|Year : 2016 | Volume
| Issue : 1 | Page : 10-16
Effectiveness of three different oral hygiene techniques on Viridans streptococci: A randomized controlled trial
N Naveen1, P Guru Suhas1, N Vanishree1, M Vinitha2, C Bharath1, M Anushri1
1 Department of Public Health Dentistry, Bangalore Institute of Dental Sciences, Bengaluru, Karnataka, India
2 Department of Microbiology, Bangalore Institute of Dental Sciences, Bengaluru, Karnataka, India
|Date of Web Publication||15-Mar-2016|
Department of Public Health Dentistry, Bangalore Institute of Dental Sciences, #5/3, Hosur Main Road, Lakkasandra, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
Introduction: Tongue cleaning is an important aspect of oral hygiene maintenance along with other mechanical and chemical aids. These methods have an influence on microorganism count in saliva. Aim: To assess the effectiveness of three different oral hygiene techniques on Viridans streptococci. Materials and Methods: This was a randomized controlled trial with 45 study subjects aged between 14 and 16 years and were randomly allocated into three groups: Group A - plastic tongue scraper, Group B - chlorhexidine mouthwash along with plastic tongue scraper, and Group C - chlorhexidine mouthwash. Unstimulated salivary samples were collected on the 1st, 7th, and 15th day before routine oral hygiene practices. Saliva samples were collected and incubated for 48 h on itis Salivarius(MS) agar. Streptococcus mitis, Streptococcus mutans, and Streptococcus salivarius were counted. Data were analyzed using descriptive and inferential statistics. Results: The mean count of S. mitis, S. mutans, and S. salivarius for Group A, B, and C was found to be significant (P < 0.001) when compared between 1st, 7th, and 15th day. Between-groups comparisons revealed a significant difference between Groups A and C, B and C (P < 0.001). Conclusion: There was a significant reduction in bacterial count in all the participants indicating that all the three methods are useful in improving oral hygiene. Combination technique was found to be most effective.
Keywords: Mouthwash, oral hygiene, saliva, tongue, Viridans streptococci
|How to cite this article:|
Naveen N, Suhas P G, Vanishree N, Vinitha M, Bharath C, Anushri M. Effectiveness of three different oral hygiene techniques on Viridans streptococci: A randomized controlled trial. J Indian Assoc Public Health Dent 2016;14:10-6
|How to cite this URL:|
Naveen N, Suhas P G, Vanishree N, Vinitha M, Bharath C, Anushri M. Effectiveness of three different oral hygiene techniques on Viridans streptococci: A randomized controlled trial. J Indian Assoc Public Health Dent [serial online] 2016 [cited 2020 Aug 14];14:10-6. Available from: http://www.jiaphd.org/text.asp?2016/14/1/10/178727
| Introduction|| |
The most common concept concerning individual health is the harmony of one's physical, mental and social well-being. The simple absence of disease is not accepted as an indication of health. Tongue cleaning being an ancient habit is practiced for centuries in many Eastern and Oriental cultures, though not very popular in the Western civilizations.
Dental caries is undoubtedly a multifactorial disease and dental plaque plays a major role in its pathogenesis. The pellicle, which is an organic bacteria-free film, deposits on the tooth surfaces within nanoseconds after vigorous tooth brushing or polishing. Then, the bacteria start to colonize the tooth surface. The dental plaque, in sufficient concentration, can disturb the host-parasite relationship and cause dental caries. The plaque thickness differs depending on the locally prevailing oral cleansing forces, oral hygiene, and other factors such as salivary components. The oral surfaces are colonized by over 500 bacterial species, and tongue has the largest bacterial load of any oral tissue and makes the greatest contribution to the bacteria found in the oral cavity.
Tongue coating, which mainly comprises bacteria, large amounts of desquamated epithelial cells released from the oral mucosa, leukocytes from periodontal pockets, and blood metabolites, is also an important factor for oral malodor production in both periodontally diseased and healthy people. The structure of the tongue, with its fissures and crypts, provides a large surface area for accumulation of oral debris and microorganisms. Hence, periodontal treatment and removal of tongue coating can be expected to improve oral malodor by reducing the number of periopathogens in oral malodor patients.
The tongue dorsum occupying a huge area of the oral mucosa can harbor microorganisms including periodontopathic bacteria in addition to oral streptococci. Furthermore, tongue mucosa is a major habitat of Candida species, which can cause severe infections in immunocompromised hosts such as patients in the preoperative period or bedridden elderly. More than 100 bacteria may be attached to a single epithelial cell on top of the tongue, whereas only about 25 bacteria are attached to each cell in other areas of the oral cavity. The most important species of the viridans group are Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Streptococcus oralis, and Streptococcus salivarius which are part of the normal flora. They are therefore referred to as oral streptococci. As pathogens, some species are involved in the genesis of infective endocarditis and dental caries.
Such microorganisms aggregate with mucosal epithelium detachment, as well as food and saliva components, and others, and cover the tongue surface to form the so-called tongue coating. It has been reported that detection rates of periodontopathic bacteria in tongue coating were closely associated with those in dental plaque. Furthermore, following the loss of all natural teeth, there is a decreased prevalence of selective periodontopathic bacteria on the tongue. In addition, during periods of refraining from oral hygiene, periodontopathic bacteria in the tongue coating increase along with the accumulation. Based on those findings, it is considered that tongue coating and dental plaque have a reservoir and acceptor relationship to share oral microorganisms and likely that tongue cleaning has some effect on plaque formation.,
Studies ,,, have also found a significant correlation between the prevalence of S. mutans in saliva and its prevalence on the dorsum of the tongue. Tooth brushing alone is effective in reducing bacterial counts in the mouth but not dramatically. Tongue cleaning seems to have a more dramatic effect on the salivary levels of caries-causing bacteria such as S. mutans. With tongue scraping becoming established as an excellent tool for reducing the levels of S. mutans in the oral cavity, it would be of great interest to compare the effectiveness of tongue brushing method for decreasing the bacterial count in the oral cavity and chlorhexidine has proved to be efficient in reduction of microbial load.
Tongue cleaning can be done in many ways by the use of various aids such as tongue cleaners, soft-bristled brushes, and mouthwash or by a combination of these. These methods have a significant influence on the Streptococcus viridans count. Thus, this study aims to compare the effect of tongue scrapers, mouthwash individually, and their combination on S. viridans count.
- To assess the effect of tongue scraping on Viridans streptococci count among the study subjects
- To assess the effect of mouthwash on V. streptococci count among the study subjects
- To assess the effect of combination technique on V. streptococci count among the study subjects.
| Materials and Methods|| |
This was a randomized clinical trial with three parallel arms to test the effectiveness of three different oral hygiene techniques on V. streptococci. Study subjects in the age group of 14–16 years residing in a residential/institutional setup were considered for the study. Residential/institutionalized center is considered for the study as it becomes easier to monitor them during their oral hygiene practices, to collect the saliva sample and there will be not much of change in their dietary intake. Ethical clearance was obtained from the Institutional Ethical Committee. Necessary permission was obtained from the respective institution authorities, and verbal consent was taken from all the study participants. The institution authorities and the study participants were explained about the procedure along with the possible risks and benefits that would occur.
Before starting the study, the training and calibration of the examiner were done, and kappa value was found to be 0.83. A pilot study was conducted by collecting the saliva samples from 5 participants to check for the growth of microorganisms and feasibility of the procedure. These study participants were exempted from the final analysis.
- Study subjects with all the permanent teeth erupted in the age group of 14–16 years
- Study subjects who gave informed consent to participate in the study
- Institution/Institutions which has given permission to conduct the study
- Study participants who are not using tongue scrapers/mouthwash/combination.
- Study subjects with systemic diseases and on medication
- Study subjects who are known to be allergic to mouthwash.
The sample size estimation was done based on the literature available from previous studies  and accordingly 45 subjects will be considered for the study. Based on eligibility criteria by convenience sampling technique a total of 45 subjects from children home for boys were considered for the study. These 45 subjects were randomly allocated into three groups (Group A, Group B, and Group C) by lottery method with 15 subjects in each group by a person who was not part of the study and also not aware of the objectives of the study. The random concealment of the materials used for the study was done before the start of the study. Each study subject was assigned a number, and accordingly corresponding number was stuck to the tongue scraper/mouthwash pertaining to the group he belonged.
Group A was given a plastic tongue scraper. Group B was given a combination of mouthwash and plastic tongue scraper. Group C was given mouthwash. The study participants were instructed not to change any of their oral hygiene practices.
This group involved 15 participants who constituted the tongue-scraping group. Participants were given a plastic tongue scraper and asked to scrape the dorsum of the tongue once daily. The tongue scraper used in this study was an inverted “V” shaped.
The following instructions were given:
- Place the tongue as far out of the mouth as possible and place the tongue scraper as far posterior as possible on the tongue (comfortable enough to avoid gagging)
- Apply force on the scraper to flatten the tongue, making it conform to the surface of the tongue and pull the scraper forward slowly but firmly up to the tip of the tongue
- Spit out the excess saliva and\or debris that accumulates on the tongue and removes the debris from the tongue scraper by placing it under a stream of running water
- Once the procedure was completed, the study participants were instructed to clean them and were informed to hand it over to the investigator. This was done to avoid any exchange or over usage of the intervention aid.
This group involved 15 participants who were given both tongue scraper and hexidine mouthwash containing 0.2% w/v of chlorhexidine gluconate. Study participants of this group were first asked to clean the dorsum of the tongue with plastic tongue scraper. After this, 10 ml of hexidine mouthwash was diluted with equal amount of water and given to each participant. They were asked to swish the mouthwash for 30 s and spit. Participants were instructed not to swallow the mouthwash and not to eat or drink anything for 30 min.
This group involved 15 participants who were given hexidine mouthwash.
Ten milliliter of hexidine mouthwash was diluted with equal amount of water and given to each participant. They were asked to swish the mouthwash for 30 s and spit. Participants were instructed not to swallow the mouthwash and not to eat or drink anything for 30 min.
Method of collection of salivary samples
Before the start of the study, all the study participants were given a brief outline of the procedure that they had to follow during the study period. Since it was a residential home, all the study participants were having a similar type of diet. Study participants were given a 10 ml sterile container to collect the saliva sample. The investigator collected the saliva sample from the study participants in the morning after the study participants had brushed their teeth (baseline). Unstimulated salivary samples were collected in the test tube by spitting method from all subjects before the start of the experiment to establish baseline V. streptococci level. All the study participants were monitored by the investigator every day to perform their respective procedures. Unstimulated salivary samples were collected from all the participants at three different intervals, i.e., 1st, 7th, and 15th day.
Processing of saliva samples
About 1 ml saliva samples were collected in a 10 ml sterile container and were immediately transported to the Department of Microbiology. Since the saliva samples were transported within 20 min after collection to the laboratory transport media were not used. Mitis Salivarius agar plates were procured from HiMedia laboratories. The saliva samples collected were streaked on MS agar plate using an inoculating loop of 4 mm diameter which will carry a 0.01 ml of saliva. Streak plate method  was used to streak the saliva samples on the agar plate. Three streaks were made on each agar plate, i.e., primary streak, secondary streak, and tertiary streak. Agar plate was incubated at 37°C for 48 h and counted for microorganisms based on the morphology and characteristics of the colony forming units.
Identification of microorganisms
S. salivarius uses sugars to produce a gummy-like levan producing sticky, mucoid, and gum drop colonies which are large light blue. S. mitis are small, flat, light blue pinpoint colonies, and S. mutans are medium-sized dark blue undule-shaped colonies with a granular frosted glass appearance colonies formed on the agar plate were counted using viable count method.,
Statistical significance was set at P < 0.05. The data were compiled and analyzed using SPSS (version 21; SPSS Inc., Chicago, IL, USA). Descriptive statistics were done for all the groups. Repeated measure ANOVA was used to test the difference within the group, and ANOVA was used to check the difference between the groups.
| Results|| |
A total of 45 children aged between 14 and 16 years participated in the study. Sample characteristics of the study participants are presented in [Table 1].
The mean reduction in mitis count among the study participants was measured at day 1st, 7th, and 15th day. The mean reduction in mitis count of all the group participants who performed different oral hygiene techniques was found to be statistically significant (P < 0.0001) [Table 2].
|Table 2: Mean reduction in mitis count among study participants (CFU/ml)|
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The mean reduction in mutans count among the study participants were measured at day 1st,7th, and 15th day and was found to be statistically significant (P < 0.0001) [Table 3].
|Table 3: Mean reduction in mutans count among study participants (CFU/ml)|
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The mean reduction in salivarius count among the study participants was measured at day 1st, 7th, and 15th day. The mean reduction in salivarius count of all the group participants who performed different oral hygiene techniques was found to be statistically significant (P < 0.0001) [Table 4].
|Table 4: Mean reduction in salivarius count among study participants (CFU/ml)|
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Between groups comparisons revealed a significant difference in mutans and salivarius count among the study participants, whereas mitis count was not significant [Table 5].
|Table 5: Intergroup comparison of Viridans streptococci for the study duration (post hoc)|
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| Discussion|| |
This clinical trial investigated the effectiveness of three different oral hygiene techniques on V. streptococci. A total of 60 children aged between 15 and 16 years satisfying inclusion and exclusion criteria were selected for the study. A total of 45 students were randomly selected from this group and were randomly allocated to three different groups Group A, Group B, and Group C, which was in line with previous study conducted by Rupesh et al. All the participants of three groups were given three different modes of intervention. Since it was a residential home, there were no losses due to follow-up. As diet was controlled in our study, the three different tongue cleaning interventions were possibly given the best chance of demonstrating their efficacy against V. streptococci.
Tongue microflora projects, a bacterial population that contains on average 29% Streptococci, 48% Gram-negative anaerobes, and 2.5% with an H2S-producing phenotype. Studies have proved effective tongue cleaning along with routine oral hygiene practices would decrease halitosis by reducing the hydrogen sulfide and other volatile compounds that are produced by various microorganisms which were proved in a study conducted by Ciçek et al.
Further clinical trials were done to know the impact of cleaning the tongue on microbial load, i.e. both aerobic and anaerobic microorganisms which revealed that tongue cleaning would decrease the microbial load on the tongue and also improve the taste sensation.
Dental caries is the most common oral disease with high prevalence, as proven it is multifactorial in etiology caused due to interaction between agent host and environment factors. Microorganisms contribute to the causation of dental caries under suitable conditions. Among the various microorganisms inhabiting the oral cavity Streptococci contribute the main group of organisms involved in the initiation of dental caries. There have been a wide plethora of preventive strategies to prevent this disease. Tongue cleaning is also one of the effective measures in decreasing microbial count from the dorsum of the tongue; hence, our study investigated the effectiveness of different oral hygiene techniques on V. streptococci inhabiting the oral cavity.
In this regard, our study was the first to compare different tongue cleaning techniques, i.e., tongue scraping using plastic tongue cleaner, mouthwash, and combination of both.
The results revealed that all the three techniques used showed a statistically significant difference in reduction of salivary V. streptococci.
Study participants in our study group had an age range between 14 and 16 years and were boys which was in line to the study conducted by Rupesh et al. and Gondhalekar et al., on the other hand, White et al. carried out similar study in elderly individuals.
Study participants who were given tongue scraper showed a gradual decrease in mitis, mutans, and salivarius count and the results were found to be statistically significant. Similar results were obtained by the studies conducted by Almas et al. in the year 2005 and Rupesh et al. in the year 2012 and White et al. in the year 2004, wherein they found a significant decrease in mutans level. This may be due to effective removal of the coating present on the tongue which acts as a harbor for retention of the food leading to increase in a number of microorganisms. Contrarily, Menon and Coykendall  reported small changes in microbial counts upon tongue scraping which were not statistically significant, this could be because of the duration of the study as they conducted only for 1 day. Gilmore and Bhaskar  in the year 1972 conducted one of the first studies involving tongue cleaning. They found that tongue brushing on a daily basis decreased the bacterial populations on the tongue. The study however focused on S. salivarius levels. Studies done by Casemiro et al., Bordas et al., Gulati and Gupta  proved the positive association of tongue cleaning and reduction in the microbial count and also established the importance of mechanical cleaning of the tongue.
Study participants who were given only mouthwash showed a gradual reduction in the microbial count and the results were found to be statistically significant. Similar results were obtained by the studies conducted by Agarwal et al. in the year 2012, this might be due to the bacteriostatic action of the mouthwash on the oral microflora. De Boever and Loesche  in the year 1995 found 74% bacterial reduction on the use of chlorhexidine (both as rinse and as paste).
Another group of study participants, i.e., Group B were given combination of tongue scraper and mouthwash revealed a significance decrease in microbial count from baseline (1st day) and 15th day. This may be due to the synergistic action, i.e., both mechanical and chemical action of tongue scraper and mouthwash on the oral microflora. Post hoc analysis revealed a significant decrease in the microbial count in Group B when compared to other groups implying the effectiveness of the combination technique. De Boever and Loesche  reported tongue cleaning combined with the use of chlorhexidine rinse and paste, which explains the possibility of 74% bacterial reduction on the tongue due to combined mechanical and chemical methods.
The oral hygiene measures used in our study were simple, could be carried out fast and the benefits for most children. Furthermore, none of the participants had any compliance problems, aberrations, lesions, etc., anytime during the study after using either the scraper or the mouthwash. Our study was a novel attempt designed to simulate a realistic home regimen in which the subjects either performed tongue scraping or using mouthwash daily while continuing their normal tooth brushing routine. In this context, it is to be noted that the reductions in salivary V. streptococci in our study occurred in addition to the effects of tooth brushing.
- Preventive measures need to include an effective means of reducing the pool of V. streptococci inhabiting the dorsum of the tongue if one is to truly expect a reduction in caries and halitosis.
- Future research involving the long-term evaluation of tongue cleaning-related outcomes in different types of populations are needed.
- A major limitation of our study was the duration of the study, we could only check for the short-term effects of the intervention; further studies are required to check long-term effects of these oral hygiene aids on the microbial count.
| Conclusion|| |
This study was a novel approach to test three different oral hygiene techniques in the reduction of microbial load, especially V. streptococci. This study revealed that all the three oral hygiene techniques were effective in decreasing the microbial load, and the combination technique was more effective as it is a result of mechanical and chemical actions on the microorganisms.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]