achieving predictable long - term success of root canal treatment requires effective debridement and disinfection of root canal system . this is not always achieved completely because of anatomical complexity and the limitation in accessing the canal system by instruments and irrigants . candida albicans is the most common fungus seen in the root canals , 21% in primary infections and 18% in cases of retreatments . it can survive harsh conditions due to biofilm formation and the physicochemical properties of the microorganisms help them to modify according to the prevailing environmental and nutritional conditions . biofilm helps in resisting the destruction of the fungus by making them thousand times more resistant to phagocytosis , antibodies and antimicrobial agents . this is attributed to the protective barrier provided by the extracellular matrix . c. albicans is also resistant to calcium hydroxide , which is the most commonly used intracanal medicament . sodium hypochlorite has remained a popular root canal irrigant because of its antimicrobial potential and its ability to dissolve organic matter . however , it is not only irritant to the periapical tissues , but also inherently possesses certain disadvantages such as staining of instruments , burning of surrounding tissues , unpleasant taste , high toxicity , corrosive to instruments , inability to remove the smear layer , reduction in elastic modulus and flexural strength of dentin . propolis is a brownish resinous substance collected by bees mainly from plants , which is used to reinforce their hives and keep the environment aseptic . it is a potent antimicrobial , antioxidant and anti - inflammatory agent due to the presence of flavonoids , phenolics and other aromatic compounds . azadirachta indica ( neem ) is the most commonly used traditional medicinal plant of india . each part of the neem tree has some medicinal property and is thus commercially exploitable . neem elaborates a vast array of biologically active compounds that are chemically diverse and structurally complex . neem leaf and its constituents have been demonstrated to exhibit immunomodulatory , anti - inflammatory , antifungal , antibacterial , antiviral , antioxidant , antimutagenic and anticarcinogenic properties . the present study is aimed to explore newer herbal irrigants , which as potential antimicrobial agents in the inhibition of c. albicans in comparison to sodium hypochlorite . a pure culture of c. albicans atcc 10231 ( himedia , mumbai l. no . 443 - 207 ) was inoculated on sabouraud dextrose agar ( himedia , mumbai ) , incubated at 37c overnight and adjusted to an optical density of one with sterile brain - heart infusion broth . propolis ( herbal biosolutions , delhi ) was prepared by diluting a 33% commercially available alcoholic extract using warm saline in a ratio 2:1 , to form an 11% alcoholic extract . alcoholic extract of neem was prepared using 25 g of fresh neem leaves powder of 99% purity ( the indian neem tree company , mumbai ) was added to 50 ml of absolute ethanol ( sterling chemicals and alcohols pvt . ltd . , mixture was macerated for 1 - 2 min , then extract was filtered through muslin cloth for coarse residue and then through filter paper for finer residue . single rooted type 1 vertucci 's classification human mandibular premolar teeth were sectioned below the cementoenamel junction to obtain a standardized tooth length of 8 mm . the teeth were cleaned of superficial debris , calculus , tissue tags and stored in normal saline . the root canals were then instrumented using the crown down technique and rotary instruments to an apical size of protaper f3 . a total volume of 2 ml of 5% sodium hypochlorite ( prime dental products private limited , thane and maharashtra ) was used between each instrument during the cleaning and shaping procedure . the concave tooth surface was minimally grounded to achieve flat surface to enable placement in tissue culture wells exposing the root canal surface to c. albicans to form a biofilm . the samples were then sterilized by ultraviolet radiation in a biosafety cabinet ( accumax india , new delhi ) and placed in the wells of tissue culture plates . the cultured yeast was inoculated in the wells containing tooth samples at 37c for 2 days . the samples were divided into five experimental groups with 10 samples each and irrigated with 3 ml of each irrigant for 10 min . group 1  propolisgroup 2  mcjgroup 3  a. indica ( neem)group 4  5% sodium hypochloritegroup 5  sterile saline . group 3  a. indica ( neem ) group 4  5% sodium hypochlorite group 5  sterile saline . sterile paper point technique was used for sampling of root canals and inoculated in sabouraud dextrose agar and incubated at 37c for 24 h in a petridish , which was then analyzed by the digital colony counter ( spectronics india , haryana ) and the readings were subjected to statistical analysis using analysis of variance and post hoc tukey tests . a pure culture of c. albicans atcc 10231 ( himedia , mumbai l. no . 443 - 207 ) was inoculated on sabouraud dextrose agar ( himedia , mumbai ) , incubated at 37c overnight and adjusted to an optical density of one with sterile brain - heart infusion broth . propolis ( herbal biosolutions , delhi ) was prepared by diluting a 33% commercially available alcoholic extract using warm saline in a ratio 2:1 , to form an 11% alcoholic extract . alcoholic extract of neem was prepared using 25 g of fresh neem leaves powder of 99% purity ( the indian neem tree company , mumbai ) was added to 50 ml of absolute ethanol ( sterling chemicals and alcohols pvt . ltd . , mixture was macerated for 1 - 2 min , then extract was filtered through muslin cloth for coarse residue and then through filter paper for finer residue . single rooted type 1 vertucci 's classification human mandibular premolar teeth were sectioned below the cementoenamel junction to obtain a standardized tooth length of 8 mm . the teeth were cleaned of superficial debris , calculus , tissue tags and stored in normal saline . the root canals were then instrumented using the crown down technique and rotary instruments to an apical size of protaper f3 . a total volume of 2 ml of 5% sodium hypochlorite ( prime dental products private limited , thane and maharashtra ) was used between each instrument during the cleaning and shaping procedure . the concave tooth surface was minimally grounded to achieve flat surface to enable placement in tissue culture wells exposing the root canal surface to c. albicans to form a biofilm . the samples were then sterilized by ultraviolet radiation in a biosafety cabinet ( accumax india , new delhi ) and placed in the wells of tissue culture plates . the cultured yeast was inoculated in the wells containing tooth samples at 37c for 2 days . the samples were divided into five experimental groups with 10 samples each and irrigated with 3 ml of each irrigant for 10 min . group 1  propolisgroup 2  mcjgroup 3  a. indica ( neem)group 4  5% sodium hypochloritegroup 5  sterile saline . group 3  a. indica ( neem ) group 4  5% sodium hypochlorite group 5  sterile saline . sterile paper point technique was used for sampling of root canals and inoculated in sabouraud dextrose agar and incubated at 37c for 24 h in a petridish , which was then analyzed by the digital colony counter ( spectronics india , haryana ) and the readings were subjected to statistical analysis using analysis of variance and post hoc tukey tests . readings of microbial count obtained from digital colony counter after irrigation with respective irrigant were as follows : table 1 . mean and standard deviation showing inter group differences obtained from the readings of digital colony counter the mean and standard deviations obtained were as follows . microbial count was maximum in the saline group and minimum in propolis and sodium hypochlorite groups . absolute washout of c. albicans biofilm was observed in 8 out of 10 samples of propolis and sodium hypochlorite groups . neem group also showed a higher antimicrobial efficacy as compared with mcj and saline groups . saline ( negative control ) had least antimicrobial activity as expected . except for comparison between propolis and sodium hypochlorite , all the between group differences were statistically significant . the order of efficacy of different groups was as follows : propolis ~ sodium hypochlorite > neem > mcj > saline this study was conducted on c. albicans because these microorganisms are commonly encountered in recalcitrant endodontic infections . c. albicans has an initial period of adherence ( 0 - 2 h ) followed by subsequent microcolony formation ( 2 - 4 h ) . dimorphic switching occurred thereafter with a transition from budding - yeast forms to filamentous pseudo- and true - hyphal forms ( 4 - 6 h ) . micro - colonies then become interlinked by the hyphal extensions , forming a confluent monolayer ( 6 - 8 h ) . the complexity of the biofilm increases with time , taking on 3d architecture with spatial heterogeneity as it matured ( 8 - 48 h ) . the biofilm after 24 and 48 h consists of a mixture of yeast cells , pseudohyphae and true hyphae . filamentous forms were the most important factor in the 3d architecture , with yeast cells located in the basal layer . c. albicans mutants that are deficient in the production of hyphae have demonstrated an inability to form 3d biofilms . therefore , the dimorphic switching observed in this species is a pivotal factor for biofilm formation and the pathogenic potential of c. albicans , which is why the 48 h biofilm model was used . sodium hypochlorite is the most commonly used irrigating solution in clinical practice because of its tissue dissolution and antimicrobial activity , making it an irrigating solution of choice irrespective of its several undesirable characteristics such as tissue toxicity , risk of emphysema , allergic potential and disagreeable smell and taste . ayhan et al . demonstrated that sodium hypochlorite lowered colony forming units below the limit of detection after 10 s in the case of c. albicans . propolis exhibits antimicrobial , anti - inflammatory , healing , anesthetic and cariostatic properties . according to takaisi - kikuni and schilcher , it prevents fungal cell division and also breaks down fungal cell wall and cytoplasm similar to the action of some antibiotics . reported the antimicrobial action of propolis to be due to flavonoids and esters of phenolic acids . the ph chosen for propolis was six based on the results of the study conducted by ivanaji et al . since the inhibitory effect of propolis was the strongest in a slightly acidic environment ( ph = 6 ) . in an inflammatory process there is a slight decrease of ph ; thus , it would be most beneficial to use the extract of propolis of slightly acidic ph . , acetone and ethanolic extracts were found to be more active toward most microorganisms . as for neem , the ethanolic extracts performed better than the aqueous extract , therefore to standardize we prepared both our test solutions using ethanol . a study conducted grange and davey showed the antimicrobial efficacy of propolis against enterococcus species , staphylococcus aureus and c. albicans . it also showed antibacterial efficacy against escherichia coli , achromobacter , sarcina lutea and morganella morgani . a. indica ( neem ) ( ph = 6.8 ) has antimicrobial properties due to the presence of alkaloids , glycosides , saponins , flavonoids , steroids , anthraquinone and tannic acid . bohora et al . have concluded that neem leaf extract has a significant antimicrobial effect against c. albicans . acidic ethanolic extract was found to be better than aqueous extract in cases of c. albicans . neem has a wide spectrum of antimicrobial action ; against gram - negative and gram - positive microorganisms , including m. tuberculosis , m. pyogenes , streptococcus mutans and enterococcus faecalis . furthermore , effective against certain human fungi including trychophyton , epidermophyton , microsporum , trichosporon , geotricum and candida . . the beneficial antimicrobial effects may be the result of acubin , l - asperuloside , alizarin , scopoletin and other anthraquinones . showed that mcj showed no significant activity against c. albicans , which might be due to the fact stated by jainkittivong et al . who showed that in case of m. citrifolia fruit longer the contact time , higher is the inhibitory effect . the contact time found to be effective was 45 min , but in our study we took 10 min to standardize the procedure and simulate a clinical situation . it has antimicrobial action against pseudomonas aeruginosa , proteus morgaii , s. aureus , bacillus subtilis , e. coli , salmonella , shigella , e. faecalis and c. albicans . the shelf lives of ethanolic extract of propolis is 2 years , for neem leaf extract is 3 years and mcj is 3 years when not opened and 2 years after opening , if stored properly , as per the manufacturer 's instructions . compared the antibacterial activity of propolis and calcium hydroxide against c. albicans , but the drawbacks of the study was that the biofilm model was not used thereby not simulating clinical condition and other herbal irrigants were not compared in the study . bohora et al . compared the antifungal efficacy of neem leaf extract against c. albicans , but again the biofilm model was not used . until date , no study has been conducted comparing all these herbal irrigants with sodium hypochlorite in a biofilm model against c. albicans and therefore , this study holds ground for future research . according to the results of the study , we see a promising herbal irrigant in propolis against c. albicans in root canal infections . under the limitations of this study , it was concluded that : 
 propolis performed equally well as sodium hypochlorite against c. albicans biofilm formed on extracted tooth surface.a . propolis performed equally well as sodium hypochlorite against c. albicans biofilm formed on extracted tooth surface .
introduction : endodontic infections are polymicrobial in nature . 
 candida albicans is the most common fungus isolated from failed endodontic cases . 
 the constant increase in antibiotic resistant strains and side - effects caused by synthetic drugs has prompted researchers to look for herbal alternatives such as propolis , morinda citrifolia and azadirachta indica ( neem ) etc . 
 , since , the gold standard for irrigation , i.e. , sodium hypochlorite has many disadvantages.materials and methods : extracted human mandibular premolars were biomechanically prepared , vertically sectioned , placed in tissue culture wells exposing the root canal surface to c. albicans grown on sabouraud dextrose agar to form a biofilm . at the end of 2 days , all groups were treated with test solutions and control for 10 min and evaluated for candida growth and number of colony forming units . 
 the readings were subjected to statistical analysis using analysis of variance and post hoc tukey tests.results:sodium hypochlorite and propolis groups exhibited highest antimicrobial efficacy against c. albicans with no statistically significant difference . 
 it was followed by the a. indica ( neem ) group . 
 m. citrifolia had limited antifungal action followed by the negative control group of saline.conclusion:according to the results of this study , propolis can be used as an effective antifungal agent similar to that of sodium hypochlorite , although long - term in vivo studies are warranted .