# Introduction ral hygiene is the practice of keeping the mouth and teeth clean to prevent dental problems like, dental caries, gingivitis, periodontitis and bad breath 1 . Tooth brushing, tongue cleaning, flossing, mouth rinsing with disinfectant mouth washes are some of the methods for maintaining oral hygiene. Tooth brushing is the most effective and commonly used method among them. Along with the brushing methods, disinfection of toothbrush is also equally important for maintenance of health of oral tissues 1 . Toothbrushes often become contaminated with microorganisms which originate not only from oral cavity but also from environment in which they are stored 2, 3,4 . Wet environment of bathroom, dispersed aerosols from toilet flushing and contaminated finger contact contribute to toothbrush contamination. Several families generally store their toothbrushes in a common container which can lead to cross-infection.There is a possibility of re-infection when the individual uses the contaminated toothbrush. In 1920, Cobb was the first investigator to report the recurrence of infection in mouth in patient using contaminated toothbrush. When patient was advised to soak the toothbrush in alcohol before and after using it patient recovered from disease 5 . Glass and Shapiro 6 observed that changing the toothbrush at short intervals, helped patient achieve elimination of inflammatory disease symptoms, suggestive that toothbrush acted as a reservoir for microorganisms capable of producing diseases. Few studies have also reported chances of bacteremia and other systemic problems due to the use of contaminated toothbrush 7 . There is a need of disinfection of toothbrush, which can be done by methods which acts rapidly, costeffective, non-toxic and which can be easily implemented. Various methods for toothbrush disinfection have been listed in literature like immersion in antimicrobial solution, use of anti-bacterial tufted toothbrushes, UV sterilization etc 8 . Based on this, the present study was done to compare the efficiency of different antimicrobial solutions for disinfection of toothbrush. # II. # Materials and Methods The present study was done in Manipal College of Dental Sciences, Manipal. Permission from ethical committees of Manipal College of Dental Sciences and Kasturba Medical College, Manipal were taken. A total of sixty (volunteers) dental graduates aged in the range of 22-27 years were selected for the study. They were explained verbally about the study and they were language they could easily understand (Kannada or English). Written consent and contact information was collected from the volunteers. It was ensured that the selected volunteers are not taking any antimicrobial substances or antibiotics. Following this a routine dental checkup and oral prophylaxis was performed on the selected volunteers and plaque & gingival scores were brought down to zero. Five antimicrobial mouth rinses containing different active compounds namely 0.9% saline, 3% hydrogen peroxide, mouthwash 0.2% Chlorhex-idinegluconate, essential oils and Cetylpyridinium chloride along with tap water as control were selected to conduct the study. For purpose of standardization, same brand of toothbrush (Colgate, medium hard) and toothpaste (Colgate) were provided to all the volunteers. Toothbrushes were labeled as T1-T10 (Tap watercontrol), T11 -T20 (3% Hydrogen peroxide), T21 -T30 (0.9 % Saline), T31-T40 (0.2% Chlorhexidinegluconate), T41 -T50 (essential oils), T51-T60 (Cetylpyridinium chloride).The first group of ten volunteers were asked to brush using the standard modified bass technique for 3 min, twice daily for three days using the toothbrush and toothpaste provided to them. Following which they were instructed to rinse their brushes under tap water for 20 seconds, shake and leave the toothbrush to air dry in bathroom. In the same manner remaining five groups with ten subjects were asked to rinse their brushes under tap water for 20 seconds, shake well and keep the toothbrush in 3% hydrogen peroxide, 0.9% saline, 0.2% Chlorhexidinegluconate, essential oils and cetylpyridinium chloride containing mouthwashes respectively for 10 minutes. The tooth brush head was completely immersed in the disinfectant. A small sterile white bottle was provided to volunteers to put the disinfectant and to immerse brush head in disinfectant. Volunteers belonging to 3% hydrogen peroxide, 0.9% saline, 0.2% Chlorhexidinegluconate , essential oils and cetylpyridinium chloride mouthwashes groups were asked to dip the brush head in 1:1 dilution of the solution respectively. After ten minutes of immersion in disinfectant solution, volunteers were instructed to take out the toothbrush head from it and shake it once to remove the excess disinfectant solution. After this, volunteers were asked to keep their toothbrushes erect with its head facing upwards and left it for drying. Volunteers were given reminders for all the three days to follow the post-brushing instructions with the help of text messages in morning and at night. Volunteers were asked to return the toothbrush after three days. Toothbrushes were collected from the volunteers, placed in a sterile box and transported within an hour to the laboratory for microbiological analysis. For the microbiological analysis, back and handle of each toothbrush was disinfected with cotton soaked in 70% isopropyl alcohol (spirit), following which each toothbrush head (pre labeled as T1 to T60) was immersed in separate 10 ml of thioglycolate broth solution bottles and shaken for 2 minutes to transfer the microbial content present on bristle surface to the broth solution. Each broth solution was subjected to vortexing for 3 minutes, following which 1:10 and 1:100 dilutions were made for each broth solution in small vials using preset standard pipettes. Dilutions were labeled as T1-1:10 and T1-1:100 and same for remaining broth solutions till T60 -1:10 to T60-1: 100. After this, freeze dried blood agar plates were taken and labeled for example as follows, T1 undiluted, T1-1:10 dilution and T1-1:100 dilutions corresponding to each broth solution and its respective dilutions. Same was done for the remaining 59 broth solutions and their dilutions till T60 undiluted, T60-1:10 dilution and T60-1:100 dilutions. With the help of sterilized end of inoculation loop, sub culturing (spreading) of individual pre labeled blood agar plates was done using 10µl of its corresponding solution. The inoculated plates were then incubated at 37C for the next 48 hrs. At the end of 48 hrs, blood agar plates were recovered from incubator for microbial counting. # III. # Results Sixty volunteers between the age group of 22 to 27 years (mean age=?) participated in this study. The toothbrushes were labeled and subjected to microbial analysis after twice daily use for three days to determine the total number of CFUs. The mean log CFU and standard deviation after treatment with six different solutions used to disinfect toothbrushes is presented in Table 1. The mean difference in the log CFUs among the six groups was analyzed using ANOVA and they were significantly different (P< 0.001). 3 % Hydrogen peroxide (4.24± 1.0) produced the lowest number of CFUs among all the six groups followed by mouthwashes containing 0.2 % Chlorhexidinegluconate (4.47 ± 1.7) and essential oils(4.75 ± 1.2) respectively. Dunnett post hoc analysis was performed among the six respective groups with the group using water as the control is presented in Table 2. 3 % Hydrogen peroxide (MD= -2.02, p<0.001), 0.2% chlorhexdinegluconate mouthwash (MD= -1.79, P<0.001) and essential oils mouthwash (MD=-1.51, P<0.008) gave a significantly lower CFUs score when compared with water as the disinfectant. Saline and cetylpyridinium chloride containing mouthwash failed to produce a significant difference in the number of CFUs when compared with that of water. # Discussion Overview of the literature suggests that contamination of toothbrush and its role in transmission of oral and systemic disease 7,10,11 . Several studies (a-log transformed, b-one way ANOVA, *-p value <0.05 ) conducted in past used different disinfection techniques like UV radiation 8,9 , microwave irradiation 12 , boiling water, chemical agents 13 like hydrogen peroxide, cetylpyridinium chloride, chlorhexidine , etc., had shown reduction in microbial count on toothbrush bristles suggesting need for toothbrush disinfection. The present study was undertaken to analyze the disinfection property of five different antimicrobial solutions (saline 0.9%,hydrogen peroxide 3%, 0.2% Chlorhexidinegluconate , essential oils and Cetylpyridinium chloride containing mouthwashes) and tap water as control. Sixty volunteers with average age ranging from 22 to 27 years were randomly assigned one of the six groups with ten subjects in each. Volunteers were asked to brush twice daily for three days and follow the post brushing disinfection instructions given to them. At the end of three days used toothbrushes were collected and sent for microbiological analysis. Hydrogen peroxide showed maximum reduction in microbial count (MD= -2.02, p<0.001) .This result agrees with the finding of a study done Sogi et al 14 .The antimicrobial activity of hydrogen peroxide is based on release of nascent oxygen and its effervescence removes the debris from otherwise in accessible regions 15 . Chlorhexidinegluconate that was used as disinfectant showed next least microbial count (MD= -1.79, P<0.001). Chlorhexidine destroys the integrity of cell membrane, penetrates the cell and precipitates the cytoplasmic proteins leading to bacterial cell destruction. It acts mainly against gram positive organisms, some gram negative bacteria and fungi 16 . Essential oils containing mouthwash (MD=-1.51, P<0.008) showed comparable results with that of chlorhexidinegluconate. Essential oils cause bacterial cell wall destruction, their enzymatic inhibition and extraction of bacterial polysaccharide 17 . Volunteers in group six which used cetylpyridinium chloride containing mouthwash as disinfectant showed reduction in microbial count but much less in comparison with other three groups. A similar result was obtained in previous study conducted by Meier S et al 1996 using cetylpyridinium chloride spray as disinfectant for toothbrushes 18 . It was observed that the brushes of volunteers in group 3 using 0.9% saline and group 1 using tap water showed maximum microbial count on toothbrush bristles suggesting these two as least effective method for toothbrush disinfection. Similar results were also obtained in previous studies 19,20 . The present study used a wide range of disinfectant solutions that are commercially available and compared it with the routine use of tap water for cleaning toothbrush. Results suggest the use of disinfectant to be beneficial in reducing the microbial count. The study design incorporated the use of toothbrush disinfectant twice daily for three days to correlate it with the lifestyle pattern of individuals to obtain effective results. Further qualitative in vivo studies using disinfectant methods that are economical, nontoxic and easy to use can be done. # Conclusion The present study shows that use of 3% hydrogen peroxide to disinfect toothbrush is one the most effective methods to decontaminate it followed by using mouthwashes containing 0.2% chlorhexidinegluconate and essential oils as disinfectants. # P value 1![Figure 1 : Picture showing microbial colonies on red blood agar plates of samples collected from group 1(Tap water),group ( .2 % Chlorhexidine gluconate) and group (3% Hydrogen peroxide) respectively](image-2.png "Figure 1 :") 1DisinfectantNumRange(LogPgroupsber ofn ±CFU)valucaseSDMinimMaxime bs(LoumumgCFU) aWater106.274.97.60.00±1*0.83% H 2 O 2104.243.04.2±1.0.9% Saline106.134.86.9±0.7.2%104.473.06.9Chlorhexdineglu±conate1.7mouthwashEssentialoils104.753.07.0mouthwash±1.2Cetylpyridinium105.483.06.8chloride±mouthwash1.0D D D D ) J( * CADuarte PCMarcondes ATRayel * TransmissibilidadeDa Microbiotabucalemhumanos * Microorganisms on toothbrushes at day-care centers EMalmberg DBirkhed GNorvenius JGNoren GDahlen ActaOdontolScand 52 1994 * The microbial contamination of toothbrushes. A pilot study SSTaji AHRogers Aust Dent J 43 1998 * Investigations into the microbial contamination of toothbrushes JVerran AALeahy-Gilmartin Microbios 85 1996 * Toothbrushes as a cause of repeated infections of the mouth CMCobb Boston Med Surg J 183 1920 * Oral inflammatory diseases and the toothbrush RTGlass SShapiro J Okla Dent Assoc 82 1992 * Relationship of bacteremia to toothbrushing in patients with periodontitis CrawfordjjSconyersjr J Am Dent Assoc 87 1973 * The effectiveness of a u-v toothbrush sanitizing device in reducing the number of bacteria ,yeasts and viruses on toothbrushes RTGlass JensenHg JOkla DENT Assoc 84 1994 * Reduction in bacterial contamination of toothbrushes using the Violet ultraviolet light activated toothbrush sanitizer LiyBoylanr Simeonoval Sherwing CraKreismannj Am J Dent 21 2008 * Persistence of group A beta haemlytic streptococci in toothbrushes and IBrool Goberae * Contaminated toothbrushes and pharyngitis H Arch Otolaryngol Head Neck Surg 125 479 1999 * Evaluation of sterilization of toothbrushes in a microwave oven (in vitro study) JChibebeJr Pallos Rev Biocienc 7 2001 * Contaminated toothbrushes and their disinfection SDCaudry AKklitorinos ECChan J Can Dent Assoc 61 1995 * Contamination of toothbrush at different time intervals and effectiveness of various disinfecting solutions in the contamination of toothbrush SSogi Subbareddy SKiran J Indian Soc.Pedo.Prev Dent 20 3 2002 * A study of toothbrush contamination at different time intervals and comparative effectiveness of various disinfecting solutions in reducing toothbrush contamination GNavneet SKaur J Indian Soc.Pedo.Prev Dent 14 1996 * Investigations into the microbial contamination of toothbrushes JVerran AALeahy-Gilmartin Microbios 85 1996 * Antimicrobial mouthrinses: overview and update. Mandel, I.D Journal of the American Dental Association 1939. 1994 * An in vitro investigation of the efficacy of CPC for use in toothbrush decontamination SMeier CCollier MGScaletta JStephens RKimbrough JDKettering J Dent Hyg 70 1996 * Bacterial Contamination and Decontamination of toothbrushes after use AMehta PSSequeira GBhat NYSJ 2007 * The potential use of chlorhexidine (CHX) and Hexetidine containing mouth rinse in maintaining toothbrush sterility WHAznita ARFathilah J.Med.Sci 6 1 2006 * Effectiveness of different cleanser solutions on the microbial contamination of toothbrushes MohammadDhifaf Saleh Journal of Kerbala University 9 3 2011 Scientific * Edson Yukio Komiyama * GraziellanuernbergBack-Britoi * Evaluation of alternative methods for the disinfection of toothbrushes IvanBalducci ; CristianeyumiKoga-Ito Braz. oral res 24 1 Jan. Mar 2010 * Izabel Yoko Ito:Antimicrobial spray for toothbrush disinfection: An in vivo evaluation SandraSato ElzaHelenaViníciuspedrazzi GuimarãesLara RubensHeitorpanzeri Ferreira De Albuquerque Quintessence internationalVol * Residual contamination of toothbrushes by microorganisms KKozai TIwai KMiura J Dent Child 56 1989 * Microbial contamination of toothbrushes MBDayoub DRusilko AGross J Dent Res 56 10 706 1977. november/december 2005 * Comparative effectiveness of various disinfecting solutions inpreventing toothbrush contamination RMythili Sreedhar MJaya J Indian Soc Periodontal 21 2 1997