alpha phase gutta percha melts at temparature above
65°C and turns into beta phase on slow cooling.

15. Sizes and Tapers
Conventional sizes —
 Extra fine
 Fine
 Medium fine
 Fine medium
 Medium
 Large
 Extra large




Gutta Percha of different sizes

16. Disadvantages of gutta percha
 Lack of rigidity
 Limited shelf life
 Lacks adhesive quality
 Easily displaced by pressure


Advances in Gutta Percha
 Medicated gutta percha( Mgp)
 GP + Chlorhexidine (Activ point)
 GP + Calcium hydroxide ( 40 – 60 %)
 GP + GIC impregnated ( Activ gp )

ISO 2% Taper gutta percha points

17. Mineral Trioxide Aggregate ( MTA)
MTA can be used as a canal obturating material because of its superior
physiochemical and bioactive properties.
Indications
According to Bogen et al., following are the indications for employing MTA
as an obturating material:
 MTA obturation combined with root end resTeeth with open apices.
 Retreatment with MTA obturation
 Internal resorption
 Dens in dente

Composition
MTA is a mechanical mixture of three powder ingredients:
 Portland Cement ( 75%)
 Bismuth Oxide ( 20%)
 Gypsum (5%)
The composition includes :
 Tricalcium Silicate
 Tricalcium Aluminate
 Tricalcium Oxide
 Silicate Oxide
 Bismuth Oxide

19. Resilon
Resilon is a high performance polyurethane introduced as an alternative to
gutta percha.

Composition
 It is a polycaprolactone core material with difunctional methacrylate
resin, bioactive glass, bismuth and barium salts as fillers, and
pigments.

 A resin sealer is always employed with the core filling material for
obturation.

20. Protocol for use
 This system 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.

 Resilon requires 150°C temperature for thermoplasticized techniques
which is less when compared to the 200 ° C temperature required by
normal gutta percha.


 Studies show that Resilon with Epiphany sealer and
thermoplasticized gutta percha with epoxy resin sealer have
comparable sealing ability.

 Tay et al. evaluated the susceptibility of this material to hydrolytic
enzymes and concluded that biodegradation of resilon by bacterial
and salivary enzymes needed further investigation.



Clinical note
Currently, resilon cannot be considered as a replacement for gutta
percha, due to lack of long term clinical outcome studies to demonstrate
the clinical superiority of resilon over gutta percha.

21. Root Canal Sealers
Zinc oxide eugenol based sealers
Most of the sealers in common use contain zinc oxide resin as a base
ingredient of the powder. The liquid usually consists eugenol alone or in
combination with other liquids such as Canada balsam. Included in this
group are the following:
 Grossman’s cement: Roth’s 801 sealer
 Rickert’s sealer: Pulp canal sealer
 Tubli- seal
Grossman’s Cement

Powder Parts
Zinc oxide, reagent 42
Staybellite resin 27
Bismuth subcarbonate 15
Barium sulfate 15
Sodium borate, anhydrous 1
Liquid
Eugenol

22.  Grossman’s cement hardens in approximately 2 hours
at 37° C and 100% relative humidity.
 It’s setting time in a root canal is less. It begins to set in
the root canal within 10 – 30 minutes because of the
moisture present in dentin.
 The setting time is also influenced by the quality of the
zinc oxide and the pH of the resin used, the care and
technique in mixing the cement to its proper
consistency, the amount of humidity in the
atmosphere, and the temparature and dryness of the
mixing slab and spatula.
 Tissue tolerance is satisfactory with little inflammation
and no inhibition of repair

23. Epoxy resin based sealers
 AH 26 is an epoxy resin containing non toxic hardener. Radioopacity
is imparted to it by bismuth oxide. It has strong adhesive properties
and contracts slightly while hardening. However, it was found to
release formaldehyde during setting.
 AH plus is a modified formulation of AH 26 with a working time of
approximately 4 hours and setting time of 8 hours. This sealer does
not release formaldehyde and is currently one of the most
commonly used endodontic root canal sealer.



Composition of AH Plus Epoxy Resin Sealer
Paste A
 Epoxy resin
 Calcium tungstate
 Zirconium oxide
 Silica
 Iron oxide
Paste B
 Adamantaneamine – N
 Calcium tungstate
 Zirconium oxide
 Silica silicone oil

24. Advantages
 Good sealing ability
 Biocompatibility to periapical tissues
 Moderate antimicrobial activity
 Dentinal adhesion
 Long working time and ease of manipulation

Calcium silicate based sealers
Tricalcium silicate is one of the main components of MTA and is now the
focus of newer generation of bioceramic sealers.
Examples :
 Bio root RCS
 Total fill BC sealer

25. Characteristics
 Tricalcium silicate sealers set by reaction with water to form a matrix
of calcium silicate hydrates and calcium hydroxide ( alkaline pH
12).This reaction is followed by the precipitation of calcium
phosphate.
 CSBS have sealing properties comparable to those of epoxy resin
sealers
 They are biocompatible and have the potential to provide a bioactive
surface with stimulation of hard tissue formation.
 They also exhibit antibacterial properties.
 They are recommended to be used along with cold lateral
condensation or single cone obturation techniques.




Clinical Note
 Epoxy resin based sealers along with zinc oxide eugenol based
sealers are the most popular conventionally used endodontic
sealers.
 Calcium silicate based sealers are currently becoming popular due
to their favourable biological characteristics.

26. Conclusion
 As new materials are introduced to fill the root canal system, it is
important to remember Grossman’s tenets and to remember the
proven success of many of the material currently in use.

 With advances in materials and other aspects of endodontics, one
might hope , may promote regeneration of tissues within the tooth
and bone.

References
 Grossman’s Endodontic Practice, 14
th
edition, edited by V. Gopikrishna
 Textbook of Endodontics, Nisha Garg
 Materials used in dentistry, S Mahalaxmi