Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents  
Year : 2017  |  Volume : 15  |  Issue : 4  |  Page : 302-305

Comparative evaluation of mouth rinsing with plain water and an antibacterial mouth rinse on salivary pH: A randomized clinical trial

Department of Public Health Dentistry, Babu Banarasi Das College Of Dental Sciences, Lucknow, Uttar Pradesh, India

Date of Web Publication13-Dec-2017

Correspondence Address:
Dr. Shweta Singh
Paramount Apartment, New Berry Road, Lucknow, Uttar Pradesh
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jiaphd.jiaphd_54_17

Rights and Permissions

Introduction: Salivary pH plays an important role in maintaining oral health and in particular affecting dental caries. Studies have confirmed the antibacterial beneficial effects of chlorhexidine on dental health by increasing salivary pH (changing acidic pH to more neutral pH). Water, the most precious/omnipresent liquid also bears an effect on salivary pH. Materials and Methods: A double-blind concurrent parallel study design was employed on 40 individuals to evaluate changes in salivary pH before and after having meals. The study participants were divided into two groups with 20 each in Group A (those who rinsed with plain water) and Group B (those who rinsed with Chlorhexidine) who were assessed for the pH before and after meals. Results: On intragroup comparison, it was found that the mean pH of Group A was 5.56 ± 1.83 while the mean pH of Group B was 6.48 ± 1.49 after meals, which was statistically nonsignificant at P = 0.09. Conclusion: Water has a beneficial effect on salivary pH and in turn oral health, which is comparable with a standard mouth rinse.

Keywords: Antimicrobial, chlorhexidine, saliva

How to cite this article:
Singh S, Anuradha P, Sahana S, Narayan M, Agarwal S. Comparative evaluation of mouth rinsing with plain water and an antibacterial mouth rinse on salivary pH: A randomized clinical trial. J Indian Assoc Public Health Dent 2017;15:302-5

How to cite this URL:
Singh S, Anuradha P, Sahana S, Narayan M, Agarwal S. Comparative evaluation of mouth rinsing with plain water and an antibacterial mouth rinse on salivary pH: A randomized clinical trial. J Indian Assoc Public Health Dent [serial online] 2017 [cited 2023 Dec 10];15:302-5. Available from: https://journals.lww.com/aphd/pages/default.aspx/text.asp?2017/15/4/302/220715

  Introduction Top

The maintenance of oral hygiene is one of the key elements of oral health. The oral cavity harbors bacteria and is exposed to environmental stimuli such as foods, chemicals, and temperature which remain in a balanced state during healthy state of mouth. However, imbalances in equilibrium of defense mechanisms and various stimuli lead to various oral diseases such as dental caries and periodontal diseases.[1]

Salivary pH has a direct effect in maintaining oral health. Acidic pH results in demineralization and gingival inflammation.[1] Mouth rinsing results in clearance of debris and prevents accumulation of harmful bacteria, thereby promoting oral health. Saliva is a dynamic system which helps to maintain a balance of the carious process by various variables such as pH from a salivary fluid and buffer capacity.[2] Salivary pH is a good indicator of demineralization which is the first step in the carious process.[3]

Mouth rinsing can be done by plain water or commercially available rinses (mouthwashes). Mouthwashes prescribed by dentist are antiseptic solutions intended to reduce the microbial load in the oral cavity or given for other reasons such as for their analgesics, anti-inflammatory or antifungal action. In addition, some rinses act as saliva substitutes to neutralize acid and keep the mouth moist in xerostomia (dry mouth).[3],[4] Cosmetic mouth rinses are also available to temporarily mask or reduce bad breath and leave the mouth with pleasant taste.[5] However, the mouth rinses available in the market have their side effects such as taste disturbances, sensation of a dry mouth, and staining of teeth. These effects are seen in people who use mouthwash too often, especially alcohol-containing mouthwashes, which may make the mouth dry and halitosis worse since it dries the mouth.[6],[7]

One of the easiest, convenient, and cost-effective replacements of mouth rinses is plain water. The flushing action of water in oral cavity can aid in cleaning the acids present in mouth and also the fermentable carbohydrates adhering to tooth surfaces, which can further make the oral cavity acidic. The most common benefit of mouth rinsing is that it increases the salivary pH. With an increase in prevalence of dental problems, it has been well established that saliva plays a very important role in the maintenance of oral tissues. Plain mouth water rinsing as on oral care measure will require lesser cost and be easily available, which can reduce the risk of dental caries and in turn reduce the burden on health-care system. Considering this background, the present study was performed to compare the efficacy of mouth rinsing with plain water and an antibacterial available mouth rinse (chlorhexidine) on salivary pH so that the efficacy of this cost-effective oral hygiene maintenance method can be advocated for public health programs.

  Materials and Methods Top

A double-blind parallel concurrent randomized trial was employed to compare the pH readings of saliva before and after rinsing with the help of salivary pH strips. The study was cleared by Institutional Ethical Committee of Babu Banarasi Das College of Dental Sciences (BBDCODS). Informed consent of all the participants was obtained before the start of the study, after explaining the risks and benefits of the procedure.

All the recruiters fulfilled the eligibility criteria. First-year dental students (male and female) aged 18–25 years and individuals were included in this study. Individuals under any kind of medications or medical treatment for the past 3 months and day scholars as they get different meal packs were excluded. It was made sure that the dietary practices and pattern were uniform of all the students. The lunch boxes of 4 students whose salivary pH were to be monitored carefully on each day were checked to ensure they are the same.

A total of 40 volunteers including both genders of first-year dental students formed the study sample. The participants were divided into two groups with 20 individuals in each group. The two groups were marked as Group A and Group B. In Group A, two pH readings with plain water rinsing were done and in Group B, pH was recorded twice after and before rinsing with chlorhexidine mouthwash. The amount of chlorhexidine mouthwash and plain water used for the rinsing was 10–15 ml, which was measured with the measuring cup. Then salivary pH of plain water mouth rinsing and chlorhexidine rinsing was recorded.

The study was conducted by a single examiner who conducted the study by following strict infection control in 10 days. Four individuals at a time were asked to report to the Department of Public Health Dentistry during lunch time. Two individuals from both groups were examined per day. Disposable salivary strips were used as an investigation instrument to measure the salivary pH. The examiner placed the pH strips in the floor of the subject's mouth under the tongue area. It was reassured that the pH strips were uncontaminated and were kept in place for 30 s (as per manufacturer's instructions). The strips were immediately removed and color match was done against the indicator chart in the pH strips packaging. Then, the used pH strip was discarded. The pH readings in pairs were recorded in the predesigned pro forma [Chart 1].

The data collected were analyzed using SPSS 18.0 (Universal, Delhi, India) for descriptive and analytical statistics. The interpretations of the pH readings are based on the color coding chart. The pH below 6.0 shows that the body is very acidic, serious changes to the diet and lifestyle are recommended. pH between the range of 4.0–5.5 shows it to be in the acidic range which can be improved by the change in the dietary pattern to benefit the pH of one's body. The pH reading in between 6.5 and 7.5 is the optimal range to maintain the alkalizing lifestyle. Above 8 is uncommon showing salivary pH to be too alkaline which is not healthy. P < 0.05 was considered statistically significant.

  Results Top

The mean pH values in both groups before rinsing are almost similar and nonsignificant.

[Table 1] represents the pH values of both groups before rinsing. Group A rinsed with plain water whereas Group B rinsed with chlorhexidine mouthwash. The mean pH of Group A was 5.56 ± 1.83 while the mean pH of Group B was 6.48 ± 1.49, which was statistically nonsignificant at P = 0.09. Group A recorded the mean pH of 5.56 while Group B showed a mean pH of 6.48.
Table 1: Inter-group comparison

Click here to view

[Table 2] shows the mean pH of both Groups after rinsing. Group A was 5.90 ± 1.02 and that of Group B was 6.65 ± 0.58 which was significant at P = 0.007. The [Chart 2] compares the mean pH values of both groups after rinsing showing Group A at 5.9 and Group B at 6.65.
Table 2: Intra group comparison

Click here to view

[Table 3] shows the intragroup comparison of both groups with mean pH of Group A coming out to be 5.56 ± 1.83 which was based on the data collection done after having meal and before rinsing with plain water while the mean pH value after rinsing with plain water was 5.90 ± 1.02, which was statistically nonsignificant at P value to be 0.278. [Chart 3] represents the pH value of Group A before and after rinsing with plain water which is recorded to be 5.56 before rinsing and 5.9 after rinsing with plain water.
Table 3: Intra-group comparison

Click here to view

[Table 4] shows the mean pH of Group B before rinsing was 6.48 ± 1.49 while the mean pH recorded after rinsing was 6.65 ± 0.58, which was statistically nonsignificant at P value to be 0.608. [Chart 4] shows the pH value of Group B before and after rinsing with chlorhexidine mouthwash indicating mean pH to be 6.48 before rinsing and 6.65 after rinsing.
Table 4: Intra-group comparison - Group B

Click here to view

  Discussion Top

One of the most important factors in maintaining healthy dentition is the salivary pH, which is a measure of acidity or alkalinity.[8] The lower the pH, the more acidic it is, and the higher the pH, the more alkaline it is going to be. The pH scale ranges from 1 to 14 with 1 being the acidic, 14 being alkaline, and 7 being neutral (like water). A pH of 5.5 is considered critical for teeth as the teeth begin to dissolve or demineralize below 5.5. At a pH above 5.5, the teeth begin to remineralize.[8] The normal range of salivary pH is 6.2–7.6, with 6.7 being the average pH. Resting pH of mouth does not fall below 6.2 in the oral cavity. The pH is maintained near neutrality (6.7–7.3) by saliva. The saliva contributes to maintenance of the pH by two mechanisms. First, the flow of saliva eliminates carbohydrates that could be metabolized by bacteria and removes acids produced by bacteria. Second, acidity from drinks and food as well as from bacterial activity of saliva. This protective mechanism of salivary pH acts against dental caries and dental erosion.

Rinsing the mouth after meals plays a critical role in maintaining oral health. As previously described, water with pH at 7.0 proves to be cost-effective preventive measure to prevent dental caries. Saliva's main constituent is water. In addition to that, there are few enzymes and bacteria which help in normal oral health status maintenance. It is well-known fact that the low pH would result in higher incidence of caries. The higher pH will change the normal microflora, which in turn will alter the oral health affecting the periodontium adversely.[9]

The decrease in salivary pH after meals gets neutralized over a period of 15–60 min, by the oral cavity's normal mechanism. The pH can be brought down by rinsing the mouth with antibacterial rinse or plain water as its most commonly and easily available everywhere.[10]

Modern lifestyle mandates short break times and quick meals for most of those who have outdoor occupations. The oral health professional usually advise brushing teeth after eating. However, it is not feasible; some believe that rinsing mouth with tap water may also be as effective as brushing or rinsing with medicated mouth wash [10] and can be equally beneficial in reducing the chances of dental caries formation. The World Health Organization also promotes mouth rinsing through its different proposals and programs.[2]

Keeping the lifestyle and busy schedule of dental students where they have to sit for hours to attend the classes and getting short meal breaks with less or no time to look after their oral hygiene much, this present study has been performed on dental students of BBDCODS to evaluate the significant changes on salivary pH with can potentially reduce dental caries and tooth erosion from acid exposure. Several studies have already been done to prove the positive effect of mouthwash on salivary pH.[11],[12] The salivary pH is an important biomarker for dental caries and periodontal diseases. It has been already a proven fact that the mouth rinsing influence the salivary pH [11] by Chand et al. Lee and Schimtz also reported in their study that mouth rinse rises the pH of the surface of the tooth thus leading to a reduced loss of enamel and mineral structure at the tooth surface.[13],[14] Same study results were obtained by Olivia Lim where she concludes that pH of the saliva increases after mouth rinsing.[10]

In the present study, we have estimated the benefit of mouth rinsing with plain water over commercially available mouthwashes and have tried to evaluate the physiological and perceptual response of mouth rinsing with water on salivary pH.

The present study employed a pH strip (Indo Surgicals Universal) for estimating the salivary pH. A more valid method would be the biochemical assessment, which could not be followed due to practical constraints such as transportation of saliva and laboratories facilities. The confounding factors such as the use of other oral hygiene aids and variations in the oral cavity and host could not be considered in the present study. A study on a larger scale considering all the above factors is further recommended.

  Conclusion Top

This study results reinforce that simple plain water rinsing is also effective in reducing salivary pH and hence is a good preventive step to be incorporated in preventive, promotive programs aimed at reducing dental caries and gingivitis.


The authors would like to thank the volunteers for their participation in the present study.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Saliva: Of Emerging Importance in the Medical and Dental Worlds. Available from: http://www.theguardian.com'Lifestyle'Health&wellbeing. [Last accessed on 2016 Sep 20].  Back to cited text no. 1
Rosenberg M, Gelernter I, Barki M, Bar-Ness R. Day-long reduction of oral malodor by a two-phase oil: Water mouthrinse as compared to chlorhexidine and placebo rinses. J Periodontol 1992;63:39-43.  Back to cited text no. 2
Belardinelli PA, Morelatto RA, Benavidez TE, Baruzzi AM, López de Blanc SA. Effect of two mouthwashes on salivary pH. Acta Odontol Latinoam 2014;27:66-71.  Back to cited text no. 3
Matthews RW. Hot salt water mouth baths. Br Dent J 2003;195:3.  Back to cited text no. 4
Mouthwash (Mouthrinse)-American Dental Association (ADA). Available from: http://www.ada.org/en/science-research/ada-seal-of-acceptance/product/mouthrinses. [Last accessed on 2016 Sep 22].  Back to cited text no. 5
Kozlovsky A, Goldberg S, Natour I, Rogatky-Gat A, Gelernter I, Rosenberg M, et al. Efficacy of a 2-phase oil: Water mouthrinse in controlling oral malodor, gingivitis, and plaque. J Periodontol 1996;67:577-82.  Back to cited text no. 6
Cortelli JR, Thénoux RE. The effect of mouthrinses against oral microorganisms. Oral Res Braz 2007;21:23.  Back to cited text no. 7
Schuelke L. The key to cavity prevention: PH in the mouth. Northeast Wis 2015;14:12.  Back to cited text no. 8
Lim O. The Effects of mouthwash on lactoperoxidase and pH in human saliva: Helpful or harmful? Future Science Leaders: Year Two Research; 2014. p. 1-7.  Back to cited text no. 9
Osso D, Kanani N. Antiseptic mouth rinses: An update on comparative effectiveness, risks and recommendations. J Dent Hyg 2013;87:10-8.  Back to cited text no. 10
Southern EN, McCombs GB, Tolle SL, Marinak K. The comparative effects of 0.12% chlorhexidine and herbal oral rinse on dental plaque-induced gingivitis. J Dent Hyg 2006;80:1-3.  Back to cited text no. 11
Chand S, Gulati P, Dhingra S. Swatika estimating the pH of commercially available dentrifices and evaluating its effect on salivary pH after brushing. J Oral Health Comm Dent 2013;7;12-6.  Back to cited text no. 12
Lee C, Schimtz B. Determination of pH, total acid, and total ethanol in oral health products: Oxidation of ethanol and recommendations to mitigate its association with dental caries. J Dent Oral Med Dent Educ 2009;3:1-4.  Back to cited text no. 13
Marinho VC, Chong LY, Worthington HV, Walsh T. Fluoride mouthrinses for preventing dental caries in children and adolescents. Cochrane Database Syst Rev 2016;29:7. doi:10.1002/14651858.  Back to cited text no. 14


  [Table 1], [Table 2], [Table 3], [Table 4]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Materials and Me...
Article Tables

 Article Access Statistics
    PDF Downloaded741    
    Comments [Add]    

Recommend this journal