|Year : 2008 | Volume
| Issue : 5 | Page : 14-18
The effect of povidone-iodine and chlorhexidine mouth rinses on plaque Streptococcus mutans count in 6- to 12-year-old school children: An in vivo study
R Neeraja1, A Anantharaj1, P Praveen1, V Karthik1, M Vinitha2
1 Department of Pedodontics and Preventive Dentistry, R.V Dental College, Bangalore, Karnataka, India
2 Department of Microbiology, R.V Dental College and Hospital, Bangalore, Karnataka, India
Department of Pedodontics and Preventive Dentistry, M.R Ambedkar Dental College,1/36, Cline Road, Cooke Town, Bangalore - 560 005, Karnataka
| Abstract|| |
Objectives: Treating a carious tooth in children with high caries experience by providing a restoration does not cure the disease. If the unfavorable oral environment that caused the cavity persists so will the disease and more restorations will be required in future. Treating the oral infection by reducing the number of cariogenic microorganisms and establishing a favorable oral environment to promote predominantly remineralization of tooth structure over time will stop the caries process.
The present study was conducted:
(1) To evaluate the efficacy of povidone-iodine and chlorhexidine mouth rinses on plaque Streptococcus mutans when used as an adjunct to restoration.
(2) To compare the anti-microbial effect of 1% povidone-iodine and 0.2% chlorhexidine mouth rinses on plaque S. mutans count.
Study Design: Forty-five study participants in the age group of 6-12 years with dmft (decay component) of three or four were selected from one government school in Bangalore city. They were divided into three groups after the restorative treatment. Group-A, Group-B, and Group-C received 1% povidone-iodine mouth rinse, 0.2% chlorhexidine mouth rinse and placebo mouth rinse, respectively, twice daily for 14 days.
The plaque sample was collected and S. mutans count was estimated at six phases:
(1) Baseline, (2) 3 weeks after restoration, (3) First day after mouth rinse therapy, (4) 15 days after mouth rinse therapy,
(5) 1 month and (6) 3 months after mouth rinse therapy
Results: After the restoration the percentage change in S. mutans count was 28.4%. Immediately after mouth rinse therapy there was significant reduction in S. mutans count in all the three groups. After which the count started to increase gradually and after 3 months the bacterial counts in the povidone-iodine group and placebo group were almost near the postrestorative count.
Conclusion: Mouth rinses can be used as adjunct to restoration for short duration as temporary measure in reduction of S. mutans count and restorations provide longer effect. In case a mouth rinse has to be used, chlorhexidine can be recommended as it has shown to have better effect than Povidone-iodine and placebo.
Keywords: Chlorhexidine, MSB agar, placebo, plaque sample, povidone-iodine, Restorations, Streptococcus mutans
|How to cite this article:|
Neeraja R, Anantharaj A, Praveen P, Karthik V, Vinitha M. The effect of povidone-iodine and chlorhexidine mouth rinses on plaque Streptococcus mutans count in 6- to 12-year-old school children: An in vivo study. J Indian Soc Pedod Prev Dent 2008;26, Suppl S1:14-8
|How to cite this URL:|
Neeraja R, Anantharaj A, Praveen P, Karthik V, Vinitha M. The effect of povidone-iodine and chlorhexidine mouth rinses on plaque Streptococcus mutans count in 6- to 12-year-old school children: An in vivo study. J Indian Soc Pedod Prev Dent [serial online] 2008 [cited 2014 Oct 23];26, Suppl S1:14-8. Available from: http://www.jisppd.com/text.asp?2008/26/5/14/41748
| Introduction|| |
Good oral health is an integral component of good general health. Many children have inadequate oral and general health because of active and uncontrolled dental caries. According to the first ever United States Surgeon General's report on oral health in America published in May 2000, dental caries is the single most common chronic childhood disease. Treating a carious tooth by providing a restoration does not cure the disease. If the unfavorable oral environment that caused the cavity persists so will the disease and more restorations will be required in time. Treating the oral infection by reducing the number of cariogenic microorganisms and establishing a favorable oral environment to promote predominantly remineralization of tooth structure over time will stop the caries process.  Streptococcus mutans has been implicated as one of the major and most virulent of the caries-producing organisms. , Children with high risk of caries have increased S. mutans count. Gaining control of S. mutans infection in these children is accomplished in two phases-caries control by restoration of cavities followed by chemotherapeutic medication.  Chlorhexidine and povidone iodine has been found to lower the mutans streptococci count in plaque and saliva. ,
Hence this study was carried was carried with the following objectives:
- To evaluate the efficacy of povidone-iodine and chlorhexidine mouth rinses on plaque S. mutans when used as an adjunct to restoration.
- To compare the anti-microbial effect of 1% povidone-iodine and 0.2% chlorhexidine mouth rinses on plaque S. mutans count.
| Materials and Methods|| |
Children in the age group of 6-12 years were examined in one government school in Bangalore city and dmft recording was done using mouth mirror and probe in natural illumination. Forty-five patients with high caries experience-dmft (decay component) of three or four were selected. 
High caries activity indicates high count of S. mutans , which means that the child belongs to high caries risk group.  Patients were included only after the parents/legal guardian signed the consent form. The design of this study and the consent forms were reviewed and approved by the ethical committee.
The Exclusion criteria were;
- Marked intra oral soft tissue pathology.
- Subjects with history of taking antibiotics 3 months prior or during the course of study.
- Medically compromised patients.
- Children with restored teeth.
- Children with decayed permanent teeth.
Baseline samples were taken and S. mutans count was estimated for all the 45 children. The sample was obtained by swabbing the buccal surfaces of all the teeth with sterile cotton swab [Figure 1]. The patient was restrained from brushing 24 hrs before the plaque sample was taken. Processing was started immediately after collection of the sample.
The swab was placed in 1 ml of 0.5 M phosphate buffer (pH 7) and was vortexed for 1 min using cyclomixer [Figure 2]. Sample dilution of 1:10 was made with the phosphate buffer solution and was then vortexed for 1 min. Using inoculating loop (4 mm diameter) the sample was streaked on mitis salivarius bacitracin agar (MSB) selective media for S. mutans [Figure 3]. The plates were incubated at 37oC for 72 hrs and the numbers of colonies were counted based on the colony morphology. The colonies have crusted glass appearance  [Figure 4]. The bacteria were confirmed by gram staining.
All the 45 children were provided restorative treatment with Fuji IX Glass-ionomer cement. After 3 weeks of restoration the plaque sample was taken and S. mutans count was estimated by the above method. A total of 45 children were then divided into three groups of 15 each.
Group A 1% povidone-iodine mouth rinse
Group B 0.2% chlorhexidine mouth rinse
Group C placebo mouth rinse
Group A subjects were instructed to rinse the mouth for 1 min with 5 ml of povidone-iodine diluted with 5 ml of water. Groups B and C subjects were instructed to rinse the mouth with 10 ml of chlorhexidine and 10 ml of placebo mouth rinse, respectively, for 1 min. The mouth rinse was given twice daily for 14 days.
Morning rinsing was under the supervision of the examiner and night rinsing was under parent's supervision. Measured amount of mouth rinse was provided in the bottle everyday after morning rinse to the children to rinse at night. Before the beginning of mouth rinse regimen the parents of all the children involved in the study were instructed and demonstrated with the mouth rinse procedure. After 14 days of mouth rinse program the plaque sample was collected and S. mutans count estimated in all the three groups. After this no mouth rinse was given.
Plaque samples were obtained from all children at six phases:
(2) 3 weeks after restorations
(3) First day after mouth rinse therapy
(4) 15 days after mouth rinse therapy
(5) 1 month and
(6) 3 months after mouth rinse therapy
| Results|| |
At baseline there was no significant difference between the groups with respect to the total number of mutans Streptococci. After restoration there was a significant decrease in the bacterial count ( P < 0.05) [Graph 1]-[Figure 5]. Students' 't'-test was carried out to compare the inhibition of S. mutans in all the three test groups at different time intervals. Inhibition of S. mutans in all the three groups was significant at first day, 15 days, and 30 days after mouth rinse therapy, but at 90 days the inhibition was significant only in chlorhexidine group [Table 1],[Table 2],[Table 3]. The counts in placebo and povidone-iodine group were almost near postrestorative count.
| Discussion|| |
Children with high DMFT have increased S. mutans count. Gaining control of S. mutans infection is accomplished in two phases-caries control by restoration of cavities followed by chemotherapeutic medication.  As a result variety of chemotherapeutic agents have been examined for their ability to control microorganisms and to affect plaque formation.
In this study, there was no significant difference between the groups with respect to the total number of plaque mutans streptococci at baseline. This can be explained by the fact that there was not much difference among the group at baseline as the dmft (decay component) was standardized. Pooled plaque samples were used to determine the levels of S. mutans. Plaque sampling was chosen because it is likely the most reliable method in children due to the higher odds ratio between caries and S. mutans in plaque samples compared to saliva. Collection of plaque also eliminated, the difficulties associated with saliva collection in children. 
The results of this study demonstrated a significant reduction in S. mutans count in all the three groups after restoration. This can be explained by the fact that once the carious lesions are eliminated most of the mutans streptococci may be eliminated as well. Various studies have been carried out to assess the S. mutans inhibitory effect of restorative materials  and it is seen that glass-ionomer cement has marked S. mutans inhibitory effect. , Some investigators suggest that successful routine restorative treatment does not alter number of S. mutans  while others have demonstrated that extensive dental treatment effectively reduces the level of caries - associated microorganisms for a period of at least 5 to 6 months. ,, Plaque samples were collected after a duration of 3 weeks following the restorative treatment using glass-ionomer cement. This can be explained by the fact that studies have shown that the release of fluorides is maximum for 24 h and reduces to become stabilized at 3 weeks. , After restoration there was significant reduction in number of plaque mutans streptococci in all the there groups but no significant difference in reduction between the groups.
In the present study, immediately after mouth rinse therapy there was significant reduction in mutans streptococci in chlorhexidine, iodine, and placebo group. Chlorhexidine was found to be more effective as compared to the other two groups. , However, subjects using iodine showed significant reduction in mutans streptococci as compared to placebo group which is similar to earlier studies. , The reduction in the count of placebo group is not because of antibacterial property it may be due to the oral hygiene practices. This can be explained by the 'hawthorne effect' or participation effect which would be an important confounding variable in clinical therapeutic trials, since the major behavioral factor that influences all outcome measures in microbial studies is the degree to which subjects improve and maintain personal oral hygiene. 
After 15 days of mouth rinse therapy there was increase in S. mutans count. But this increase is very less in chlorhexidine as compared to povidone-iodine. This is in correlation with the study according to which povidone-iodine as mouthwash exerts only an immediate antibacterial effect and unlike chlorhexidine is not retained at antibacterial level after expectoration. 
After 30 days of mouth rinse therapy, there was further increase in S. mutans counts in all the three groups. After 90 days of mouth rinse therapy, there was further increase in S. mutans counts in all the groups but the mean bacterial count in all the there groups is within the postrestorative mean bacterial count. The difference between mean postrestorative bacterial count and mean bacterial count in iodine and placebo group is not significant. This is because of loss of effect of the mouthrinse. However, the difference between postrestorative bacterial count and mean bacterial count in chlorhexidine group is significant. This can be attributed to chlorhexidine's superior antiplaque effect that can be explained in terms of its superior degree of persistence at the tooth surface or more correctly its superior persistence of antibacterial effect at the tooth surface. 
| Conclusion|| |
Mouth rinses can be used as adjunct to restoration for short duration as temporary measure in reduction of S. mutans count and restorations provide longer effect. In case a mouth rinse has to be used, chlorhexidine can be recommended as it has shown to have better effect than povidone-iodine and placebo.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3]