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 Table of Contents  
Year : 2019  |  Volume : 9  |  Issue : 1  |  Page : 25-27

Toothbrush bristles, a harbor of microbes and the risk of infection

1 Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
2 Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, USA
3 Cruz Davis Family and Cosmetic Dentistry, Gainesville Florida, USA

Date of Web Publication17-May-2019

Correspondence Address:
Mr. Philip Asumang
Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, P.M.B, Kumasi, Ashanti Region
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijohs.ijohs_60_18

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Microbes survive in a wide variety of environments, including toothbrush bristles regardless where they are kept once they are unsterilized. Toothbrush bristles serve unintentionally a great source of favorable condition for the growth and survival of microorganisms. Conducting a literature review of previous studies, we explored the microbial contamination of toothbrush bristles occurrence, and the risks this poses for disease infections in susceptible individuals in this review article.

Keywords: Contamination, environment, microbial infection, oral cavity, susceptible individual, toothbrush bristles

How to cite this article:
Asumang P, Inkabi SE, Inkabi S. Toothbrush bristles, a harbor of microbes and the risk of infection. Int J Oral Health Sci 2019;9:25-7

How to cite this URL:
Asumang P, Inkabi SE, Inkabi S. Toothbrush bristles, a harbor of microbes and the risk of infection. Int J Oral Health Sci [serial online] 2019 [cited 2023 Jun 7];9:25-7. Available from: https://www.ijohsjournal.org/text.asp?2019/9/1/25/258578

  Introduction Top

Oral hygiene is undoubtedly an essential practice for healthy living. There has been some type of cleaning instrument to clean and preserve teeth; although, the exact origin of these teeth cleaning devices is unknown. The early devices used in cleaning the teeth include the twig brush, tooth stick, also known as the toothpick, and plantain stalk with charcoal.[1] The historical forerunner of modern toothbrush could be the Babylonian fiber brush, called the “chew stick,” which was used as early as 3500 BC. It is a wooden stick cut to 5 or 6 inches in length with one-end macerated into bristle-like structures to about one-quarter of an inch.[1] Modern toothbrushes are used by both developing and developed countries for oral hygiene; nevertheless, chewing stick remains common to people in most urban and rural areas of developing countries to clean the teeth.[1],[2] The toothbrush is studied to be the most efficient tool for cleaning the teeth and tongue surfaces by removing oral biofilm and soft debris out of the mouth.[3] Previous studies have identified toothbrush bristles as the predominant retention hub of microorganisms, therefore, posing a reason for greater risk of bacterial infection and associated diseases.[4],[5] Microbial contamination of toothbrush bristles occurs after the initial use and increase of microbial load with repeated use.[6],[7],[8],[9] The microbes that contaminate toothbrush bristles originate from oral cavities, hands, and moist environment.[10]

This review seeks to evaluate and provide a comprehensive overview of microbial contamination of toothbrush bristles occurrence, and the risks this poses for disease infections in susceptible populations.

To extract relevant studies, systematic reviews of the peer-reviewed literature were conducted. The electronic databases utilized were PubMed Central and Google Scholar, to identify the published literature having the key search terms toothbrush, microbial infections, contamination, and other appropriate phrases relevant to the topic.

Microbes of pathogenic importance

Although there are insufficient studies on toothbrush bristles microbial contamination, the negative consequences of microbial contamination and growth on the toothbrushes bristles to the oral and systemic health have been established.[4] Microorganisms that studies have found to be of pathogenic importance in contaminating toothbrush bristles include Peptostreptococcus, Eubacterium species, Beta-hemolytic streptococci, Enterococci, Lactobacilli, Staphylococcus aureus, Serratia marcescens,  Escherichia More Details coli, Klebsiella spp., Enterobacter cloacae, Enterobacter aerogenes, Enterococcus faecalis, Candida albicans, Staphylococcus epidermidis, and Pseudomonas aeruginosa.[4],[11] With high microbial loads, stomatitis, dental caries, gingivitis, and infective endocarditis are diseases affecting both oral and general health in susceptible hosts, including older and immunocompromised individuals.[4],[12]

Microbial contamination of toothbrush bristles and the infection risks

A cross-sectional study carried out at the Hamdard University, Karachi, aimed at isolating the bacterial contaminants on used manual toothbrushes and to compare the type of bacterial growth in capped and uncapped toothbrushes determined that a substantial number of toothbrushes (85.8%) were found to have bacterial contamination, out of a total of 106 participants.[13] A significant correlation was observed (P < 0.05) between the presence of Klebsiella and Pseudomonas and uncapped toothbrushes, although other microbes, Enterococcus, Micrococcus, E. coli, Bacillus, and Streptococcus, were also isolated in both capped and uncapped toothbrushes.[13] In another cross-sectional studies involving 34 dentistry students as participants, Merino-Alado et al., isolated C. albicans, Candida krusei, Candida dubliniensis, and Candida glabrata from the new sterile toothbrush used by each of the participants for continuous 60-day period under a close survey evaluating their storage habits and the distance of the toothbrush from the toilet (in centimeters).[14]

Lee et al. in their studies evaluated the bacterial contamination of charcoal bristles compared to the noncharcoal bristles in used toothbrushes of ninety participants. It was determined although not statistically significant, the mean colony-forming units count for noncharcoal bristles toothbrush was almost double that of charcoal bristles toothbrush after 1 week of use, although charcoal toothbrushes are claimed to have antimicrobial properties due to the charcoal in the bristles that results in less bacterial contamination.[15],[16]

An in vivo study aimed at evaluating the viability of Streptococci mutans on toothbrushes bristles, and the production of extracellular polysaccharide related to drying time revealed that Mutans streptococci remained viable on toothbrush bristles for 44 h.[17] This study showed that, S. mutans found to be associated with used toothbrushes bristles, leave users at higher risk of acquiring various infections. Another study determined that, during orthodontic therapy with multi-bracket (MB) appliances, toothbrush bristles were contaminated more intensely with S. mutans regardless of the bristle design, and significantly higher on toothbrush bristles that were used by the MB-patients. This resulted in the high occurrence of caries and gingivitis in the MB-patients.[18]

A previous study evaluating the incidence of reported cases of dental caries, and periodontal disease was done involving families of 102 participants attending the dental clinics. The study determined that toothbrushes, particularly its bristles used by most participants during 1 month and apparently exposed to the bathroom environment, were heavily contaminated with Enterobacteriaceae and Pseudomonadaceae species.[19]

A recent study conducted involving 40 participants at the Faculty of Dentistry, Skopje, and data analyzed at the Institute for Microbiology and Parasitology, Faculty of Medicine in Skopje showed that, there was much bacterial load of E. coli, Klebsiella spp., E. cloacae, S. marcescens, and P. aeruginosa. This was determined after the first month of daily toothbrush use by the participants.[4]

Factors influencing toothbrush bristles microbial contamination

Environmental conditions have been delineated the dominant factor in the growth of microbes on toothbrush bristles. The studies carried out at dental clinics hypothesized that environmental factors pertaining to a short distance from the toilet, the toothbrush storage conditions, and the bathroom humidity influenced the growth of the microbes on the toothbrush.[19] Pesevska et al. studies also showed that 85% of the participants who stored toothbrushes in bathrooms with toilets had more pathogenic microbial contamination of the tooth bristles than the remaining 15% of participants who stored toothbrushes in bathrooms without toilets.[4] A study conducted in the intensive care unit (ICU) of a University teaching hospital explored environmental factors, including location, the distance of the toothbrush to the bathroom and sink, toothbrush storage containers, contact with other articles, and moisture that possibly related to toothbrush contamination.[20] It was established that potential pathogenic microbes, methicillin-resistant S. aureus, vancomycin-resistant Enterococcus spp., and Acinetobacter spp. in the ICU contaminated the toothbrushes, increasing the risk of infection in the patients.[20]

Although not many studies have been done evaluating the role of oral cavities in influencing microbial contamination of toothbrush bristles, there was an appreciable level of microbial contamination of toothbrush bristles after their usage in cleaning the teeth.[20] The oral cavity has been reported to have the highest concentration of different microbial populations.[21] Furthermore, the use of contaminated fingers in touching the toothbrush bristles before or after its usage plays a significant role in the microbial contamination of the toothbrush.[4]

  Conclusion Top

Oral hygiene recommendations such as more frequent, at least once a month, replacement of toothbrushes,[4],[18],[19] storing of toothbrushes adequately to avoid bristles contact, and away from the toilet to minimize bacterial contamination, therefore, reducing the risk of microbial transmission and translocation have been suggested.[19],[20] However, there is a greater risk of microbial infection to susceptible individuals having toothbrush playing a crucial role.

This review article highlights the microbial contamination of toothbrush bristles occurrence, and further provides the conceptualization of infection risks that users of a toothbrush are prone to. Although the limited research studies establish the presence of pathogenic microbes, by isolating them from toothbrush bristles, further studies should be done on characterizing the microbes isolated from toothbrush bristles and the oral and systemic diseases, these microbes cause to extend our understanding of the severity of the microbial contamination of toothbrush bristles.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Hyson JM Jr. History of the toothbrush. J Hist Dent 2003;51:73-80.  Back to cited text no. 1
Malik AS, Shaukat MS, Qureshi AA, Abdur R. Comparative effectiveness of chewing stick and toothbrush: A randomized clinical trial. N Am J Med Sci 2014;6:333-7.  Back to cited text no. 2
Beneduce C, Baxter KA, Bowman J, Haines M, Andreana S. Germicidal activity of antimicrobials and VIOlight personal travel toothbrush sanitizer: Anin vitro study. J Dent 2010;38:621-5.  Back to cited text no. 3
Pesevska S, Ivanovski K, Mindova S, Kaftandzieva A, Ristoska S, Stefanovska E, et al. Bacterial contamination of the toothbrushes. J Int Dent Med Res 2016;9:6.  Back to cited text no. 4
Mehta A, Sequeira PS, Bhat G. Bacterial contamination and decontamination of toothbrushes after use. N Y State Dent J 2007;73:20-2.  Back to cited text no. 5
Saravia ME, Nelson-Filho P, da Silva RA, Faria G, Rossi MA, Ito IY, et al. Viability of Streptococcus mutans toothbrush bristles. J Dent Child (Chic) 2008;75:29-32.  Back to cited text no. 6
Warren DP, Goldschmidt MC, Thompson MB, Adler-Storthz K, Keene HJ. The effects of toothpastes on the residual microbial contamination of toothbrushes. J Am Dent Assoc 2001;132:1241-5.  Back to cited text no. 7
Nelson-Filho P, Isper AR, Assed S, Faria G, Ito IY. Effect of triclosan dentifrice on toothbrush contamination. Pediatr Dent 2004;26:11-6.  Back to cited text no. 8
Bonten MJ, Hayden MK, Nathan C, van Voorhis J, Matushek M, Slaughter S, et al. Epidemiology of colonisation of patients and environment with vancomycin-resistant enterococci. Lancet 1996;348:1615-9.  Back to cited text no. 9
Caudry SD, Klitorinos A, Chan EC. Contaminated toothbrushes and their disinfection. J Can Dent Assoc 1995;61:511-6.  Back to cited text no. 10
Sammons RL, Kaur D, Neal P. Bacterial survival and biofilm formation on conventional and antibacterial toothbrushes. Biofilms 2004;1:123-30.  Back to cited text no. 11
Naik R, Ahmed Mujib BR, Telagi N, Anil BS, Spoorthi BR. Contaminated tooth brushes-potential threat to oral and general health. J Family Med Prim Care 2015;4:444-8.  Back to cited text no. 12
[PUBMED]  [Full text]  
Mansoori N, Bakar I, Shahid N, Mubeen SM. Microbial contamination; a survey of microbial contamination of toothbrushes among general population of Karachi. Prof Med J 2018;25:1785-90.  Back to cited text no. 13
Merino-Alado RL, Garcés A, Chianale E, Corcuera C, Fakih WE, Galviz D, et al. Isolation of fungi and gram-negative bacteria from toothbrushes and bathroom bioaerosols. Pesqui Bras Odontopediatria Clin Integr 2018;18:1-10.  Back to cited text no. 14
Lee J, Palaniappan K, Hwai TT, Kit CW, Dicksit DD, Kalyan CG, et al. Comparison of bacterial contamination in bristles of charcoal toothbrushes versus non-charcoal toothbrushes. Can J Dent Hyg 2017;51:69-74.  Back to cited text no. 15
Ramachandra SS, Dicksit DD, Gundavarapu KC. Oral health: Charcoal brushes. Br Dent J 2014;217:3.  Back to cited text no. 16
Assed Bezerra Da Silva L, Nelson-Filho P, Saravia ME, De Rossi A, Lucisano MP, Assed Bezerra Da Silva R, et al. Mutans streptococci remained viable on toothbrush bristles, in vivo, for 44 h. Int J Paediatr Dent 2014;24:367-72.  Back to cited text no. 17
Eichenauer J, von Bremen J, Ruf S. Microbial contamination of toothbrushes during treatment with multibracket appliances. Head Face Med 2014;10:43.  Back to cited text no. 18
Contreras A, Arce R, Botero JE, Jaramillo A, Betancourt M. Toothbrush contamination in family members. Rev Clín Periodoncia Implantol Rehabil Oral 2010;3:24-6.  Back to cited text no. 19
Frazelle MR. Healthcare Acquired Infection Risk and Toothbrush Contamination in the ICU. PhD Thesis. Virginia Commonwealth University, Richmond, Virginia; December, 2011.  Back to cited text no. 20
Kuboniwa M, Lamont RJ. Subgingival biofilm formation. Periodontol 2000 2010;52:38-52.  Back to cited text no. 21


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