Medical

Communication

Biosci. Biotech. Res. Comm. 10(2): 40-48 (2017)

Evaluation of tissue dissolution ability of modi ed

chlorhexidine as a root canal irrigant

Samira Shahsiah

, Arash Azizi

*, Eskandar Moghimipour

, Paul V. Abbott

Kasra Karamifar

, Mansour Jafarzadeh

and Mina Fazeli

Department of Endodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

Oral medicine Department, Islamic Azad University,Dental Branch, Tehran, Iran

Medicinal Plant Research Center,Faculty of Pharmacy,Ahvaz Jundishapur University of Medical Sciences,

Ahvaz, Iran

Winthrop Professor of Clinical Dentistry,University of Western Australia, Australia

Department of Endodontics, Dental Branch, Shiraz Islamic Azad University, Shiraz, Iran

Department of Endodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

Dentist

ABSTRACT

The  rst and main goal of root canal treatment is the elimination of microorganisms from the contaminated root canal system

and providing an environment for the healing of periapical tissues. Instrumentation alone cannoteffectivelyclean the complex

root canal system. Souse of irrigantsalong mechanicalpreparationis required. But no single solution is able to ful ll these actions

completely. Chlorhexidineis one of the substances thatis usedas anirrigantin endodontics. It has broadantimicrobialspectrum, but

itdoes not have theability todissolveorganictissues. It has been shownthat theaddition ofsurfactantin thesolution can increasesthe

abilityof dissolvetissue.In this in vitro study tissue-dissolving capacity of sodium hypochlorite (5/25% and 2/5%), chlorhexidine

(0/2%) and modi ed chlorhexidine (chlorhexidine + benzalkonium chloride and chlorhexidine + sodium lauryl solphate) were

compared.Tissue samples prepared from bovine pulp and each of the samples immersed for 20 minutes in each test solution

(changing the solution every 2 minutes).The sampleswereweighedbefore and aftertesting. The weight difference divided by the

initial weight of the tissue sample, multiplied by 100, was de ned as the percentage of tissue solubility.NaOCl 5/25% was more

solublethantheothersolutions. ExceptCHX 0/2% and salineno statistically signi cant differences was found between the tissue-

dissolving properties of othersolutions and NaOCl 5/25%.The results of this study indicate that the use of 0/2%CHX+2%SLS as

irrigant in endodontic can show similar effect with NaOCl 5/25% in the solubility.

KEY WORDS: ROOT CANAL THERAPY, CHLORHEXIDINE, TISSUE SOLABILITY, BENZALKONIUM CHLORIDE, SODIUM LAURYL SULPHATE

ARTICLE INFORMATION:

*Corresponding Author: drarashazizi@yahoo.com

Received 12

April, 2017

Accepted after revision 30

June, 2017

BBRC Print ISSN: 0974-6455

Online ISSN: 2321-4007 CODEN: USA BBRCBA

Thomson Reuters ISI ESC and Crossref Indexed Journal

NAAS Journal Score 2017: 4.31 Cosmos IF : 4.006

reserved.

Online Contents Available at: http//www.bbrc.in/

Samira Shahsiah et al.

INTRODUCTION

Studies illustrated that different methods of using tools

during cleaning and forming produces smear layer

which covers dentinaltubule canal and inlet (Johnson

W.T , et al, 2008; Belts R.E , et al, 2003). This layer diam-

eter is mμ2- and it is disordered and formless (Karale R

, et al, 2011). From Pulp organic ingredients and inor-

ganic dentin debri, micro-organisms, their products and

necrotic are formed (Johnson W.T , et al, 2008; Karale R ,

et al, 2011; Baumgartner J.C , et al, 2007; Belts R.E , et al,

2003). Smear layer presence avoids penetration of medi-

cine in canal into root canal system and dentinal tubules

and also prevents full compatibility of  lling materials

with surface of canal prepared walls (Belts et al, 2003).

Different acids, ultra sonic tools, and lasers are used

for removing this layer (Belts et al, 2003). One material is

Ethylene diaminete traacetic acid (EDTA). This chemical

is part of chelatorthat has capacity of removing inor-

ganic elements however cannot remove inorganic mate-

rials. So there is need to use a tissue solvent material

such as NaOCl. Recommended time for removing smear

layer by EDTA is 1 minute. This material will cause pre-

tubular and intratubular exceeding omission (Johnson et

al, 2008). Generally, detergents are categorized as follow

(Kandaswamy and Venkateshbabu 2010):

Sodium hypochlorite (NaOCl) with density of 5/0–

25/5% is the most prevalent detergent which is used for

endodontic treatments (Karale et al, 2011; Guerreiro-

Tanomaru 2011). NaOCl has different advantages includ-

ing mechanical cleaning of debris of canal, capacity of

solving alive tissues and necrotic, anti-microbial activ-

ity, blundering activity and long shelf-life. In addition,

this cheap material is highly accessible (Johnson et al,

2008; Karale et al, 2011; Guerreiro-Tanomaru 2011).

Popular density of NaOCl is 5/2%in which tissue solu-

bility and anti-microbial characteristics are maintained.

This density normally is used in teeth with necrotic pulp

or apical priodentit (Johnson et al, 2008; Guerreiro-

Tanomaru 2011).

NaOCl averagely is effective against bacteria but

it has less effect against endotoxin in infected canals

(Kandaswamy and Venkateshbabu 2010). It has also

some restrictions in solving tissues due to limited con-

tact with existing tissues in whole canal space (Johnson

et al, 2008).Unfortunately using NaOCl has some disad-

vantage. This material is very toxic and creates severe

in ammatory reaction in addition when it crosses the

root apex accidentally; it produces severe pain, swelling

and hematoma (Karale et al, 2011).

Chlorhexidine gluconate (CHX) is a mouth wash that

is used in different densities as a detergent for endo-

dontic treatment. CHX is a broad extent anti-microbial

factor against gram-positive bacteria and gram-negative

bacteria. This material has low toxic property and it is

absorbed by dental tissue and mucousmembrane, while

its effective material is released slowly. Biocompatibility

property and substantivity of CHX justi es clinical use

of this material (Kandaswamy and Venkateshbabu 2010;

Karale 2011; Guerreiro-Tanomaru 2011). Anti-microbial

property of 2% CHX is similar to NaOCl 25/5% while

enterococcus faecalis is more effective (Johnson et al,

2008). One disadvantage of Chlorhexidine gluconate is

lack of ability for solving necrotic tissue and remov-

ing smear-layer (Johnson et al, 2008; Kandaswamy and

Venkateshbabu 2010) which may has effect on other

properties of this material (Guerreiro-Tanomaru J.M,

2011).

Out of different materials, surfactant had accept-

able solubility, because it has either Hydro philic or

hydrophobe properties. This material is solved in hydro

phase through hydrophilic property and it is solved via

hydrophobo in organic phase and cause solution of

present material in both phases. In addition, this mate-

FIGURE 1. Endodontic detergents

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EVALUATION OF TISSUE DISSOLUTION ABILITY OF MODIFIED CHLORHEXIDINE 41

Samira Shahsiah et al.

rial decreases surface tension of bacteria cell walls so

it destroys them via which it implements anti-bacterial

properties (Aulton and Taylor 2008).

According to disadvantage of NaOCl including toxic-

ity and providing sever in ammatory reactions (Karale

et al, 2011 ) and based on advantages of CHX including

broad antimicrobial property, informality and biocom-

patibility, using CHX as detergent is more appropriate

in endodontic treatment. However lack of ability of this

material in solubility of remained tissues has caused

limitation of its application. So adding one material

with tissue solubility properties into CHX can handle

this problem and it can provide a detergent with better

properties.

Irrigation of root canal during root treatment is an

important phase. There is no evidence that approved

detergent type role in success of the treatment. So there

is no agreement on what detergent is the best one or on

what detergents are better if they are both used. How-

ever they all agree that the detergent need to have anti-

microbial activity. The best result is obtained from using

a good detergent with anti-bacterial activity when it

contacts long enough with batteries of root canal system.

This means that, for ful lling preparation stage before

obtuaration, detergent needs to be reached a suf cient

volume during the treatment (Iqbal 2012). It seems that

using local medicine is more effective and better that all

applicable antibiotic plans (Martin 1991).

Irala et al (2010) in Luterana University in Brazil per-

formed studies on different densities on NaOCl alone

and also with combination of EDTA. Results indicated

that combination of NaOCl with EDTA has no ability of

tissue solution. T-test also indicated that 2/5% NaOCl

solve the tissue in less time than 1% NaOCl. On the

other hand, solutions’ PH were decreased in 48 hours. In

addition, Cobankara et al in 2010 in Secuk univesristy

of Turkey performed an experiment on Cobankara and

chlorine dioxide. Studies illustrated that saline has no

capacity of solving organic tissue. Both 25/5% NaOCl

and 8/13%ClO

solution more effectively solved pulp tis-

sue in compare to control saline (P<0/05). On the other

hand, no statistical difference between solubility capac-

ity of 25/5% NaOCl and 8/13%ClO

was observed. It was

indicated that both materials have similar effect con-

sidering tissue solubility. In addition, Cbristensen et al

(2008) in Alabama Birmingham University investigated

effect of sodium hypochlorite PH decrease on its tis-

sue solubility property. Statistical results did not show

signi cant difference in groups with PH 12 and PH9.

While there was signi cant difference in groups with PH

12 and PH 9 and group with PH6. Higher densities and

longer durations caused increase of solubility.

In this study two surfactantincluding 4% Benzalko-

nium and 2% Sodium lauryl Sulfate have been studied.

General objective is study of tissue solubility of changed

chlorhexidinein root cleaning. We aimed at answering

following questions:

– How much is the weight loss percentage of pulp

tissue after using 5.25%NaOCl solution?

– How much is the weight loss percentage of pulp

tissue after using 2.5%NaOCl solution?

– How much is the weight loss percentage of pulp

tissue after using 0.2% CHX solution?

– How much is the weight loss percentage of pulp

tissue after using CHX + Benzalkonium chloride

solution?

– How much is the weight loss percentage of pulp

tissue after using CHX + Sodium lauryl sulfate

solution?

– Are weight loss percentages of pulp tissue differ-

ent in experimental groups?

At the following we explained materials and methods

of collecting data and collecting samples. In section 3

we provided research results and statistical tests. After

discussing the cases we provided  nal conclusion.

MATERIALS AND METHODS

In this study, in order to providing pulp samples, we used

bovine mandible of one-year-old calf from slaughter-

house. Milkanseizure teeth were separated from mandi-

ble. There was germ on permanent anseizure tooth under

these teeth which was accessible by mandible bone

cleavage. Teeth pulp covered with thin skin of enamel

was separated and It was kept in 40-c degree in central

laboratory of Pharmacy department until experiment’s

time. Solutions of the experiment were prepared by an

expert from laboratory of Pharmacy department who

had no interference in. and he coded them from number

1 to 6. The tester had no information of group codes

and solution types. Solution lists are as follow:NaOCl

25/5%,NaOCl 5/2%,benzalkonium chloride 4% CHX

+2/0%, sodium lauryl sulfate2% CHX +2/0%, CHX

2/0%,NaCl9/0% as a controller

During experiment, pulp samples were divided into

sections with weight approximate to 25mg. samples were

categorized in 5 groups with 10 samples and one group

with 5 samples as control group.Each sample weight

was measured with digital scale before experiment.

Sample was transferred to experiment tube and tube

were coded. After preparation of samples, 2ml experi-

ment solution was poured on pulp sample in experiment

tube by syringe. And sample was place on vibrator for 2

minutes. After 2 minutes the solution was extracted by

syringe from experiment tube. Then 2ml fresh solution

was added to the sample and it was placed on vibrator

for another two minutes. This process was performed for

42 EVALUATION OF TISSUE DISSOLUTION ABILITY OF MODIFIED CHLORHEXIDINE BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

Samira Shahsiah et al.

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EVALUATION OF TISSUE DISSOLUTION ABILITY OF MODIFIED CHLORHEXIDINE 43

10 times for each sample. By this method, each sample

had contact with fresh solution for 20 minutes. After 20

minutes, all solution was extracted by syringe from the

tube and pulp sample was dried. Finally, weight of dry

pulp sample was measured by the same digital scale and

it was recorded.

This method was performed for each 6 group and

the results were recorder. For calculating percentage of

weight loss, weight difference of tissue sample before

and after contact with solution under experiment was

divided into initial weight of tissue and was multiplied

in 100 (Zehnder M, 2006; Siqueira J.F, et al, 2009). In

order to test obtain results, data summary was reported

for average and standard deviation of X±SD and in

order to comparing groups we used one-way analysis

and then we used post hoc for pairwise.

Based on before studies, there would be 10 samples

in each group with 25ml weight (Kleier et al, 2008). In

this study, 6 groups of solution were experimented. Tis-

sue samples were washed with solutions. For calculat-

ing percentage of weight loss, weight difference of tis-

sue sample before and after contact with solution under

experiment was divided into initial weight of tissue and

was multiplied in 100. Results are in table (1).

In addition, diagrams (1) to (6) represent percentage

of tissue solubility in samples of group 1 to 6. Solu-

tion with code number 1 which included 25/5%sodium

hypochlorite averagely indicated solubility percentage

as 70/53%. In this group, 6 samples show solubility per-

centage above 50% and 4 sample showed solubility per-

centage below 40%.

Solution with code number 2 included 2/5% sodium

hypochlorite. Tissue solubility had 07/27% average while

out of 10 samples one sample showed 50% solubility,

one sample showed negative solubility and other sam-

ples showed solubility under 50%.. solution number 3

included chlorhexidine+ benzalkoniumchloride showed

average of 39/32% tissue solubility and out of all sample

one sample showed solubility above 50% and other sam-

ples showed solubility below 50%. In addition, solution

number 4 included chlorhexidine+ 2% sodium dodecyl

sulfates showed solubility average as 83/34% while all

10 samples showed solubility below 40%. However solu-

tion number 6 included normal saline which was used

as control solution and showed average 66/0- %tissue

solubility. Out of 5 samples under study, 2 samples had

solubility below 10%, one sample zero solubility and 2

samples showed negative solubility.

RESULTS AND DISCUSSION

In comparing 6 groups, maximum solubility is related

to 5/25% sodium hypochlorite and minimum solubility

is related to 0/2% chlorhexidine which is after control

group. After 5/25% sodium hypochlorite, percentage of

solubility is respectively related to chlorhexidine+ 2%

sodium dodecyl sulfate, chlorhexidine+ 4% benzalko-

niumchloride and 2/5% sodium hypochlorite.

In addition, descriptive statistic table for 6 groups is

as follow:

Statistical analysis of ANOVA with 95% as con dence

level was performed by 6 groups. And p<0/05 indiçâted

that there is no signi ant différence (P=0/0).

In addition, in Hemogeneity of variances test (P<0.05),

variance of 6 group, has signi cant difference (P=0.011).

For comparing average of 6 groups we used Welch

test in which signi cant difference between groups was

observed (P=.00).

For pairwise comparing of groups, Tamhane test was

used. Results indicated that there is signi cant differ-

ence between group 1 (5/25% sodium hypochlorite) with

group 6 (normal saline) and group 5 (0/2% chlorhex-

idine) group 3 (chlorhexidine+ benzalkoniumchloride)

with group 6, group 4 (sodium dodecyl sulfate) with

group 6 and group 5 with group 6. It means that nor-

mal saline and chlorhexidine has no ability of solving

organic tissue.

On the other hand, there is not signi cant difference

between group 1 with group 2,3 and 4. It means that

solubility of these groups is approximate to solubility of

5/25% sodium hypochlorite.

Root treatment without operation is predictable

method for tooth protection which is withdrawn in case

of no treatment (Johnson et al, 2008). Initial etiologic

factor in formation of pulp waste and priapical bac-

teria were studied (Kandaswamy and Venkateshbabu

2010; Guerreiro-Tanomaru et al, 2011; Martin 1991;

Mohammadi and Abbott 2009, Portenier et al, 2002).

Micro-organisms may be existed in root canal, dentinal

tubules, secondary canals and apical strait (Kandaswamy

and Venkateshbabu 2010;Baumgartner et al, 2007; Iqbal

2012). In some dentinal teeth, even DEJ was infected

(Zehnder et al, 2003).

If cleaning is not performed appropriately, necrosis

residuals of soft tissue is acting as feeding resource of

Table 1. solutions under experiment

Solution

code number

Solution name Sample

number

1NaOCl 25/5%10

2NaOCl 5/2%10

3BKC 4% +CHX 2/0%10

4SLS 2% +CHX 2/0%10

5CHX 2/0%10

6NaCl 9/0%5

Samira Shahsiah et al.

44 EVALUATION OF TISSUE DISSOLUTION ABILITY OF MODIFIED CHLORHEXIDINE BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

DIAGRAM 1. Root dentine section which is covered