Microbial contamination of tooth brushes and their decontamination

Transcription

1 ISSN Microbial contamination of tooth brushes and their decontamination BHAT S S a, HEGDE K S b, GEORGE R M C ABSTRACT With the dawn of the new century, dentistry: has seen a new face in the fields of diagnosis, treatment and prevention. Twenty one children were asked to brush their teeth for five days. The brushes were put in Robertson's Cooked Meat broth and cultured. Growth of Streptococcus Mutans were seen. These brushes were then placed in disinfectants such as 0.2% chlorhexidine gluconate ( Gp I), 1% sodium hypochlorite (Gp II) and water ( Gp III) for 24hrs and then cultured. Disappearance of growth of microorganisms was seen in Gp I and Gp II and remnants of growth seen in Gp III. It can be concluded that the use of disinfectant is a must for every individual at regular intervals. Keywords: Contamination, Disinfectant, Toothbrush INTRODUCTION With the dawn of the21 st century, dentistry has seen a new face in the arena of diagnosis, treatment and prevention. Diagnodent, air abrasion and dental caries vaccine have all proved effective aids in their respective fields. But we do have to ponder in the flaws of our age old method of primary prevention by tooth brushing. Oral hygiene was in practice as early as 3000 B.C. by the Sumerians 1. The medical work of ancient India suggest that the Charaka Samhita has numerous descriptions of toothbrushing and oral hygiene. The stick used for toothbrushing should be either astringent, pungent or bitter. One of its ends should be chewed in the form of a brush. It should be used twice a day, taking care that the gums not be injured Later, in India itself people cleaned their teeth with a primitive frayed stick called "Dantashakti" as prescribed by Sushruta. Cleaning was also done with betel leaves, camphor, cardamom etc. 2 The Mohammedans, as advocated by their Prophet, cleaned their teeth with " Meswak", a twig of Salvadora persica tree whose wood contained sodium bicarbonate and tannic acid and other astringents that have beneficial effect on the gums. The Arabians recommended rubbing teeth with powder of a. Professor and Head b. Associate Professor c. Post Graduate Student, Department of Pedodontics and Preventive Dentistry, Yenepoya Dental College, Mangalore. gull nut and pepper. The Chinese were among the earliest people to use the "Chewstick" made of plant limbs or roots with one end beaten into a soft fibrous condition used for scrubbing and brushing the teeth. These are still used by Asiatic and African people in the underdeveloped region. The bristle toothbrush appeared about the year 1600 in China as an instrument with bone handle into which horse hair bristles was inserted 3. In 1746, Pierre Fauchard felt that brushes was destructive to tissues and advocated washing teeth with sponges dipped in water or alcohol. In the 18 th century the bristles were made of hog hair. The Americans patented toothbrushes in In 1938, brushes were made of nylon bristles thus evolving into a variety of form and shape. 4 Studies have shown that toothbrushes are colonized by the oral microbiota which act as a reservoir to reintroduce microorganisms especially mutans streptococci or contaminate uninfected surfaces. Under usual conditions of storage, toothbrushes can be a vector for the transmission or reinfection of certain viruses such as HSV-I. 5 The present study was carried out to evaluate the presence of microorganisms in the toothbrushes and the effect of disinfectant such as chlorhexidine gluconate or sodium hypochlorite to decontaminate them. MATERIALS AND METHOD Twenty one children in the age group of 5 to 12 years were randomly selected for the present study, ethical clearance was taken prior to the commencement of study. Subjects with history of taking antibiotics 3 months prior to the study and subjects undergoing orthodontic treatment or with extensive intraoral prosthesis were excluded from the study. Dental hygiene instructions were explained to all the subjects after which each of them were given a toothbrush and paste. The children were subjected to supervised brushing using Fone's technique, once daily for five consecutive days. At the end of five days, toothbrushes were retrieved from them and were kept in test tubes containing Robertson's Cooked Meat Broth (Fig 1). Two used brushes were taken as positive control I and II (Fig 2). After immersing the brushes for about 4-5 hrs the broth was cultured on Mitis Salivarius Agar plates J Indian Soc Pedo Prev Dent September (2003) 21 (3)

2 J Indian Soc Pedo Prev Dent September (2003) 21 (3) 109 Microbial contamination of toothbrushes and their decontamination Fig 1 : Contaminated tooth brushes stored in Robertson's Cooked Meat Broth Fig 2 : Positive control tooth brushes stored in Robertson's Cooked Meat Broth Figs 3 & 4 : Colonies of mutans streptococci on mitis salivarius agar plates Fig 5 : Tooth brushes immersed in disinfectants, Group I in 0.2% chlorhexidine, Group II in 1% sodium hypochlorite and Group III in water

3 Fig 6 : Tooth brushes immeresed in disinfectants, Positive control I in 0.2% chlorhexidine, Positive control II in 1% sodium hypochlorite Fig 7 : No growth of mutans streptococci colonies after antimicrobial treatment in Group I Fig 8 : No growth of mutans streptococci colonies after antimicrobial treatment in Group II Fig 9 : No growth of mutans streptococci colonies after antimicrobial treatment in positive control I Fig 10 : No growth of mutans streptococci colonies after antimicrobial treatment in positive control II Fig 11 : Growth of mutans streptococci colonies after tooh brushes stored in Water J Indian Soc Pedo Prev Dent September (2003) 21 (3) 110

4 Graph 1 : Percentage of reduction of mutans streptococci colonies amongst the test and control groups and incubated for 48hrs. After incubation the growth of MS colonies were seen on all the twenty one agar plates including positive control I and II (Fig 3 & 4). These brushes were then immersed in disinfectants, 7 brushes in 0.2% chlorhexidine gluconate [Group I], 7 in 1% sodium hypochlorite [Group II] and 7 in water [Group III] (Fig 5). Positive control I was immersed in Group I and positive control II in Group II (Fig 6). After 24hrs, these brushes were again placed in Robertson Cooked Meat Broth and then cultured. The obtained data was subjected to statistical analysis. STATISTICS Statistical analysis was carried out using Wilcoxon Signed Rank Test. RESULTS Disappearance of all the mutans strptococci colonies was seen in the plates of Group I (Fig 7 ) and Group II (Fig 8) including positive control I and II (Fig 9 & 10). Colonies of mutans streptococci were seen in Group III (Fig 11). Treatment of tooth brushes with chlorhexidine have shown 100% reduction of mutans streptococci colonies and treatment of tooth brushes with sodium hypochlorite resulted in 98% reduction of mutans streptococci colonies, both the values are statistically highly significant (Graph 1). Tooth brushes stored in water have given 30% reduction in mutans streptococci colonies, which was statistically non significant (Graph 1). DISCUSSION A great variety of microbes such as Streptococcus, Nisseria, Candida infect the oral cavity in the very first day of life itself. 6 However, mutans streptococci the main etiological agent of dental caries in humans infect the oral cavity only after the eruption of teeth. Cobb CM. et al has reported that toothbrush is a major cause of repeated infection in the mouth 7. Svanberg M. found that toothbrushes could be heavily infected with microorganisms especially mutans streptococci within 24hrs of use 8. J Indian Soc Pedo Prev Dent September (2003) 21 (3) 111

5 Transmission can occur directly through saliva or indirectly through the use of fomites such as cups, spoons, or toothbrushes. It can be transmitted inter or intra individually which increases the incidence of dental caries especially in children 9. Toothbrushes play a major role in retention or retrieval of microorganisms. It poses a threat to certain patients at risk. Studies have shown that in subjects harbouring high number of Actinobacillus actinomycetemcomitans in the sub and supra gingival plaque, contaminated toothbrushes can lead to bacteremia. 10 It is seen that improperly cleaned or rinsed toothbrushes act as a factor for the growth of group A haemolytic streptococci which causes pharyngitis or tonsillitis in children 11. Dayoub M.B. et al stated that wet environment is an ideal factor for the growth of microorganisms and the use of a disinfectant is a must at regular intervals. 12 In spite of millions of toothbrushes sold through out the world each year, there is very little public awareness that the bristles can be contaminated with use. Jarvinen and Tenoron J. have stated chlorhexidine gluconate to be an ideal disinfectant. 13 Briseno B.M. has reported sodium hypochlorite to be an effective disinfectant. 14 Yokosuka N. et al has reported the innovation of chlorhexidinecoated bristle toothbrushes to be an effective method of prevention of bacterial contamination. 15 A.D.A in 1996 has recommended the change of toothbrushes after every three months. 16 Glass R.T. and Denny F.W. have advised the change of brushes after every three days for patients undergoing chemotherapy. 17,18 Those subjected to major surgery are to change brushes everyday and those sick should change brushes at the beginning of illness, when they first feel better and when they are completely well. It is seen that toothbrushes can act as a carrier of infection in the oral cavity. Thus, it is mandatory for every individual to disinfect his brush at regular intervals thereby maintaining a good oral hygiene. REFERENCES 1. Griffiths M.: Dentifrices as referred in "Mechanical and Chemical supragingival plaque control". Periodontology 2000; 8: Prabhu S.R.: Oral diseases in the tropics. 8th Edn.(1993) Oxford Medical Publication : John RMC Delland: Oral hygiene through the ages, teeth and health. June 1972,Vol 1 (2).As cited in Dentistry. An illustrated history. Malvin E. R., Harry N. A., INC Publishers, New York, Norman O. H., Arden G. C: Primary Preventive Dentistry 1996, 4th Edn. Chapter 5 : Glass R.T.: The infected toothbrush, the infected denture and transmission of disease. Compend Contin Educ Dent 1992; 8 : McCarthy C, Snyder M.L., Parker R.B.: The indigenous flora of man-the new born to the 1 year old infant. Arch Oral Biol 1965; 10 : Cobb C. M.: Toothbrush as a cause of repeated infections of the mouth. Boston M & SJ 1920; 183 : Svanberg M.: Contamination of toothpaste and toothbrush by Streptococcus mutans. Scan J Dent Res 1978; 86 : Newbrun E.: Preventing dental caries - Breaking the chain of transmission. J Am Dent Assoc 1992; 123 : Muller H.P., Lange D.P., Muller R.F. J Clin Periodontol 1989; 16: Brook, Alan E., Gober.: Arch Otolaryngol Head Neck Surg 1998; 124 : Dayoub M.B., Rusilko D., Gross A. : Microbial contamination of toothbrushes. J Dent Res 1977; 56 : Jarvinen,Tenoron J., Huovinen: In vitro susceptibility to chlorhexidine and six other antimicrobial agents. Abs.Medline (R) Anti microb agents chemotherapy 1993; 37 : Briseno B.M., Writh R., Standhartinger W.: Efficacy of different irrigation methods and concentration of R.C.T irrigation solution on bacteria in root canal. Endod.Dent.Traumatol 1992; 8: Yokosuka N., Tanaka T, Ebisudani K., Iwai T: Nippon Shishubyo Gakkai Kaishi 1989; 31: Meier S., Collier C, Scaletta M.G., Stephens J.: An in vitro investigation of the efficacy of CPC for the use in toothbrushes decontamination J Dent Hyg 1996; 70 : Glass R. T., Jenson H. G.: More on contaminated toothbrushes : the viral story. Quint Int 1988; 19 : Denny F. W.: Risk of toothbrushes in the transmission of respiratory infections. Paed Infect Dis 1991; 10 : Reprint Requests to: Dr. Sham S. Bhat, Professor and Head, Department of Pedodontics and preventive Dentistry, Yenepoya Dental College, Mangalore Karnataka. J Indian Soc Pedo Prev Dent September (2003) 21 (3) 112