|Year : 2010 | Volume
| Issue : 3 | Page : 162-166
Comparative evaluation of the efficacy of different concentrations of chlorhexidine mouth rinses in reducing the mutants streptococci in saliva: An in vivo study
R Jayaprakash1, A Sharma2, J Moses2
1 Former Postgraduate Student, Department of Pedodontics and Preventive Dentistry, Saveetha University, Chennai, Tamilnadu, India
2 Professor and Head of the Department, Department of Pedodontics and Preventive Dentistry, Saveetha University, Chennai, Tamilnadu, India
|Date of Web Publication||11-Dec-2010|
Old No. 116, New No. 66, Perambur High Road, Perambur Jamalia, Chennai - 600 012
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Is low-concentration chlorhexidine effective against reducing the mutans streptococci (MS) in saliva? Aim: To compare the efficacy of different concentrations of chlorhexidine mouth rinses, i.e. 0.02%, 0.06% and 0.12%, in reducing the mutants streptococci count in saliva. Design: Forty subjects in the age group of 12-14 years were selected from the schools of Chennai and were equally divided into four groups. The first three were study groups and the fourth group was the control group. The subjects were instructed to rinse with a measured amount of mouth rinse for 1 min, twice-daily, for 1 week. Salivary samples were collected at baseline and 1 week after mouth rinsing with various concentrations and were cultured on MSB agar. The number of MS colonies was counted on agar medium under anaerobic conditions. Results: The results of the study confirmed that children using chlorhexidine of concentration 0.12% showed the maximum reduction in MS when compared with subjects using 0.02% and 0.06% concentrations. But, children using chlorhexidine of concentration 0.06% also showed significant reduction in MS when compared with the control group. Conclusion: From the above study, we conclude that chlorhexidine used in different concentrations (0.02%, 0.06%, 0.12%) efficiently reduced the mutans count.
Keywords: Chlorhexidine, microbial study, mutans streptococci, salivary test
|How to cite this article:|
Jayaprakash R, Sharma A, Moses J. Comparative evaluation of the efficacy of different concentrations of chlorhexidine mouth rinses in reducing the mutants streptococci in saliva: An in vivo study. J Indian Soc Pedod Prev Dent 2010;28:162-6
|How to cite this URL:|
Jayaprakash R, Sharma A, Moses J. Comparative evaluation of the efficacy of different concentrations of chlorhexidine mouth rinses in reducing the mutants streptococci in saliva: An in vivo study. J Indian Soc Pedod Prev Dent [serial online] 2010 [cited 2020 Jul 16];28:162-6. Available from: http://www.jisppd.com/text.asp?2010/28/3/162/73792
| Introduction|| |
Dental caries is an infectious disease that occurs because of an imbalance in the homeostasis between host and oral flora. This imbalance is created by the emergence of cariogenic microorganisms in the complex community known as dental biofilm.
Of all microorganisms, mutans streptococci (MS) are most closely associated with the development of dental caries disease. , They may cause mineral loss due to their characteristic capacities to adhere to the dental surface, to rapidly transport fermentable carbohydrates and convert them into acid, to produce extra- and intracellular polysaccharides and to maintain carbohydrate metabolism in a low pH (acid-tolerant) medium. , The presence of MS in dental biofilm has been used as an indicator of cariogenic biofilm.
Reducing their levels in the oral cavity will provide additional rationale for the prevention of dental caries. There are many studies in which chlorhexidine mouth rinses have been used in relation to plaque inhibition and plaque growth. ,,,
Limited information is available regarding comparison of the various concentrations of chlorhexidine mouth rinses. Hence, the study was designed and carried out with the aim to compare the efficacy of various concentrations of chlorhexidine mouth rinses.
| Aim and Objectives|| |
The primary objective of this study is to compare the efficacy of different concentrations of chlorhexidine mouth rinses, i.e. 0.02%, 0.06% and 0.12%, in reducing the MS count in saliva.
| Materials and Methods|| |
Sixty subjects in the age group of 12-14 years were selected from the schools of Chennai. After taking parental consent, they were screened for high caries risk group in accordance with DCC criteria (well-defined clinical criteria). 
Well-defined clinical criteria
Subjects with at least one active white spot on smooth surfaces (facial or lingual) was considered a high caries activity subject. The presence of the active lesions on these surfaces and a high caries activity imply that the subject has a high infection of MS, which means that he/she belongs to the high caries risk group.
Prior dental caries experiences were also checked, in which the subject may or may not have restorations, arrested caries lesions, extracted teeth, carious cavities and secondary caries.
Exclusion criteria during subject selection were:
Subjects were assigned with toothpaste containing no antimicrobial agents and instructed to brush twice daily. A 1-week wash out period was given.
- Physical limitations, which might preclude normal tooth brushing and mouth rinsing.
- Marked intraoral soft tissue pathology.
- Medically compromised patients and subjects with history of intake of antibiotics 3 months prior to or during the course of the study.
- Subjects undergoing orthodontic treatment.
- Subjects with extensive intraoral prosthesis.
Midmorning salivary samples were collected from the subjects, the saliva was stimulated by having the subject chew an inert paraffin wax for 2 min and whole stimulated saliva was collected into a sterile container. These salivary samples were processed for the growth of MS.
The salivary samples were diluted in 0.05 M phosphate buffer (pH 7.0) to dilutions of 10 -2 and 10 -3 and agitated for 30 s on a vortex mixer. For the cultivation of MS, 50 ml of the dilution was inoculated on MSB agar medium. The agar plates were incubated anaerobically in an anaerobic jar (5% CO 2 and 95% N 2 ) at 37°C for 48 h. The MS colonies were identified on the MSB agar plate by their typical colonial morphology  (crusted glass appearance). The number of MS colony forming units (CFU) per milliliter of saliva was estimated.
Finally, 40 subjects having more than 10 5 MS CFU per milliliter of saliva were selected and equally divided into the following four groups:
Group 1: Chlorhexidine mouth rinse (0.02%)
Group 2: Chlorhexidine mouth rinse (0.06%)
Group 3: Chlorhexidine mouth rinse (0.12%)
Group 4: Placebo mouth rinse (control group)
Along with the mouth rinse, individual measures were provided: 15 ml measures for chlorhexidine mouth rinse for 1 min, twice-daily, 30 min after the tooth brushing.  The subjects assigned mouth rinses were supplemented at 5-day intervals till completion of the study. After 2 weeks of treatment, the stimulated midmorning salivary samples were collected and processed for the growth of MS  [Figure 1],[Figure 2],[Figure 3],[Figure 4]. The obtained values were tabulated and subjected to statistical analysis.
Mean and standard deviation were estimated in each study group for pre, post and change.
The mean values were compared between pre- and post-rinse in each study group using Student's paired t-test.
One-way ANOVA followed by the Tukey-HSD procedure was used to compare the mean values among the different study groups.
In the present study, P < 0.05 was considered as the level of significance [Table 1] and [Table 2], [Figure 5] and [Figure 6].
|Table 2 :Comparison of mean values among different study groups at various time points |
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|Figure 6 :Mean change between pre- and post-rinse values in the different study groups|
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Analysis and interpretation
At the base line all the groups did not differ significantly from each other with respect to the total number of mutans streptococci CFU/MLOF saliva. One week after, treatment schedule there was a significant reduction in the mutans streptococci counts in the test groups than the control groups. Children using Chlorhexidine 0.12 concentration showed maximum reduction mutans streptococci when compared to subjects using 0.02% and 0.06% concentration. But 0.02 and 0.06 showed significant reduction in mutans streptococci when compared to the control groups
| Discussion|| |
Chlorhexidine is a potent antimicrobial agent, particularly against MS. Chlorhexidine affects the metabolic activity of bacteria because, in low concentrations, it is bacteriostatic and prompts both changes to the functioning of the cellular membrane as well as leakage of the intracellular constituents, ,,, while in high concentrations, it acts as a bactericide, prompting irreversible precipitation of the cellular contents. It, likewise, inhibits the action of the glycosyltransferase enzyme responsible for the accumulation of bacteria on the dental surface and has effects on sugar transport and acid production in oral bacteria.
Although it has potential antimicrobial activities, various side-effects such as staining, taste disturbances, desquamation and soreness of the oral mucosa have been reported (Fardall and Turnbull, 1986). 
Therefore, by reducing the concentration, the side-effects can also be reduced. From this study, the low concentration of chlorhexidine 0.02% and 0.06% showed significant reduction compared with the control groups. This adds observation to earlier studies performed by Jenkins  Helina  and Rubins.  It is widely believed that the combination of mechanical and chemical oral hygiene offers the greatest efficacy because the bulk of the plaque is reduced mechanically, leaving behind only disorganized and thin dental plaque, which can easily be reduced by chemical means.
Thus, by reducing the concentration of chlorhexidine, the bitter taste sensation is also reduced, making it more acceptable to children.
| Conclusion|| |
To conclude, judicious use of chlorhexidine, depending on the clinical situation, will provide better reduction of MS counts and, hence, dental caries.
What this paper adds
- Low concentrations of chlorhexidine are also effective against MS.
- By decreasing the concentration, the side-effects of chlorhexidine, such as taste disturbances and staining, can also be reduced.
Why this paper is important to pediatric dentists
- By reducing the concentration of chlorhexidine, the bitter taste sensation is also reduced, making it more acceptable to the pediatric population.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1], [Table 2]
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