since the 1920 's , there have been reports in the literature which demonstrate the 
 preoccupation about the toothbrush contamination by microorganisms associated with mouth 
 infections , as well as their 
 transmissionthrough their bristles , acting as vehicle for the 
 bacterial reintroduction in the oral cavity . ( 2004 ) evaluated the 
 survival of microorganisms in toothbrushes , after their use for 1 week . the results 
 showed the presence of feasible bacteria in their bristles , with several kinds of forms , 
 from the beginning to the end of the experimental period , with prevalence of 
 gram - positive cocci for gram - negative bacilli , respectively . streptococcus 
 from the mutans group has been frequently associated with the 
 contamination of toothbrush bristles . during oral hygiene , the use of dentifrice has been indicated not only as a cosmetic 
 tool associated with flavor , but also a therapeutic agent to treat oral diseases , caries 
 and periodontal disease , for having certain chemical agents . some authors have investigated the 
 likelihood of some chemical agents present in the dentifrices acting on the reduction of 
 viable microorganisms that contaminate the toothbrush bristles after their use . triclosan is an antimicrobial agent used in dentifrices , which has some characteristics 
 such as having a broad - spectrum of antimicrobial activity , being non - ionic and , when 
 associated with zinc citrate or to gantrez , showing anti - plaque and anti - inflammatory 
 effects when used for periods longer than 6 months . considering its effective , nontoxic , cost - effective and easily applicable 
 characteristic , solutions based on triclosan - containing dentifrice have been tested for 
 the disinfection of toothbrushes contaminated in vitro by standardized 
 suspensions of s. pyogenes , staphylococcus aureus or 
 candida albicans . ( 2007 ) observed 
 that 24 h after the use of the toothbrushes , there was contamination of their bristles 
 by cariogenic and periodontopathogenic microorganisms . the results showed that oral 
 hygiene performed by the association of toothbrush with a dentifrice containing 
 triclosan reduced significantly the residual contamination of the bristles . propolis is a natural resinous substance , which results from the collection that 
 apis mellifera bees made from leaves , flowers and certain 
 barks . among its biological 
 activities , its antimicrobial 
 activity is outstanding and varies according to its flavonoid contents , which depend on 
 the vegetation of the collection area . 
 aloe vera is a plant of the liliaceous family , popularly known as 
 " babosa " . its mucilaginous gel is obtained from its leaves and has been largely studied 
 in the healthcare area due to its anti - inflammatory and antimicrobial 
 properties . according to barreto , et al . ( 2005 ) , aloe vera abounds with 
 aloeferon , which acts on the tissue healing . it contains acemannan , which is a 
 mucopolysaccharide with antiviral , antifungal and antimicrobial action , for activating 
 the immune system and stimulating the antibody production ; it also contains 
 anthraquinone , which is an antiseptic substance . propolis associated with aloe vera has caused great interest in 
 dentistry due their action against pathogenic microorganisms and inflammatory 
 properties . therefore , the goal 
 of this study was to evaluate in vitro the antimicrobial capacity of 
 the dentifrice containing aloe vera and propolis on the contamination 
 reduction of toothbrush bristles by streptococcus mutans standard 
 strain . fifteen toothbrushes were purchased ( sanifill leader vip , facilit odontolgica e 
 perfumaria ltda , curitiba , pr , brazil ) with the following characteristics : small head , 
 soft nylon bristles , with the same height , rounded tips , with 30 tufts . the handle of 
 each toothbrush was cut 3 cm far from the tip end to help placing the dentifrice onto 
 the bristles . the toothbrushes and their handles were individually packed for 
 sterilization in autoclave ( vitale , 12l , cristfoli equipamentos de biossegurana ltda , 
 campo mouro , pr , brazil ) . then , the toothbrushes were divided , randomly , into 5 brushing groups , with 3 
 toothbrushes in each group : - group i ( negative control ) : contamination of the toothbrush bristles and toothbrushing 
 for 1 min , without dentifrice ; - group ii : contamination of the toothbrush bristles associated with toothbrushing for 1 
 min , with fluoridated dentifrice ( sorriso , colgate - palmolive indstria e comrcio ltda , 
 so bernardo do campo , so paulo , brazil ) ; - group iii : contamination of the toothbrush bristles associated with toothbrushing for 
 1 min , with dentifrice containing triclosan associated with gantrez ( colgate total 12 , 
 colgate - palmolive indstria e comrcio ltda , so bernardo do campo , sp , brazil ) ; - group iv ( positive control ) : contamination of the toothbrush bristles associated with 
 toothbrushing for 1 min , without dentifrice , followed by irrigation with 10 ml of 0.12% 
 chlorhexidine gluconate ( periogard , colgate - palmolive indstria e comrcio ltda ) ; - group v : contamination of the toothbrush bristles associated with toothbrushing for 1 
 min , with dentifrice containing aloe vera and propolis ( forever bright 
 with aloe vera and bee propolis , forever living products , scottsdale , 
 az , usa ) . in each group , toothbrushing was performed on the flat enamel surface of a bovine tooth . 
 in order to obtain this surface , 5 bovine premolars were cut 2.0 cm long by 1.0 cm wide 
 under cooling using a high - speed dental drill with cylindrical diamond bur ( kg sorensen 
 indstria e comrcio ltda , barueri , sp , brazil ) . this size was compliant with the size 
 of the toothbrush head used in the study ( figure 
 1a ) . bovine premolar tooth , and enamel surface fixed on an acrylic resin block ( a ) to 
 facilitate the seizing for brushing ( b ) to make toothbrushing easier , the surface of the bovine tooth was fixed on an acrylic 
 resin ( jet , artigos odontolgicos clssico ltda , campo limpo paulista , sp , brazil ) block 
 ( 2.5 cm x 1.5 cm x 1.0 cm ) the flat enamel surface was left a few millimeters above the 
 level of the acrylic resin block , so that the toothbrush bristles had contact with this 
 surface only during brushing . then , the enamel surface / acrylic resin block set was 
 packed and sterile in an autoclave . for the brushing , 5 sets of the enamel 
 surface / acrylic resin block were randomly divided for each brushing group ( figure 1b ) . the standard strain of s. mutans ( atcc 25175 ) was used for the 
 contamination of the toothbrush bristles . its culture was made in a test tube with 10 ml 
 of bhi solution , incubated in an anaerobiosis jar under 37c for 7 days . after the 
 microbial growth , the samples were homogenized for 10 s in a tube shaker ( agitador de 
 tubos ; ap56 , phoenix , araraquara , sp , brazil ) . then , 3 qualified researchers ( a- msc , b- pfrb and c- slp ) performed the contamination 
 of the bristle brush , the dentifrice distribution on the bristles , the toothbrushing and 
 deposition of the bristles in the culture medium . the researchers were wearing sterile 
 gloves , which were changed at the end of treatment of each group . for the bristle contamination of each group , researcher a opened the sterile packing , 
 researcher b took out the toothbrush and researcher c spread 25 l of the standard 
 strain with a micropipette on the first 3 rows of bristles away from the handle . after the contamination , in groups ii , iii and v , the researcher a distributed the 
 dentifrices over the bristle area aided with the tip cut from its handle ( figure 2 ) . then , researcher b performed the brushing 
 for 1 min . in all groups , immediately after brushing , the researcher b trimmed the first 
 3 rows of bristles of each toothbrush using a scalpel blade no . 12 ( surgiblade , sunshine 
 int'l , miami , fl , usa ) , which was discarded at the ending of each group . cut tip handle to aid dentifrice placement onto the toothbrush bristles the trimmed bristles of each toothbrush were stored in an individually test tube with 3 
 ml of bhi solution , which were kept in anaerobiosis under 37c for 48 h. after , with a 
 sterile swab the sowing was made in triplicate in the mitis salivarius 
 - bacitracin medium . the samples were kept in anaerobiosis under 37c for 48 h. to evaluate the results of each group , scores were used according to the number of 
 colony forming units ( cfu ) , as shown in figure 
 3 . then , these data were submitted to the descriptive analysis and to the 
 mann - whitney statistical test at 5% significance level . the scores assigned to the cfu 's counted for each group are shown in table 1 , where a statistically significant 
 difference was found ( p<0.05 ) in the reduction of bristle contamination in groups ii , 
 iii , iv and v compared to group i. however , there was no statistically significant 
 difference among the groups that used the chemical agents to decontaminate the 
 toothbrush bristles ( figure 4 and figure 5 ) . score for colony forming units ( cfu ) , descriptive analysis and mann - whitney 
 statistical test roman numerals followed by different low case letters in 
 the vertical , differ to each other statistically ( p<0.05 ) . group i ( e ) and group iv 
 ( e+u ) characteristic of bacterial growth for group i , ii , iii , iv and v in the culture 
 medium oral health professionals must hence include instructions to post - hygiene care of the 
 toothbrushes in order to reduce the contamination and , consequently , minimize the 
 microbial transmission in the same individual from one niche to another . according to 
 bhat , et al . ( 2008 ) , the patient must be 
 instructed to change toothbrush constantly and store it in a moisture - free environment 
 in order to minimize the contamination . ( 2001 ) 
 established a toothbrushing time of 30 s , while nascimento , et al . the toothbrushing time established for all groups was 1 min . according to the results 
 presented by group i , this time was sufficient to contaminate the toothbrush bristles , 
 and to perform the decontamination in all groups which used chemical agents . ( 2000 ) reported that 
 the bristle and microorganism types affect toothbrush contamination . while , carranza , et 
 al . ( 2004 ) reported that 
 toothbrushes with nylon bristles accumulated less microorganisms than the ones with 
 natural bristles . in this study , the association of nylon bristles with the chemical 
 agents used can be considered as a factor which contributed to the effective 
 decontamination of the toothbrush bristles . in some studies , the head of the toothbrush was directly submerged in 
 the test tube for the analysis of the decontamination of bristles . in this study , the 
 bristles were trimmed and stored in individual test tubes , as previously 
 suggested . bacitracin antibiotic associated with the culture medium was used to inhibit the growth 
 of other bacterial species and to promote only the selective growth of s. mutans 
 strain , according to nascimento , et al . ( 1991 ) , 
 0.12% chlorhexidine gluconate presents essential characteristics due to its 
 substantivity associated with the bactericidal activity at high concentrations . however , 
 emilson and lindquist ( 1988 ) reported 
 the incapacity of chlorhexidine to eliminate permanently s. 
 mutans from the tooth surfaces . after toothbrushing without dentifrice in the group iv of this study , the 
 decontamination of the toothbrush bristles was performed by irrigation with 0.12% 
 chlorhexidine gluconate . the culture obtained from these bristles did not promote the 
 bacterial growth , and this method was proven effective for the decontamination of 
 toothbrush bristles for the strain used . ( 2008 ) in an 
 in vivo study involving s. 
 mutans , where the toothbrush bristles were decontaminated using 0.12% 
 chlorhexidine gluconate spray . in the present study , the form of dentifrice distribution on the toothbrush bristles may 
 have increased its contact with the microorganisms and , consequently , promoted its 
 action for the decontamination of the bristles . in groups ii and iii , both dentifrices were fluoridated , with a concentration of 1450 
 ppm , complying with anvisa requirements . although there was no significant difference 
 between the scores presented for cfu , the dentifrice from group ii presented some scores 
 lower than the ones obtained for the dentifrice from group iii . however , the dentifrice 
 used in group v does not contain fluoride in its formulation , and contains aloe 
 vera associated with propolis . according to lee , et al . ( 2004 ) , aloe vera 's has 
 anti - inflammatory , immune - stimulating , analgesic and antimicrobial activities against 
 oral microorganisms , among which s. mutans . the antimicrobial action of propolis is associated with its capacity of inhibiting the 
 glucosyltransferase activity , which is essential for s. mutans to 
 catalyze the formation of soluble and insoluble glycans , as well as to provide 
 adherence . some authors have reported that triclosan is not so 
 effective to inhibit it . according to the results of an in an in vitro study , the dentifrice containing triclosan 
 presented a significant antimicrobial action against standard strain of s. 
 mutans when compared to the dentifrice containing aloe vera 
 associated with propolis . in this study the significant reduction of the toothbrush bristle contamination is dependent on the 
 dentifrice formulation . the results 
 observed in the current study did not show significant difference in the reduction of 
 bristle contamination among the different dentifrices used in the groups . this could be 
 associated with the presence of detergents in their formulas , which is reported to aid 
 the reduction of survival of pathogenic species . in this study , the efficiency of dentifrice to reduce the 
 contamination of the toothbrush bristles may have also been supported by the action of 
 the sodium lauryl sulfate detergent , which is present in all dentifrices used . as there is no reported study using aloe vera associated with propolis 
 dentifrice to decontaminate the toothbrush bristles , further in vitro 
 and in vivo studies involving different bacterial types within the limits of this study , it may be concluded that all the chemical agents used 
 were effective to reduce the contamination by the standard s. mutans 
 strain on toothbrush bristles . the dentifrice containing aloe vera and 
 propolis reduced the contamination of toothbrush bristles , though without differing 
 significantly from the other groups that used chemical agents .
objectivesthis study evaluated in vitro the efficiency of aloe 
 vera and propolis dentifrice on reducing the contamination of 
 toothbrush bristles by a standard strain of streptococcus mutans 
 ( atcc 25175 ; sm ) , after toothbrushing . 
 material and methodsfifteen sterile toothbrushes were randomly divided into 5 toothbrushing groups : i 
 ( negative control ) : without dentifrice ; ii : with fluoridated dentifrice ; iii : with 
 triclosan and gantrez dentifrice ; iv ( positive control ) : without dentifrice and 
 irrigation with 10 ml of 0.12% chlorhexidine gluconate ; v : with aloe 
 vera and propolis dentifrice . in each group , 1 
 sterile bovine tooth 
 was brushed for 1 min , where the toothbrush bristles were contaminated with 25 l 
 of sm . 
 after toothbrushing , the bristles were stored in individual test tubes with 
 3 ml of bhi under anaerobiosis of 37c for 48 h. then , they were seeded with 
 sterile swab in triplicate in the mitis salivarius - bacitracin 
 culture medium . 
 the samples were kept under anaerobiosis of 37c for 48 h. scores 
 were used to count the number of colony forming units ( cfu ) . 
 the results were 
 submitted to the mann - whitney statistical test at 5% significance level . 
 resultsthere was statistically significant difference ( p<0.05 ) for the reduction of 
 bristle contamination comparing groups ii , iii , iv and v to group i. conclusionsit may be stated that after toothbrushing , the aloe vera and 
 propolis dentifrice reduced the contamination of toothbrush bristles by sm , 
 without differentiation from the other chemical agents used .