Introduction History Mechanism of action Antimicrobial effect Tissue dissolving efficacy NaOCl and bioflim Factors affecting Antimicrobial and tissu e dissolving efficacy Haemostatic property Buffered NaOCl Effect of increasing temperature on NaOCl NaOCl and dentin Effect of NaOCl on resin-dentin interface Effect of NaOCl on endodontic instruments Combination of NaOCl with different irrigants Commercially available NaOCl based irrigants Sodium Hypochlorite accidents Hulsman’s criteria Clinical manifestation Management Prevention Conclusion References

1. SODIUM HYPOCHLORITE
Dr Urvashi Sodvadiya

2. Content
Introduction
History
Mechanism of action
Antimicrobial effect
Tissue dissolving efficacy
NaOCl and bioflim
Factors affecting Antimicrobial and tissu
e dissolving efficacy
Haemostatic property
Buffered NaOCl
Effect of increasing temperature on NaOCl
NaOCl and dentin
Effect of NaOCl on resin-dentin interface
Effect of NaOCl on endodontic instruments

3. Content
Combination of NaOCl with different irrigants
Commercially available NaOCl based irrigants
Sodium Hypochlorite accidents
Hulsman’s criteria
Clinical manifestation
Management
Prevention
Conclusion
References

4. Introduction

5. History
1920: was
introduced
in
endodontics
Wide
acceptance:
late 19th
century
To prevent
infectious
diseases:
Labarraque
(1777-1850)
Intially:
NaOCl as
bleaching
agent
Potassium
hypochlorite
: Bethollet
(1748-1822
World war I:
Henry Drysdale
Dakin and Alexis
Carrel
Zehnder M. Root canal irrigants. J Endod 2006 32: 389-398.
Heling I, Rotstein I, Dinur T et al. Bactericidal and cytotoxic effects of sodium hypochlorite and dichloroisocyanurate solutions in vitro. J Endod 2001 27: 278-280
Other Cl-releasing agents
Chloramines-T and Dichloroisocyanurate (NaDCC)1

6. Pecora et al.; 1999
Pecora JD, Sousa-Neto MD, Estrela C. Soluções irrigadoras auxiliares do preparo do canal radicular. In: Endodontia - Princípios biológicos e mecânicos. Estrela C, Figueiredo JAP. Eds.
São Paulo: Artes Médicas; 1999. p 552-569.

7. Antimicrobial
action
NaOCl
OH- ions
Similar to CaOH
Cl- ions
Chloramination
 High pH of NaOCl
 Irreversible bacterial enzymatic inhibition: by
replacing hydrogen with chlorine.
- Reaction of chlorine with amino groups (NH2 - )
- Irreversible oxidation of sulphydryl groups (SH)
of bacterial enzymes (cystein).
 Detoxification of Endotoxin (Buck et al; 2001)

8. Factors
affecting
Anti-microbial
efficacy
Concentration
 Minimum concentration
required: 1%
 No difference in the
antibacterial activity of 1%,
2.5%, and 5% NaOCl (Siqueira et
al; 2000)
In vivo study:
 Necrotic pulp, periapical
lesion: 5.25% (Ercan et al;
2004)
 0.5%: effective after 5th
appotnment (Bystrom and
Sundqvist et al; 1983)
pH
 Inversely proportional
 Greater the initial concentration
of the sodium hypochlorite
solutions, the smaller was the
reduction of its pH

9. Factors
affecting
Anti-microbial
efficacy
Concentration
 4% NaOCl: E faecalis
(Siqueira et al; 1997)
Concentration
of NaOCl
Time required to
kill E faecalis
(Gomes et al; 2001)
0.5% 30 min
1% 20 min
2.5% 1- min
4% 5 min
5.25% < 30 sec
Type of microorganism
 Porphyromonas endodontalis,
Porphyromonas gingivalis, and
Prevotella intermedia in 15s. (Vianna
et al; 2004)
 Antifungal
 Less effective in presence of
smear layer (Sen et al; 1999)
 Time required: 15s to 5min (Smith
etal ;1996, Harrison et al; 1999)
 Superior to Biopure MTAD and
17% EDTA (Ruff et al; 2006)
 Combination:
 NaOCl (5% and 0.5%) and
iodine (2%) potassium iodide
(4%): can kill all yeast cells
within 30s (Waltimo et al; 1999)

10. Depth of penetration
Vahdaty et al. 1993
2% CHX and 2% NaOCl on dentinal tubules infected with E. faecalis.
Significantly reduced the bacterial counts in the first 100 µm of
dentinal tubules, however up to 50% of dentine samples remained
infected following use of both agents

11. NaOCl and
Biofilm Dunavant et al; 2006Radcliffe CE et al; 2004Oncag O et al; 2003
Dunavant TR, Regan JD, Glickman GN et al. Comparative evaluation of endodontic irrigants against Enterococcus faecalis
biofilms. J Endod 2006 32: 527-531.
Radcliffe CE, Potouridou L, Qureshi R, et al. Antimicrobial activity of varying concentrations of sodium hypochlorite on the endodontic microorganisms Actinomyces israelii, A. naeslundii,
Candida albicans and Enterococcus faecalis. Int Endod J 2004;37:438 – 46.
Oncag O, Hosgor M, Hilmioglu S, Zekioglu O, Eronat C, Burhanoglu D. Comparison of antibacterial and toxic effects of various root canal irrigants. Int Endod J 2003;36:423–32.

12. Tissue
dissolution
NaOCl
Fatty acid
degradation
Amino acid
neutralization

13. Factors
affecting tissue
dissolution
efficacy
Concentration
Concentration Time
5% (Grossman and
Meiman; 1941)
20 min to 2 hours
Temperature
 Directly proportional
 How to increase the
temperature clinically?
pH
 Inversely proportional
 Greater the initial concentration
of the sodium hypochlorite
solutions, the smaller was the
reduction of its pH
Time
Quantity (Baker et al)
Spanó JCE, Barbin EL, Santos TC, Guimarães LF, Pécora JD. Solvent action of
sodium hypochlorite on bovine pulp and physico-chemical properties of
resulting liquid. Braz Dent J 2001;12:154-157.

14. Tissue
dissolution:
Vital v/s Non-vital
Clinical conditions: 3% NaOCl- 5 min
Gordon TM, Damato D, Christner P. Solvent effect of various
dilutions of sodium hypochlorite on vital and necrotic tissue.
Journal of endodontics. 1981 Jan 1;7(10):466-9.

15. Haemostatic property of
NaOCl
Since 1950s
3% NaOCl: biocompatible as a heamorrhage
control agent, because pulps treated with this
concentration demonstrated no evidence of
pulpal necrosis after 7- and 27-days.
(Hafez et al.; 2002)
How much concentration is recommended?

16. Increasing The
Temperature Of
Sodium
Hypochlorite
 Collagen-dissolving ability
2.6% sodium hypochlorite was comparable to
that of 5.25% at both 21°C and 37C (Cunningham
and Joseph,1980)
 Antimicrobial effect:
2.6% and 5.25% sodium hypochlorite in
reducing a planktonic
Culture of E coli to below culturable level at
2OC and 37°C: 37 C was more effective.
(Cunningham et al,1980)
 Temperature of sodium hypochlorite to 50 C
did not help in making the root canal
cleaner!

17. Buffered NaOCl
Dakin’s solution: 0.5% sodium hypochlorite buffered with sodium bicarbonate to a pH of 9

18. Long peptide
chains
Fragmentation
and chlorination
of terminal
groups
N-Choramines
(Marending M et al;
2007)
Effect of
NaOCl on
composition
and structure
of dentine
Slutzky-Goldberg I, Maree M, Liberman R et al. Effect of sodium hypochlorite on dentin microhardness. J Endod 2004 30: 880-882.
As a cavity disinfectant: affects only
organic structure of dentin (Mountouris et al.; 2004)
Effects of NaOCl on dentinal structure (Marending et al; 2007)
Concentration-dependent reduction of elastic modulus and
flexural strength in human root dentine
Carbon and nitrogen content: Significantly reduces
No effect on inorganic dentine components
Altered intertubular dentine permeability

19. Buffering effect of Dentine on NaOCl
Enterococcus faecalis A197A
 Organic and inorganic component of
dentine: buffering effect
 Type I collagen and glycosaminoglycan:
lost their immunoreactivity after NaOCl
treatment when a demineralized
dentine model was used. (Oyarzun A et al;
2002)
 Dentine: inhibitory effect on the
antibacterial effectiveness of 1%
sodium hypochlorite (Haapasalo et al; 2000)
Oyarzun A, Cordero AM, Whittle M. Immunohistochemical evaluation of the effects of sodium hypochlorite on dentine collagen and glycosaminoglycans. J Endod
2002 28: 152-156.
Haapasalo HK, Siren EK, Waltimo TM. Inactivation of local root canal medicaments by dentine: an in vitro study. Int Endod J 2000 33: 126-131.

20. Effects of NaOCl on
Resin-Dentin bond
strength
Anti-oxidants
Sodium
Ascorbate
Sodium
Thiosulphate
(Na2S2O3)
Corrêa AC, Cecchin D, de Almeida JF, de Almeida Gomes BP, Zaia AA, Ferraz CC. Sodium thiosulfate for recovery of bond strength to dentin treated with sodium
hypochlorite. Journal of Endodontics. 2016 Feb 1;42(2):284-8.

21. Effects of NaOCl on Endodontic instruments
Pitting and cracks that alter the
integrity of the instrument surface:
decreasing resistance to fracture
because of cyclic fatigue.
Galvanic corrosion may occur.
Berutti and Marini; 1996
Significant corrosive phenomena of
NiTi instruments exposed to 1%
NaOCl for up to 10 cleaning cycles.
No significant reduction of torque at
fracture or number of revolutions to
flexural fatigue
O’Hoy et al; 2003
Mechanical properties of Ni-Ti
instruments: not affected by NaOCl,
nor was the cutting efficiency.
Haikel et al; 1998

22. NaOCl and EDTA
 Effect of Final flush using NaOCl after application of EDTA
Removal of organic substance of dentin (Marshal GW, 2001)
 Duration:
1 min, 3 min and 5 min: no significant difference (Niu et al; 2002)
 Which should be the last irrigant?

23. NaOCl and CHX
 Why do we need to combine these two irrigants?
 2% CHX + 1% and 5.25% NaOCl: Orange brown precipitates (Saquy PC; 1994)
 Para-chloroaniline (PCA): mutagenic and cytotoxic (Chhabra et al; 1991)
 Blockade of dentinal tubules: middle and apical third (Bui TB et al; 2008)
 ALX + NaOCl: more effective as a combination, does not form PCA (Kim et al; 2012)

24. Sodium Hypochlorite versus CHX
Gomes et al; 2001

25. NaOCl and Citric acid
 Why do we need to combine these two irrigants?
 10% CA + 1% NaOCl: pH between 1.8 and 4.3, Cl decreases immediately (Zehnder et
al; 2005)
 CA + NaOCl: more chlorine may be detectable and also present at further distance
compared to adding EDTA (Baumgartner and Ibay ;1987)

26. NaOCl and Maleic acid
 Why do we need to combine these two irrigants?
 7% MA: more effective than 17% EDTA (Prabhu SG et al; 2003)
 Combination: significantly reduces available Chlorine

27. Interaction
between
NaOCl and MTA
 According to [68], White MTA and bismuth
oxide in NaOCl may result in dark
discoloration (Camilleri; 2014)
 5% NaOCl significantly reduces the surface
roughness of Portland cement. (Ballester-
Palacios et al.; 2013)
 NaOCl + MTA: improved the handling
properties and decreased setting time. (Al-
Anezi et al; 2011)
SYNERGISM BETWEEN Calcium Hydroxide
(Ca(OH)2 ) AND NaOCl

28. Chlor-Extra
 5.85% NaOCl and a detergent
 Wetting ability: 2.5 times more
than regular NaOCl (Wang Z et al;
2012)
 Actinomyces israelii (Mohammadi et
al.; 2002)
Chlor-XTRA >> NaOCl, CHX,
Tetraclean and Hypoclean
 More tissue dissolving ability than
regular NAOCl (Stojicic et al;
2010)

29. Hypoclean
• Introduced by Giardino
• 5.25% sodium hypochlorite and
two different surfactant agents:
cetrimide and polypropylene
glycol.
• C. albicans, P. aeroginosa, and L.
casei (Mohammadi et al.; 2002)
• Hypoclean >> NaOCl, CHX,
Tetraclean and Chlor-extra

30. Sodium hypochlorite accidents
Damage to clothes
Damage to the eyes
Damage to the Skin
Damage to the Oral mucosa

31. Acute pain, swelling, and redness
Bruising
Progressive swelling involving the infraorbital area or mouth angle
depending on the site of NaOCl injection
Profuse hemorrhage often manifesting intraorally from the orifice of the
tooth
Numbness or weakness of the facial nerve
Secondary infection, sinusitis, and cellulitis
Hulsmann's criteria
Complications during root canal irrigation--literature review and case reports. Hülsmann M, Hahn W Int Endod J. 2000 May; 33(3):186-93.

32. Clinical manifestation
Guivarc'h M, Ordioni U, Ahmed HM, Cohen S, Catherine JH, Bukiet F. Sodium hypochlorite accident: a systematic review. Journal of
endodontics. 2017 Jan 1;43(1):16-24.

33. Preoperative After 30 days of treatment

34. Proposed templet to record data after sodium hypochlorite extrusion

35. Management
Early recognition
Time
Immediate
irrigation
Local and oral
analgesics
Cold and heat
pack
Steroids Antibiotics
Local
Anaesthesia
Su-Hsin W, Ming-Pang C, Jen-Chan C, Chih-Ping C, Yi-Shing S. Sodium hypochlorite accidentally extruded beyond the apical
foramen. J Med Sci. 2010;30:61–5
Healing phase

36. Prevention
Radiograph
Rubber dam
application
Protective eye wears
Placement of
irrigation needles 1-3
mm short of apex
(Chaugule VB et al; 2015)
Luer lock side-
venting needles

37. Amount
• Pulp dissoving efficacy: 5% and 2.5%, but not of 0.5% NaOCl
5% and 2,5%: 3 ml – excessive amount (Koskinen et al.; 1980)
• Effectiveness of lower concentrations can be improved by using larger volumes of
irrigant, replenishing the irrigant frequently and increasing the contact periods
Most common answer: 5-10 ml, Duration: less than a minute

38. Concentration
&
Duration
Surface area of the canal
Amount of organic matter
Concentration of solution

39. Conclusion

40. References
• Marending M, Luder UH, Brunner TJ et al. Effect of sodium hypochlorite on human root dentine –
mechanical, chemical and structural evaluation. Int Endod J 2007 40: 786-793.
• Slutzky-Goldberg I, Maree M, Liberman R et al. Effect of sodium hypochlorite on dentin microhardness. J
Endod 2004 30: 880-882.
• Mountouris G, Silikas N, Eliades G. Effect of sodium hypochlorite treatment on the molecular composition
and morphology of human coronal dentin. J Adhes Dent 2004 6: 175-182.
• Hafez AA, Cox CF, Tarim B et al. An in vivo evaluation of hemorrhage control using sodium hypochlorite
and direct capping with a one- or two-component adhesive system in exposed nonhuman primate pulps.
Quintessence Int 2002 33: 261-272.
Marshall GW. Yucel N. Balooch M. Kinney JH. Habelitz 5. Marshall SJ. Sodium hypochlorite alterations of
dentine and dentine collagen. Surface Science 200 I ; 49 I :444 -55.

41. References
• Mohammadi Z. Strategies to manage permanent non-vital teeth with open apices: A clinical update. Int Dent J 2011;
61(1): 25-30.
• Roberts HW, Toth JM, Berzins DW, Charlton DG. Mineral trioxide aggregate material use in endodontic treatment:
A review of the literature. Dent Mater 2008; 24(2): 149-64.
• Torabinejad M, Chivian N. Clinical applications of mineral trioxide aggregate. J Endod 1999; 25(3): 197-205.
• Zapf AM, Chedella SC, Berzins DW. Effect of additives on mineral trioxide aggregate setting reaction product
formation. J Endod 2015; 41(1): 88-91.
• Camilleri J. Color stability of white mineral trioxide aggregate in contact with hypochlorite solution. J Endod 2014;
40(3): 436-40
• Ballester-Palacios ML, Berástegui-Jimeno EM, Parellada-Esquius N, Canalda-Sahli C. Interferometric microscopy
study of the surface roughness of Portland cement under the action of different irrigants. Med Oral Patol Oral Cir Bucal
2013; 18(5): e817-21
• AlAnezi AZ, Zhu Q, Wang YH, Safavi KE, Jiang J. Effect of selected accelerants on setting time and
biocompatibility of mineral trioxide aggregate (MTA). Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;
111(1): 122-7.

42. Thank you!