|Year : 2014 | Volume
| Issue : 3 | Page : 157-162
Efficacy of mouth rinses on dental plaque and gingivitis: A randomized, double-blind, placebo-controlled clinical trial
Arun Shyam1, Nusrath Fareed2
1 Department of Public Health Dentistry, Meghna Institute of Dental Sciences, Nizamabad, Telangana, India
2 Department of Public Health Dentistry, KVG Dental College and Hospital, Sullia, Karnataka, India
|Date of Web Publication||15-Nov-2014|
Department of Public Health Dentistry, Meghna Institute of Dental Sciences, Nizamabad 503 003, Telangana
Source of Support: None, Conflict of Interest: None
Introduction: Over the years chlorhexidine (CHX), triclosan and sodium fluoride (NaF) mouth rinses are used alone or combined in the prevention of dental diseases. However, at present little is known about the combined effects of NaF + triclosan and CHX + NaF + triclosan mouth rinses on reducing dental plaque and gingivitis. Aim: The aim was to determine the efficacy of mouth rinses used as adjuncts to regular oral hygiene measures on reducing dental plaque and gingivitis. Materials and Methods: A randomized, placebo-controlled, double-blind, parallel-group study was conducted for 6-month, among 12-15 years old school children in Nellore, India. Eligible subjects (n = 210) with consent were randomly allocated to four groups and were provided with a mouth rinse (Group A = 0.2% CHX; Group B = 0.05% sodium fluoride + 0.03% triclosan; Group C = 0.2% CHX + 0.05% sodium fluoride + 0.03% triclosan; Group D = Placebo). All subjects used 10 ml of mouth rinse, once daily for 60 s. The clinical parameters evaluated were plaque index (PlI) and gingival Index (GI). Statistical significance within and between four groups was tested using one-way analysis of variance (ANOVA), repeated measures ANOVA with post-hoc and paired t-test. Results: At the end of clinical trial, the three test groups showed statistically significant (P < 0.001) reduction in PlI and GI scores compared with placebo group. Conclusion: The active agents demonstrated highly potent antiplaque and antigingivitis properties when compared to placebo.
Keywords: Chlorhexidine, dental plaque, gingivitis, sodium fluoride, triclosan
|How to cite this article:|
Shyam A, Fareed N. Efficacy of mouth rinses on dental plaque and gingivitis: A randomized, double-blind, placebo-controlled clinical trial. J Indian Assoc Public Health Dent 2014;12:157-62
|How to cite this URL:|
Shyam A, Fareed N. Efficacy of mouth rinses on dental plaque and gingivitis: A randomized, double-blind, placebo-controlled clinical trial. J Indian Assoc Public Health Dent [serial online] 2014 [cited 2019 Nov 21];12:157-62. Available from: http://www.jiaphd.org/text.asp?2014/12/3/157/144785
| Introduction|| |
Early human dental plaque formation is initiated by the deposition of a thin biofilm mainly derived from salivary glycoproteins onto the tooth surface. When one or two layers of bacteria are present on the tooth surface in a healthy individual, the subject's immune system can cope with these microorganisms, and the subject can thus present a healthy gingiva. Therefore, disturbing plaque formation is of major importance. One approach in dental plaque control thus be to combine the use of chemical agents with the mechanical cleaning.  The rationale for the use of antiplaque agents as adjuncts to mechanical methods is based on two premises. First, plaque is the major etiological factor in gingivitis and studies of tooth cleaning suggest that mechanical cleaning methods are inadequate. 
The antiplaque agents (action through plaque effects) can be subdivided for possible modes of action against plaque: Prevent bacterial attachment (anti adhesive); inhibit bacterial division (antimicrobial agents); remove plaque ("chemical tooth brush"); and alter plaque ecology. Until date, antimicrobial agents have had the most success, with little or no achievements in the other areas. 
A number of antimicrobial agents have been studied in respect to the control of supra gingival plaque and they can be divided into bisguanide antiseptics, quaternary ammonium antiseptics, phenolic antiseptics, other antiseptics, oxygenating agents, metal ions and natural products.  The cationic bis-biguanide chlorhexidine (CHX) is the gold standard antimicrobial agent.  Several studies have proved the efficacy of CHX digluconate mouth rinse in reducing gingivitis and dental plaque accumulation. , Triclosan, a broad-spectrum, lipid-soluble agent, is widely used in toothpastes and mouth rinses to reduce plaque formation and to improve gingival health. ,, It, has a double barrel effect both antibacterial and antiinflammatory. 
The efficacy of 0.05% sodium fluoride mouth rinse in caries control is well-established.  However, there is little evidence to suggest its effectiveness on dental plaque and gingivitis. One potentially useful combination of CHX in any oral hygiene product would be fluoride.  The results of a 2-year clinical trial involving the use of combined CHX (0.05%) and sodium fluoride (0.044%) mouth rinse showed a significant reduction in gingival bleeding as well as the least DMFS increment.  In studies conducted for 8 weeks and 6 weeks, combined CHX and sodium fluoride mouth rinse demonstrated a significant inhibitory effect on plaque and gingival bleeding. , In a cross-over study, fluoride/triclosan/oil rinse failed to demonstrate any clinically significant advantage over the control rinse at 24 or 96 h in inhibiting dental plaque. 
Over the years CHX, triclosan and sodium fluoride (NaF) mouth rinses are used alone or combined in the prevention of dental diseases. However, at present, little is known about the combined effects of NaF + triclosan formulation and addition of CHX to NaF + triclosan mouth rinse on dental plaque and gingivitis. Therefore, this study was designed and carried out to assess the efficacy of CHX, sodium fluoride plus triclosan or CHX in combination with sodium fluoride and triclosan as mouth rinses for dental plaque accumulation and gingivitis using a protocol that satisfied the American dental association council on dental therapeutics (CDT-1986) guidelines for clinical trials.
| Materials and Methods|| |
An institutional review board and Ethical Committee gave approval for the study (IEC/1091/04.01.2010). This study was performed in accordance with the guidelines of Good Clinical Practice and Declaration of Helsinki as revised in 2000. The investigator provided detailed information about the study procedure, the benefits and the possible side-effects associated with the trial to the parents, and written consent was obtained.
A randomized, placebo-controlled, double-blinded, parallel-group study was conducted for 6-month among 12-15 years old school children in Nellore, India. The inclusion criteria were: (1) Children with fully erupted permanent dentition; (2) baseline plaque index (PlI) and gingival index (GI) scores of 2-3 (3) apparently healthy and (4) an ability to use a mouth rinse. The exclusion criteria were: (1) Subjects undergoing orthodontic treatment (2) subjects with an intraoral prosthesis (3) medically compromised subjects.
A pilot study was conducted on 50 subjects before the main study to standardize the methods. The sample size with the power of 80% and α error of 0.05% was estimated based on the pilot study data. Additional 5% of the subjects were added to the estimated sample of 200 to compensate for sampling loss, if any. Thus, the final sample accounted for 210 and the study subjects were selected from among 450 school children upon satisfying the inclusion and exclusion criteria.
Randomization and blinding
Manufacturing company M/S Group Pharmaceuticals was requested to provide the required quantity of mouth rinses in a precoded consignment of identical bottles that are color coded. Pharmaceutical company considered the request and provided samples free of cost. The children were drawn from three randomly selected schools of Nellore city. The eligible children from each school were randomly allocated into four groups (A, B, C and D) using computer-generated random numbers. The investigator and the participants were unaware of the group allocation and the composition of the mouth rinse received by the respective groups. Decoding was done by the manufacturing company after the analysis of results.
Data recording was done by a recorder who had been trained and calibrated prior to the main study. To evaluate the intra-examiner reliability, duplicate examinations were conducted. The related kappa values were 0.84, 0.92 and 0.94 for clinical examinations at various phases of the study.
Clinical examinations were performed over a period of 5 days each at baseline, 3-month and 6-month. At the baseline examination, personal information of the subjects was recorded in a specially prepared pro-forma. The children were examined on a chair by the investigator under good illumination using a mouth mirror and an explorer. At each intraoral examination, presence of plaque and gingivitis was determined using the criteria suggested by Loe.  PlI and GI scores were recorded on all surfaces (mesial, distal, buccal, palatal/lingual) of all the teeth. The scores from the four areas of the tooth were added and divided by four to give the PlI/GI for the tooth. PlI and GI for the individual is obtained by adding the indices for the teeth and dividing by the number of teeth examined. Reduction in PlI score was considered as the primary outcome and difference in GI scores between four groups was the secondary outcome.
The investigator demonstrated and trained the subjects regarding a proper method of mouth rinsing. Ten milliliters of mouth rinse from the respective bottles was measured using a graduated plastic jar and dispensed to the subjects. They were made to rinse thoroughly once daily for 60 s and spit out the solution. After this procedure, the children were instructed not to eat or drink anything for about 30 min. The above procedure was repeated on each school day during morning hours for a period of 6-month, starting October 2010. The subjects were instructed to report any adverse events such as sickness, change in taste perception, soreness of the tongue, edema, redness, sensitivity, burning sensation of the oral mucosa and visible staining during the course of the study, to the class teacher or investigator. Such a finding was duly recorded in the pro-forma.
Statistical analysis was performed on an intention-to-treat basis, with missing data being imputed as the same as data from the inclusion period. The alpha (α) level of significance was taken as 0.05, and the confidence intervals were set at 95%. Statistical significance within and between four groups was tested using one-way analysis of variance (ANOVA), repeated measures ANOVA with post-hoc and paired t-test, using the program SPSS for Windows (version 17.0; SPSS Inc., Chicago, IL, USA).
| Results|| |
A consort flow chart of study design and number of subjects at each phase of the study has been described [Figure 1]. [Table 1] shows basic demographic characteristics of the study subjects. The overall dropout rate was remarkably small (2.85%) and it has had negligible influence on the results. During the entire study period, differences in dietary habits or oral hygiene practices were slight and not significant among the four groups.
[Table 2] and [Table 3] shows the mean PlI and GI scores of each group at 3 times points. It indicates that within and between group difference at baseline is not significant for PlI and GI, thus at baseline all four groups are similar. At 3-month and 6-month time interval, PlI and GI scores were highly significant in all the groups, revealing existing difference between the groups. Mean PlI scores from baseline to 6-month was calculated among four groups. It was found that 67% of C group subjects had a significant reduction in mean PlI, followed by A (56%) and B groups (45%). However, D group subjects showed a slight increase in mean PlI score from baseline (2.51 ± 0.32) to 6-month (2.68 ± 0.34).
Repeated measures ANOVA was carried out for both PlI and GI scores. The Greenhouse geisser was highly significant for both PlI and GI scores and thereby showed the difference in scores over a period of time. A multiple comparisons was done using the bonferroni post-hoc test to compare PlI and GI scores between the groups and the results demonstrate that the difference in mean scores is significant between the groups. Group C has highly significant difference in mean scores as compared to other groups with the P < 0.001 [Table 4] and [Table 5].
Comparison of baseline to 6-month mean GI scores revealed that 64% of C group subjects had a significant reduction in mean GI, followed by A (53%) and B groups (45%). A slight increase in mean GI score was observed among D group subjects from baseline (2.49 ± 0.31) to 6-month (2.65 ± 0.35).
| Discussion|| |
The present trial determines the efficacy of three mouth rinses on reducing dental plaque and gingivitis. In this study, school children aged 12-15 years were included since 12-year is the global monitoring age for dental caries and 15-year age for the assessment of periodontal disease indicators in adolescents.  Mouth rinses with active agents, alone or combined, in the treatment of dental plaque and gingivitis, were tested among school children in previous studies. ,, This study was intended to find the cumulative effect of mouth rinsing and hence a standard protocol of clinical examination was done within 30 min after rinsing. Further, no precautions were taken to change subjects normal oral hygiene methods.
After completion of statistical analysis, the pharmaceutical company revealed the content of the mouth rinses to be as follows: Group A = 0.2% CHX; Group B = 0.05% sodium fluoride + 0.03% triclosan; Group C = 0.2% CHX + 0.05% sodium fluoride + 0.03% triclosan; Group D = Placebo.
This study was conducted in accordance with the American dental association CDT-1986 guidelines for clinical trials. These guidelines require that clinical trials: Be cross-over or parallel-designed, study subjects should represent typical product users, active agent should be compared with a placebo or active control, dental plaque and gingivitis scoring be conducted at baseline, 6-month and an intermediate interval. 
The results of this study conducted over a period of 3-month demonstrated a significant reduction in the mean PlI and GI scores compared with baseline in A, B and C groups (P < 0.001). It was found that there was a slight reduction in mean PlI and GI among D group subjects who used a placebo rinse. This can be explained on the basis of the Hawthorne effect or Participation effect, which can be an important confounding variable in clinical therapeutic trials.  At 6-month again there were statistically significant differences in mean PlI and GI scores between the A, B and C groups compared with baseline. However, a slight increase in mean PlI and GI scores were observed among the D group, indicating that the Hawthorne effect was possibly nullified. The other potential bias if any was eliminated through randomization and blinding.
Use of 0.05% NaF + 0.03% triclosan mouth rinse produced a significant reduction in mean PlI and GI scores (P < 0.001). In fact, 0.05% NaF + 0.03% Triclosan mouth rinse provided better mean reduction compared with placebo. However, the reduction achieved was less than that of using plain 0.2% CHX and 0.2% CHX + 0.05% NaF + 0.03% Triclosan mouth rinse. This lesser reduction in PlI and GI scores when compared to the other two active agents could be attributed to the facts that NaF does not exhibit any significant substantivity, so categorized as first-generation antimicrobial agent  and effectiveness of triclosan is dose dependent. 
Significant reduction in mean PlI and GI scores on use of 0.05% NaF + 0.03% Triclosan mouth rinse could be due to the use of a solution which possesses antibacterial, antiplaque and antiinflammatory effects. Triclosan has both antibacterial and antiinflammatory effects. This unique feature is not provided so far by any other antibacterial and antiplaque agents.  The safety, antiplaque and antigingivitis properties of triclosan have been reported in the literature. ,,, The results obtained in this study on use of fluoride/triclosan mouth rinse are in contrary to the findings of a cross-over study in which fluoride/triclosan/oil rinse failed to demonstrate any clinically significant advantage over the control rinse at 24 or 96 h in inhibiting dental plaque. 
Over the decades, a number of clinical trials have clearly documented the beneficial effects of CHX in the control of plaque and gingivitis. , Lang et al.  tested the effects of supervised rinsing with CHX in 158 school children, aged 10-12 years. After 6-month, it was concluded that gingivitis can be controlled successfully by regularly using 0.1% or 0.2% CHX mouth rinses. The results of this study on the use of 0.2% CHX are in agreement with the study of Lang et al.  In this study, 0.2% CHX was chosen as one of the active agent as it is considered the gold standard against which other antiplaque agents are measured.  The reduction in PlI and GI scores on using CHX could be attributed to the prolonged antibacterial activity and dual antibacterial effect of CHX at the tooth surface, as a result of its di-cationic nature as described by Jones. 
Results of this study showed that mouth rinse with combined agents of 0.2% CHX + 0.05% NaF + 0.03% Triclosan is superior in reducing mean PlI and GI scores. This finding was in agreement with those of other studies, which tested combined active agents of CHX and NaF on caries/dental plaque/gingivitis. ,,, In this study, one possible reason for the superior effect of CHX + NaF + Triclosan in reducing plaque and gingivitis, when compared to other two mouth rinses could be attributed to the synergetic effect when the three agents are used together. In a clinical trial Luoma et al.  suggested that there would be a possible synergistic effect when the two agents (CHX, NaF) are used together.
Local side-effects such as staining of teeth and disturbance in taste were reported between 60% of subjects who rinsed with 0.2% CHX + 0.05% NaF + 0.03% Triclosan solution and plain 0.2% CHX. The role of CHX in causing these side-effects are reported in the literature. , However, the role of triclosan and sodium fluoride in causing these effects needs to be studied further. The external validity of this study can be considered to be good may be because the study design is randomized controlled trial, and it is done under natural conditions. This study has not taken into consideration the financial implications upon the subjects in case the procedure has to be implemented at the community level daily. We do not have any conflict of interest.
| Conclusion|| |
Within the limitations of the present trial, it can be concluded that the active agents used in this study demonstrated highly potent antiplaque and antigingivitis properties when compared to placebo. The adjunctive use of these active agents in daily oral hygiene practices is warranted.
| Acknowledgments|| |
We gratefully acknowledge the support and assistance of the Group Pharmaceuticals, Bangalore, India. We thank Mr. John Michael (Bio-statistician) for his help in statistical analysis.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]