EFFICIENCY OF DIFFERENT CONCENTRATION OF SODIUM HYPOCHLORITE DURING ENDODONTIC TREATMENT

JEFFERSON J.C MARION

FREDERICO CAMPOS MANHAES

HOMERO BAJO

THAIS MAGESTE DUQUE

Dental press endod.2012 0ct –dec 2(4)32-7

INTRODUCTION Root Canal therapy :Involves removing the diseased or dead pulp and

replacing it with a substance that will help prevent any re-infection.

STEPS FOLLOWED FOR ROOT CANAL TREATMENT

Examination and diagnosisPlanning of procedureMaking access cavityCleaning and shaping of canalsFilling of canalsFinishing of root canal

STEPS FOLLOWED FOR ROOT CANAL TREATMENT

INTRODUCTION Successful root canal therapy relies on the

combination of1. Proper instrumentation,2. Irrigation, 3. Obturation of the root canal. Of these three essential steps irrigation of the root canal is the most

important determinant in the healing of the periapical tissues

(J Conserv Dent.

2010 Oct-Dec; 13(4): 256–264)

INTRODUCTION Infection of root canals are mixed,

predominately gram negative anaerobic bacteria.

Antimicrobial agents must suppress or destroy microbial growth ; thus

Susceptibility of micro organism Penetration to infected site Adequate concentration Low toxicity to host cell

( BRAZ DENT J 13(2) 2002)

INTRODUCTION The process of reducing or eliminating the

micro biota of infected root canals with apical periodontitis begun during root canal preparation with chemical agents

The use of intra canal dressing aids in success of this process.

INTRODUCTION The use of chemical substance in order to reduce or

eliminate bacteria has always been present in endodontics.

The chemical means (auxiliary chemicals substances) and physical means (irrigation and aspiration )form single and simultaneous process which is the chemo-mechanical preparation of root canal

IDEAL REQUIREMENTS OF ROOT CANAL IRRIGANTS

Broad antimicrobial spectrum High efficacy against anaerobic and facultative

microorganisms organized in biofilms Ability to dissolve necrotic pulp tissue remnants Ability to inactivate endotoxin Ability to prevent the formation of a smear layer during

instrumentation or to dissolve the latter once it has formed.

Systemically nontoxic when they come in contact with vital tissues, noncaustic to periodontal tissues, and with little potential to cause an anaphylactic reaction

(J Conserv Dent. 2010

Oct-Dec; 13(4): 256–264)

ENDODONTIC IRRIGANTS

CHEMICAL AGENTS NATURAL AGENTS

TISSUE DISSOLVING AGENT

(Eg; NaOCl ,ClO2

ANTIBACTERIAL AGENT

1. Bactericidal (eg CHX)2. Bacteriostatic( eg; MTAD)

CHELATING AGENT MILD pH (HEBP)

ANTIBACTERIAL AGENT

( eg; green tea ,triphala)

J Conserv Dent. 2010 Oct-Dec; 13(4): 256–264

STRONG pH (EDTA)

HISTORY

Sodium Hypochlorite (NaOCl) has an extensive history in medicine and dentistry and continues to be popular even today. During World War I, the chemist Henry Drysdale Dakin and the surgeon Alexis Carrel extended the use of buffered 0.5% NaOCl solution to the irrigation of infected wounds

Thus sodium hypochlorite chosen as an endodontic irrigating solution for use by most of professionals.

MECHANISM OF ACTION OF SODIUM HYPOCHLORITE

SAPONIFICATION REACTION O O ║ ║ R-C-O-R + NaOH R-C-O-Na + R-OHFatty acid sodium soap glycerol hydroxide

So the dissolution of organic necrotic tissue can be verified in saponification reaction when NaOCl degrades fatty acid and lipid resulting in soap and glycerol and promoting as deodorant effect. (BRAZ DENT J 13 (2) 2002)

AMINO ACID NEUTRALIZATION REACTION

H O H O Ι ∕ ∕ Ι ∕ ∕ R-C-O-C + NaOH R-C-O-C + H20 Ι Ι NH2 NH2 Amino sodium salt water Acid hydroxide

With exit of hydroxyl ions reduction of pH.

CHLORAMINATION REACTION

H O Cl O Ι ∕ ∕ Ι ∕ ∕R-C-O-C + HOCl R-C-O-C + H20 Ι OH Ι NH2 NH2 OHAmino hypochlorous chloramine water Acid acid

Hypochlorous acid (HOCl) hypochlorite ion lead to amino acid degradation and hydrolysis.

CHLORAMINATION REACTION

According to Estrela et al, NaOCl neutralize the amino acids forming water and salt.

The Hypochlorous acid a substance present in the NaOCl solution.

When in contact with organic tissue act as a solvent releasing chlorine –combined with amino group of proteins form chloramines.

Hypochlorous acid and hypochlorite ion lead to degradation of amino acids and hydrolysis.

WHY SODIUM HYPOCHLORITE USE AS IRRIGANT?

PROPERTIES Dissolving organic tissueAntimicrobial actionAlkaline pHPromote whiteningDeodorizingLow superficial tension

COMPLICATIONS DAMAGE TO CLOTHES sodium hypochlorite is a common household

bleaching agent, even small amounts may cause severe damage.

When using an ultrasonic device for root canal irrigation the aerosol may also cause damage.

COMPLICATIONS DAMAGE TO EYES Irritant in contact with the patient’s or

operator’s eyes results in immediate pain, profuse watering, intense burning, and erythematic.

Loss of epithelial cells in the outer layer of the cornea may occur.

COMPLICATIONS EFFECT ON PERIODONTAL TISSUE They also say that the highest concentration

shows more irritating effect on periodontal ligament.

The leakage of this material during endodontic treatment may cause sequelae such as

1. pain 2. Swelling3. bruising 4. numbness

Symptomatology Immediate severe pain Immediate edema of neighboring soft tissues Possible extension of edema over the injured half side of

the face, upper lip, infraorbital region Profuse bleeding from the root canal Profuse interstitial bleeding with hemorrhage of the skin

and mucosa (ecchymosis) Chlorine taste and irritation of the throat after injection

into the maxillary sinus Secondary infection possible Reversible anesthesia or par aesthesia possible

SODIUM HYPOCHLORITE

WALKER was the first researcher to think of NaOCl as irrigant .

According to SPANGBERG, ENGSTROM ,LANGELAND the use of sodium hypochlorite at high concentrations has been recommended to degrade protein products present in root canal.

However high concentration damage periapical tissue.

SODIUM HYPOCHLORITE According to Estrela et al, several irrigating

solutions have been proposed to help in root canal preparation .

Nevertheless, according to these authors ,an effective solution is crucial to sanitization process because

Favors the cleaning Preparation Neutralization of septic necrotic content

SODIUM HYPOCHLORITE In reviewing the microbial efficacy of NaOCl it

seems similar to calcium hydroxide because High ph of NaOCl Interferes integrity of bacterial membrane Cellular metabolism Degradation of phospholipids

The NaOCl became most popular agent for endodontic irrigation although its ideal concentration is not an universal consensus.

AIM OF STUDY Literature review was conduct in order to

verify which NaOCl concentration is most efficient in controlling micro organism during endodontic treatment.

LITERATURE REVIEW

The root canal cleaning not only depends on:

the mechanical action of instruments, on the action of irrigating solutions that

lubricate this canal during cutting action of endodontic instruments .

help in removing smear layer have germicidal potential solvent action on exudate and pre dentin

ABILITY TO DISSOLVE ORGANIC TISSUE

The ability of NaOCl to dissolve organic tissue is directly proportional to its concentration.

According to Baumgartner ad, cuenin , efficacy of solvent and disinfectant action of NaOCl solutions at low concentration can be increased by using higher volume of solution and frequent exchanges.

FACHIN , HAHN, PALMINI STUDY

Use of NaOCl solutions in endodontics , analyzing aspects such as

Optimal concentration Solvent action Tissue reaction Bactericidal effect Capability of removing organic debris They observed that at higher concentration the

dissolution of organic tissue is increased.

Rev Bras endod.1994,51(6):14-8

SPANO ET AL STUDY the solvent effect , Residual level of chlorine Ph Surface tension Before and after dissolution of tissue of four

concentration of NaOCl ( 0.5 %, 1.0%, 2.5%, 5.0%) on bovine pulp tissue.

The higher concentration of NaOCl were more rapid on dissolution of pulp tissue ,and showed lower decrease in chlorine concentration.

Braz Dent J. 2001; 12(3): 154-7

OKINO ET AL STUDY

evaluated the solvent activity of various irrigants on bovine pulp tissue. The tested solutions were 0.5%, 1.0% and 2.5% NaOCl; 2% chlorhexidine gluconate solution and 2% chlorhexidine gel

Results1.Chlorhexidine preparations were not able to dissolve the pulp

tissue.

2.All NaOCl solutions were effective in dissolving pulp tissue and the dissolution rate varied with the solution concentration.

..

Int Endod J. 2004;37(1); 38-41

EFFECTIVE ANTIMICROBIAL ACTION

Siquiera et al, studied the antibacterial effect of endodontic irrigants in anaerobic gram negative bacteria and facultative bacteria.

Solutions used were 0.5%, 2.5%, and 4.0 % NaOCl ;0.2% and 2% chlorhexidine ;10.0% citric acid and 17% EDTA

RESULTAll solutions inhibited the tested bacteria.1.The 4.0% NaOCl proved to be most effective

antibacterial agent.2.Both 0.2% and 2.0% chlorhexidine solution

inhibited all bacteria but were less effective than 2.5% and 4.0% NaOCl

Dametto et al study evaluated in vitro the anti microbial activity of

2% chlorhexidine gel against the enterococcus faecalis compared with 2% chlorhexidine liquid and 5.25 % NaOCl .

Authors observed that the 2% chlorhexidine gel, chlorhexidine liquid and 5.25% NaOCl

However NaOCl was not able to maintain this reduction after 7 days.

The result show again the residual effect provided by the chlorhexidine.

Oral Surg Oral Med Oral pathol oral radiol endod,2005 ;99(6);768-72

RAPHAEL ET AL STUDY performed an vitro study of antibacterial efficiency of 5.25%

NaOCl used at different temperature. Extracted human teeth used which were

sterilized ,instrumented and inoculated with enterococcus faecalis ,pseudomonas aeruginosa or staphylococcus aureus.

The root canal were irrigated with NaOCl at temperature from 21˚c to 31˚c and 0.9% saline solution was used as control.

Result showed that there is no direct relation between the NaOCl

temperature and its antimicrobial action ,the increase in temperature did not provide difference in the number of negative cultures.

JEndod.1981;7(7);330-4

ALKALINE PH Pecora, proposes a NaOCl solution with 0.5% to

0.6% of active chlorine per 100 ml with boric acid to reduce the ph, decreasing ph solution near to neutral.

Addition of boric acid decrease the ph and provides less NaOCl reducing the irritant effect of NaOCl .

The author stresses the fact that the proposed solution is unstable ,should not be stored for too long ,must be packed in amber glass and kept in cool place with no incident light.

The NaOCl with higher ph is more stable and presents slower chlorine release .

When ph is reduced the solution become very unstable and the chlorine release is faster resulting in lower life cycle

MALTHA AND PLASSCHAERT STUDY

The alkaline content of NaOCl is proportional to its concentration.

In other word the higher the concentration ,higher the ph.

Since its has greater amount of NaOH molecules . the high ph of these solutions is not a

disadvantage ,since their action is limited to surface of the tissue; it may even represent a positive action because by being alkaline ,this ph neutralizes the medium acidity making it appropriate for bacterial growth.

DEODORANT ACTION

According to Gomes , Drucker, and liley, infections caused by anaerobic bacteria often produce strong odor due to production of short chain fatty acids, sulfur compounds ,ammonia and polaminas.

Chlorine through its lethal activity on micro organism and oxidative action on dead tissue and bacterial products, eliminate the fetid odor produced by necrosis.

LOWER SURFACE TENSION NaOCl solution its surface tension which is similar to

the water and some how prevents initimate contact of this liquid with the dentin .

Lopes siqueira jr. and Elias defined the surface tension as a intrinsic characteristic of each liquid varying with temperature and the type of surface contacted.

Suggested there is a greater interaction of hypochlorous acid with organic matter and is more concentrated solution there is a greater interaction of sodium hydroxide with organic matter leading to greater surface tension reduction in NaOCl solutions with higher concentration

SPANO ET AL STUDY higher the initial concentration of NaOCl solution

the greater is reduction in surface tension on final solution .

Explained by the fact that the solutions with higher active chlorine concentration and therefore higher sodium hydroxide concentration provide greater formation of fatty acids salts .

CYTOTOXICITY

Noleto et al evaluated in vivo the irritating potential of different NaOCl concentration used in root canals irrigation.

Were tested the 1.0% ,2.5%,and 4.8% concentration .

Authors concluded that the evaluated NaOCl solution promoted irritation with variable intensity depending directly on the concentration used.

MEHDIPUR ET AL AND SILVA ET AL STUDY

reported that the severity of NaOCl cytotoxicity depends on1. the solution concentration2. ph 3. duration of tissue exposure to agent . They also say that the highest concentration shows more

irritating effect on effect on periodontal ligament. The leakage of this material during endodontic treatment may

cause sequelae such as1. pain 2. Swelling3. bruising 4. numbness 5. ,compatible with a chemical burn.

Compend Contin Educ Dent .2007;28(10);544-50

DISCUSSION As presented by Cunningham , Balakejian:

Spano et al ,Beltz, Torabinejad, Naenni, Thoma, Zehnder the NaOCl ability to dissolve organic tissue is directly related to its concentration.

This statement confirm Baumgartner and Cuenin study ,which observed that the higher the concentration the more rapid the tissue dissolution.

Fachin ,Hahn and Palmini affirmed that the 0.5% NaOCl concentration is more biocompatible but less stable

DISCUSSION According to borin ,melo ,oliveira ,the 1%

NaOCl concentration is most used and studied and its great action on organic tissue by dissolving 0.43 mg per minute .

Examining 1% NaOCl ,Radcliff et al reported that the time needed to inhibit all enterococcus faecalis strain is 10 min .

DISCUSSION Fachin ,Hahn, Palmini reported that the

1%NaOCl has stabilizers which makes it use more viable to long term because this stabilizer gives greater shelf life provided it is refrigerated and stored in amber bottle.

DISCUSSION 2.5% NaOCl proved to be better solution than

and others because it has greater effectiveness than 0.5% and 1% con centration and has lower cytotoxicity than 5.2% concentration .

The 2.5% NaOCl is capable to inhibit 100% of the enterococcus faecalis in 5 min eliminating pain of patient with endo dontic urgency with faster inhibition of bacteria and shorter time for root canal sanitization

DISCUSSION Regarding organic tissue dissolution and bacteria

inhibition ,a 5.25 % NaOCl solution is more effective in shorter time because its high concentration of hypochlorite acid in contact with organic tissue leads amino acids degradation and hydrolysis promoting the death of the root canal bacteria within 2 min .

Nevertheless in cases of extravasations --- the 5.25 % NaOCl can due to its high cytotoxicity can cause sequelae such as

Pain Swelling Bruising Numbness

Conclusion 1. Based on this literature review it is clear that all

NaOCl concentration mentioned in this paper have limitation as well as clinical indication therefore research on new substances in order to find an ideal irrigant for endodontic treatment should be performed.

2. According to this study it was observed that 5.25% NaOCl has better effectiveness in dissolving organic tissue, greater antibacterial action,more alkaline pH.

3. In contrast is more irritating to periapical tissue making its use undesirable .

4. Both 2.5%naocl and 5.25% NaOCl have similar properties but the first on is less cytotoxic being more indicated for root canals endodontic treatment.

REFERENCES Dental press endod.2012 0ct –dec 2(4)32-7 J Conserv Dent. 2010 Oct-Dec; 13(4): 256–

264 BRAZ DENT J 13(2) 2002 Rev Bras endod.1994,51(6):14-8 Int Endod J. 2004;37(1); 38-41 Oral Surg Oral Med Oral pathol oral radiol

endod,2005 ;99(6);768-72