A SYSTEMATIC REVIEW EFFECTIVENESS OF 2% CHLORHEXIDINE ON REMOVAL OF E.FAECALIS BIOFILM IN ROOT CANAL: A SYSTEMATIC REVIEW

Dr. Mubssira Shaikh, Dr. Pradeep Shetty, Dr. Monika Chawla and Dr. Ekta Senga, Dr. Sharon Coelho and Dr. Neha Neekhara. Department of Conservative Dentistry and Endodontics, Dr. D. Y. Patil Vidyapeeth (DPU), DR. D. Y. Patil Dental College and Hospital, Pimpri, Pune-18 ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 5 (9), 1388-1394 1389 enterococcal surface proteins (Esp), gelatinase, cytolysin toxin, extracellular superoxide production, capsular polysaccharides, antibiotic resistance determinant) can facilitate the adherence of host cells and extracellular matrix, tissue invasions, immunomodulation effect and cause toxin mediated damage. 12 Actual thinking has recommended the implementation of evidence-based dentistry, which organizes studies involving the systematic review or meta-analysis. Systematic reviews use a strict methodological approach to search, select, evaluate, and analyze original data from primary sources. 13 Good scientific evidence is mandatory to elaborate clinical decisions, yet few systematic reviews or metaanalysis have been developed in Endodontics. 14 Previous studies using in vitro experimental models have confirmed the antimicrobial efficacy of CHX against E. faecali, while others using different study designs have not found same results. 14 Relevant clinical questions based on evidence regarding the resistance of E. faecalis to CHX should be further discussed.
Therefore, the aim of this study was to review findings on the antibacterial efficacy of CHX on removal of E. Faecalis biofilm in root canal using systematic review.
Focused Question:-What is the efficacy of 2% chlorhexidine for the removal of E.faecalis biofilm in freshly extracted human teeth using in vitro studies? Objective:-To evaluate the efficacy of 2% chlorhexidine on removal of E.faecalis biofilm in root canal.

Methods:-
Eligibility Criteria:-Inclusion Criteria:-1. Articles in English or those having detailed summary in English were included 2. Studies published between 1 st January 2005 to 31 st December 2015 were included 3. Studies in which setting was laboratory based were included 4. In vitro studies were included 5. Studies in which human extracted teeth were used as a sample were included 6. Studies in which 2% CHX was used as intervention were included 7. Studies that provide information about removal of E.faecalis biofilm using CHX were included. Study selection process:-In vitro and comparative studies were selected; however, only articles where the effect of 2% Chlorhexidine on removal of E. Faecalis biofilm in root canal in freshly extracted human teeth were included. Using different search strategies from the above mentioned key words and the combinations various electronic databases were searched. Total 1632 articles were identified through the database searching and 4 articles were identified through other sources. After thorough reading of tittles 1636 articles were selected. Further these records were assessed for any duplicates and 1608 articles were removed and 28 articles were screened for full text. Full text thorough readings of these, 21 articles were selected and were assessed for eligibility. Only 7 articles were qualified and 14 articles were excluded.8 articles were excluded as they use brain heart infusion (BHI) broth instead of freshly extracted human teeth and 2 articles were excluded as they used Trypticase soy agar plates were swabbed with E. Faecalis. 1 article was excluded as it was a review article. Another 3 articles were excluded as they did not qualify for the methodology selection.

Data Collection Process:-
Data collection process was done according to the consultation approved from our expert. First a Pilot Microsoft Excel Sheet was filled accordingly and then the expert was consulted for further progress. According to the data collected and the records selected the remaining Excel sheet was filled only with the data that was related to this study and retained.

Data Items:-
The headings under which the data was tabulated are Study ID where the number of studies that were selected was mentioned number wise. Various articles were included and so was the Name of the Author as an important factor.
Year of Publication to mention and specify the fixed time interval that was selected. Study Design was mentioned as to specify the type of study design for example whether the study was in vivo, in vitro or in situ. Sample Size was mentioned to specify the number of participants included in the study. Population/Products were included and this comprised of freshly extracted human teeth. Intervention was selected as the use of 2% chlorhexidine.  Discussion:-

Summary of evidence:-
The success of endodontic treatment is closely associated to the control of endodontic microbiota. Numbers of chemical irrigants have been suggested for use in the treatment of infected root canal. Several reviews may have been studied based on evidence regarding the resistance of E. faecalis to CHX. This systematic review has been attempted to find the best available evidence relative to review findings on the antibacterial efficacy of CHX on removal of E. Faecalis biofilm in root canal system. However, it is difficult to draw conclusions from the articles selected as they cannot be compared directly due to the diversity of eligibility criteria's, assessment methods and outcomes.
Seven studies met the inclusion criteria established for the present investigation.

Mohammadi Z et al in 2008
compared the antimicrobial substantivity of BioPure MTAD, 2% chlorhexidine (CHX) and 2.6% sodium hypochlorite (NaOCl). One hundred and ten dentin tubes prepared from human maxillary incisors were infected for 14 days with E.faecalis. The specimens were divided into five groups as follows: CHX; BioPure MTAD; NaOCl; infected dentin tubes (positive control); and sterile dentin tubes (negative control). Dentin chips were collected with round burs into Brain Heart Infusion (BHI) broth. After culturing, the number of colony-forming units (CFU) was counted. In all experimental groups, CFU was minimum after treatment (day 0), and the results obtained were significantly different from each other at any time period (P < 0.05). After treatment, the NaOCI group and BioPure MTAD group showed the lowest and highest number of CFU, respectively. In conclusion, the substantivity of BioPure MTAD was significantly greater than CHX and NaOCl [15] .

Mehrvarzfar P et al in 2011 compared the effect of a diode laser and common disinfectants used in
combination on mono-infected dental canals. One hundred and six single-rooted human premolars were prepared and contaminated with E.faecalis. After two weeks of incubation, samples were divided into two experimental groups (n = 48) and two control groups (n = 5). Absence of growth was seen only for MTAD plus laser treatment. Complete elimination of E. faecalis was seen only for the combination of MTAD with diode laser irradiation. Combination therapy with MTAD irrigation and diode laser irradiation, within the parameters used in this study, can be recommended as an effective treatment option for complete elimination of E. faecalis from the root canal system [16] .

Murad et al in 2012
reported that the antimicrobial efficacy of 2.5% and 5.25% NaOCl, 2% gel and liquid CHX and MTAD against E.faecalis biofilms on human dentin. The antimicrobial activity of the test irrigants were assessed through CFU counts. Biofilm formation over the dentin surface was ensured by SEM analysis. Results showed no statistic difference among CHX gel, 2.5% and 5.25% NaOCl. However, the CHX liquid and MTAD were less effective than 2.5% and 5.25% NaOCl. Only CHX liquid and MTAD had differences in its efficacy depending on the time. The most effective irrigants in eliminating E. faecalis biofilms were 2.5% and 5.25% NaOCl and 2% CHX gel, at all the tested time intervals, in comparison to CHX liquid and MTAD [17] .

Hasheminia S et al in 2013 observed antibacterial activity of common root canal irrigants with a combination
technique against intratubular E.faecalis. Seventy five specimens were contaminated with E. faecalis and divided into five experimental groups (n = 15). These groups were irrigated with 2% chlorhexidine (CHX), 3% hydrogen peroxide (H2O2), 5.25% sodium hypochlorite (NaOCl), CHX/H2O2 and sterile saline (control). Surface and deep dentinal chips were collected for each sample. After incubation, the numbers of colonyforming units (CFUs) were counted. In the surface dentin, CHX, NaOCl, and CHX/H2O2 had significantly higher antibacterial activity than H2O2 (P < 0.05). In the deep dentin, NaOCl and CHX/H2O2 had significantly higher antibacterial activity than CHX and H2O2 (P < 0.05). CHX/H2O2 had similar antibacterial effectiveness to NaOCl in both surface and deep dentinal tubules. This combination can be considered a potentially useful irrigant for root canal treatment [18] .

Valera MC et al in 2013
detected the antimicrobial activity of auxiliary chemical substances and natural extracts on C. albicans and E. faecalis inoculated in root canals. Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1) 2.5% sodium hypochlorite (NaOCl), G2) 2% chlorhexidine gel (CHX), G3) castor oil, G4) glycolic Aloe Vera extract, G5) glycolic ginger extract and G6) sterile saline (control). The 1393 samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1st collection, after instrumentation; and 2nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37°C for 48 hours. NaOCl and CHX completely eliminated the microorganisms of the root canals. Reduction of CFU/mL at the 1st and 2nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6. It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity [19] .
6. María Ferrer-Luque C et al in 2014stated that effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. They compare the residual antimicrobial activity of 0.2% cetrimide, and 0.2% and 2% chlorhexidine in root canals infected with E.faecalis.After root canal preparation, root canals were irrigated with 17%EDTA to remove the smear layer. The roots were randomly divided into three experimental groups (n526) according to the final irrigating solution: Group I, 5 mL 0.2% cetrimide; Group II, 5 mL 0.2% chlorhexidine; and Group III, 5 mL 2% chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P,0.05. The highest survival value was found with 2% chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalis growth was detected in 69.23% specimens in Groups I and II, and in 34.61% specimens of Group III. There were no significant differences between 0.2% cetrimide and 0.2% chlorhexidine. Final irrigation with 2% chlorhexidine showed greater residual activity than 0.2% chlorhexidine and 0.2% cetrimide in root canals infected with E. faecalis [20] .
7. Noites R et al in 2014 testing various irrigants, sodium hypochlorite, chlorhexidine, and ozone gas, alone or in combination, were effective against E.faecalis and C.albicans. 220 single rooted teeth, were inoculated with C.albicans and E.faecalis.Sodium hypochlorite, chlorhexidine, and gaseous ozone alone were ineffective in completely eliminating the microorganisms. The association of chlorhexidine at 2%followed by ozone gas for 24 seconds promoted the complete elimination of Candida albicans and Enterococcus faecalis. Flow cytometry shows that ozone and chlorhexidine act differently, which could explain its synergic activity. This new disinfection protocol, combining irrigation with chlorhexidine at 2% and ozone gas for 24 seconds, may be advantageous when treating infected root canals [21] .

Limitations:-
These studies do not give concrete conclusions due to inadequate search of literature because of less access to search forums, failure to evaluate quality of studies, failure to exclude poorly designed studies, inappropriately combining heterogeneous studies, smaller sample sizes, availability of relevant articles in different languages other than English.

Conclusion:-
Within the present review limitations, It was shown that, 2%CHX has a better efficacy when it is used in combination with ozone gas, this review also suggest that the antibacterial residual effect of 2% CHX would depend on its concentration and the length of its application time. It can be demonstrated that 2% CHX was a potential useful solution for the elimination of E. Faecalis biofilm due to its substantivity. Also, it has shown good efficacy when compared to other irrigants in decreasing the microbial load from the surface dentin of root canal system.
However two reviews shown that the substantivity of BioPure MTAD was significantly higher than CHX. Also the combination therapy consisting of irrigation and laser irradiation, Biopure MTAD, is an effective treatment option as compared to CHX for eliminating E. faecalis from the root canal system.
In summary, the disinfection of the root canal system produced by action of CHX reduces the remaining endodontic microbiota, which favors the achievement of a higher level of success of the endodontic treatment.