Bhat2014
Bhat2014
Nagesh Bhat, Ruchi Mitra*, Swapnil Oza, Vinayak Kumar Mantu, Sharda Bishnoi,
Mandeepsinh Gohil and Rupam Gupta
which have antiseptic or antimicrobial action have been             and antigingivitis properties of a herbal mouthwash with
used, with variable success, to inhibit supragingival plaque        chlorhexidine mouthwash among the study participants.
formation and the development of gingivitis. Several chemi-
cal antiplaque agents have been tested but none has shown
equal or better results than chlorhexidine without eliciting
unfavourable side effects [5, 6].
                                                                    Materials and methods
     In order to overcome such side effects, the World
Health Organization (WHO) advice researchers to investi-            Study population
gate the possible use of natural products such as herb
and plant extracts. Plants and naturally derived products           The present study was a double-blinded, parallel
from plants have been used to enhance health and have               designed randomized clinical trial carried out in the
been used for medicinal purposes for thousands of year.             Department of Public Health Dentistry, Darshan Dental
Most herbal supplements have been utilized for centuries            College and Hospital, Udaipur, Rajasthan, India. It
based on empirical and testimonial support for their                included a total of 72 undergraduate students (37 males
efficacy. Development in alternative medicine research              and 35 females in the age group of 18–24 years). The
has led to many mouthrinses and toothpastes based on                ethical clearance was obtained from the Ethical Review
plant extracts [4].                                                 Committee of the institution and a written informed con-
     A number of clinical studies have shown the effects            sent was obtained from the study participants after
of using mouth washes extracted from herbs such as                  explaining in detail about the study.
Sanguinarina, Myrtus communis, Quercus infectoria,
Capparis spinosa and Cinnamon in the prevention of den-
tal plaque accumulation [7, 8]. Recently, a herbal                  Inclusion criteria
mouthwash has been introduced in clinical practice,
which consists of the extracts of Salvadora persica,                The dental students with age group of 18–24 years, stu-
Terminalia bellerica, Piper betle, essential oils namely            dents willing to participate and with dentition of ≥20
Gaultheria fragrantissima, Elettaria cardamomum, fla-               teeth and a minimum of 5 teeth per quadrant, no relevant
vouring agents Mentha and Trachyspermum ammi. The                   medical history and no periodontal treatment during past
natural herb S. persica is a medicinal plant whose roots            3 months were included.
have been used by many people in Africa, South
America, Middle East and Asia. The precise method for
use of Miswak was recorded by Babylonian 5000 B.C. and              Exclusion criteria
the fashion ultimately spread throughout the Greek and
Romanian empire. S. persica has anticariogenic and anti-            Students with orthodontic appliances or severe misa-
plaque effects [9]. P. betle and E. cardamomum have                 ligned teeth, receiving antibiotic therapy or medication
antibiotic action. T. bellerica is an anti-inflammatory             within past 6 months, presence of any systemic illness,
and immunity booster. Also, Mentha and T. ammi which                subjects availing oral prophylaxis since past 6 months
are naturally flavouring agents prevent halitosis.                  and students unable to comply with study appointment
     The widespread use of mouthwashes as an aid to oral            schedule were excluded.
hygiene is a relatively recent phenomenon in the devel-
oping countries of the world. Also, the cost-effectiveness
of the herbal mouthwash is less as compared to other                Test solutions
commercially available chemical-based mouthwashes.
Hence, herbal dental products are becoming popular                  Group A (Herbal Mouthwash) Hiora® mouthwash
among general public.                                               (Himalaya Drug Company, Bangalore, India). Each gram
     The in vitro studies conducted on the efficacy of the          of herbal mouthwash contains extracts of Pilu (S. persica)
herbal mouthwash suggest that the herbal mouthwash                  5.0 mg, Bibhitaka (T. bellerica) 10.0 mg, Nagavalli (P.
may be used as compared to chlorhexidine mouthwash.                 betle) 10.0 mg, oils Gandhapura taila (G. fragrantissima)
Hence clinical trials are being conducted to see the efficacy       1.2 mg, Ela (E. cardamomum) 0.2 mg, flavouring agents
of herbal mouthwash in the oral cavity. In this study, an           Peppermint satva (Mentha spp.) 1.6 mg and Yavani satva
attempt was made to compare the efficacy on plaque, safety          (Trachyspermum ammi) 0.4 mg.
    Group B (Chlorhexidine Mouthwash) ClohexPlus®                 intraexaminer was 0.90 and 0.94 respectively showing
mouthwash (Dr Reddy’s Lab Ltd. Hyderabad, India) contain-         high degree of conformity in observational judgment.
ing 0.20% w/v chlorhexidine was used in the present study.        All recordings were made by a single examiner. Plaque
    Group C (Normal Saline) Nirlife® mouthwash (Inven             was assessed on the labial, buccal and lingual surfaces of
Pharmaceuticals Pvt. Ltd.; Dhar, Madhya Pradesh, India)           all teeth after using disclosing agent (Two-tone dye). The
containing 0.05% saline was used in the present study.            severity of gingivitis was scored by examining the tissues
Normal saline was coloured to resemble the                        surrounding each tooth that were divided into four gingi-
mouthwashes.                                                      val scoring units: distal-facial papilla, facial margin,
                                                                  mesial-facial papilla and the entire lingual gingival
                                                                  margin.
Study design                                                           All the participants were instructed to follow their
                                                                  routine oral hygiene practices along with the assigned
In order to check the feasibility and validity of the study,      regimen and to maintain a reminder sheet on daily pro-
a pilot study was carried out. It also meant to assess the        duct use. Each one of the daily rinses was supervised on
acceptability and regularity of using these mouthwashes.          each weekday and also supervised by a daily recall mes-
From the pilot study, it was found that the overall pre-          sage for reminding them to use the assigned mouthwash.
valence of plaque and gingivitis was 80%. Considering             The compliance was checked with the help of a reminder
for the dropouts logistic and technical problems the sam-         sheet by the examiner during surprise recall of the parti-
ple size was inflated by 20%, hence the sample size was           cipants. Also, the participants were recalled along with
72 with 24 participants in each group. A self-designed            the mouthwash bottles assigned to check for the
pretested proforma which consisted of three parts: First          mouthwash volume used by the participants.
demographic information like name, age, sex and
informed written consent. Second part gingival index
and plaque index recorded at baseline and after 1-                Statistical analysis
month trial. The third part a questionnaire related to the
complaints or discomfort like pain, burning sensation/            The obtained data were compiled systematically. Data
itching, dryness of mouth, taste disturbance and disco-           collected were coded, computerized and analyzed using
loration of teeth if any.                                         Statistical package for Social Sciences (SPSS version
     The assignment of the participants to the groups and         17.0). One-way ANOVA and Student’s t-test were used to
the codes to the product was done by a person not                 compare the means of plaque and gingival index values
involved in the examination. All the subjects were pro-           between the three mouthwashes.
vided with their assigned mouthrinses and were divided
into Group A, Group B and Group C randomly using
simple lottery method with 24 participants in each                Results
group. All the mouthrinses were dispensed in the identi-
cal bottles and thereby ensuring a total subject masking.         The study participants were selected according to the
The examiner and the participants were also blinded with          inclusion and exclusion criteria. A total of 72 students
regard to the mouthrinse allocated to them thereby ensur-         participated in the study out of which 37 were males and
ing a double-blinded study. Subjects were provided with           35 were females with 24 students in each group in the
measuring cups of 10 mL and were instructed to use                beginning of the study. However, two students did not
10 mL of mouthwash for 1 min carried out twice a day              report after 1 month in spite of several recalls, three
after tooth brushing for a period of 4 weeks (1 month).           students were irregular in using mouthwash found dur-
     The gingival index Loe and Silness 1963 and                  ing surprise visit and one of the students became ill and
Turesky–Gilmore–Glickman          1970    modification    of      had to quit the study due to antibiotic coverage. Hence, a
Quigley–Hein plaque index were used to record the effi-           total of 66 students participated of which 32 were females
cacy before rinsing (at baseline) and after 1 month. Prior        and 34 were males with 22 students in each group. The
to the start of the study training and calibration was done       mean age for herbal group, chlorhexidine group and
in order to check the feasibility and reliability of the          saline group was 20.2  0.7, 20.95  .1 and 20.79±1.2
study. The Kappa statistical analysis for interexaminer           respectively. There was statistically no significant differ-
variability for Turesky et al. plaque index and Loe and           ence (p ¼ 0.356) in the mean age of herbal (Group A),
Silness gingival index was 0.89 and 0.97, whereas the             chlorhexidine (Group B) and saline groups (Group C).
Table 1 Comparison among the three mouthwashes on plaque index using one-way ANOVA.
Prerinsing PI (Baseline)
Postrinsing PI
Table 2 Comparison among the three mouthwashes on gingival index using one-way ANOVA.
Prerinsing (Baseline)
Postrinsing
There was no statistically significant difference between the                     Group A mouthwash showed the highest mean dif-
baseline plaque scores as compared to the three mouthwash                    ference of gingival scores between baseline and after 1
groups (p=0.87), but there was statistically highly significant              month (0.34) while the least was 0.12 observed in saline
difference (p=0.00) observed between the three mouthwash                     group. Group A and Group C showed a statistically sig-
when compared after 1 month.                                                 nificant difference (p ¼ 0.003), statistically highly signifi-
     The baseline gingival index scores between the three                    cant difference between Group B and Group C (p ¼ 0.001)
mouthwashes were statistically nonsignificant (p ¼ 0.92),                    but statistically no significant difference between Group
whereas after 1 month, there was statistically highly sig-                   A and Group B (p ¼ 0.229) (Table 4).
nificant (p ¼ 0.001) difference (Table 1 and 2).
     The mean difference between the baseline plaque
index and postrinsing plaque index after 1 month was                         Mean values of plaque index
highest in Group A (0.74) and least in Group C (–0.09). A
statistically significant difference (p ¼ 0.004) between                     The mean plaque index scores of the mouthwashes at
Group A and Group C and a statistically highly significant                   baseline were 1.5±0.32, 1.22±0.25 and 1.34±0.48 respec-
difference (p ¼ 0.00) was observed between Group B and                       tively. The highest mean plaque index after 1 month
Group C but statistically no significant difference between                  was in Group C (1.46±0.19), the least mean plaque scores
Group A and Group B (p ¼ 0.435) (Table 3).                                   after 1 month was 0.68±0.14 in Group B. The range for
Table 3 Comparison of the plaque index between mouthwashes by          1 respectively, whereas after 1 month the range observed
unpaired Student’s t-test.                                             for postrinsing gingival index was 0.68, 0.42 and 2.4
                                                                       respectively (Figure 2).
Groups       Mean       Mean        df      t-Value         p-Value
Figure 1 The distribution of the postrinsing plaque index scores of different groups after 1 month.
Figure 2 The distribution of the postrinsing gingival index scores after 1 month.
group was 20.2±0.7, 20.95±1.1 and 20.79±1.2 respectively.             Persica mouthwash with that of a placebo using Silness
There was no significant difference (p ¼ 0.356) between               and Loe plaque index.
the mean age of the three groups. The study shows                         As evident from the result of the present study, there
population selected was homogeneous which was similar                 was no significant difference in baseline plaque index
to other studies [10, 11].                                            (p ¼ 0.87) between the three mouthwashes. In the present
    As compared to the present study, few studies have                study, the herbal mouthwash showed plaque inhibition
been done with relatively favourable results as exhibited             which lay between the negative and positive control
by herbal mouthrinses. Similar to our study, studies con-             (Table 2). A statistically significant suppression of plaque
ducted by Parwani et al. [12] and Sikka et al. [13] com-              formation was seen with herbal formulation as compared
pared chlorhexidine and herbal mouthwash using Loe                    to placebo solution (p ¼ 0.004) and statistically nonsigni-
and Silness gingival index and Turesky et al. plaque                  ficant result with chlorhexidine mouthwash (p ¼ 0.435)
index. Whereas study done by Scherer et al. [14] com-                 showing that chlorhexidine and herbal mouthwash had
pared herbal mouthwash and distilled water using Loe                  a comparable effect on plaque formation. The plaque
and Silness gingival index. Another study conducted by                preventing potential of herbal mouthwash, demonstrated
Khalessi et al. [15] compared the oral health efficacy of             in the present investigation, can be attributed to its
constituents like S. persica, P. betle, T. bellerica, E. carda-     with a substantivity of 8–12 h is considered highly effec-
momum and others. S. persica, toothbrush tree, locally              tive [28], whereas Hiora herbal mouthwash substantivity
called “Miswak” has been proven as an antiplaque agent              is not yet known. On other hand, Jenkin et al. stated that
by numerous studies [12, 16]. Its antiplaque activity might         chlorhexidine had immediate bactericidal action on pla-
be due to its antimicrobial activity against early and late         que bacteria and plaque fungi and was among the most
plaque formers. Sofrata et al. [17] reported antibacterial          effective active agents to reduce and inhibit plaque accu-
effect of S. persica against oral pathogens such as                 mulation. It was able to kill both gram-positive and gram-
Streptococcus      mutans,     Lactobacillus       acidophilus,     negative microbes. This could be due to the mechanism
Actinobacillus actinomycetemcomitans, Porphyromonas                 of action of chlorhexidine on bacteria, which involves the
gingivalis and Haemophilus influenza. These findings are            disruption of bacterial cell membrane [31]
also supported by the studies of Darout et al. [18] and                  In the past, many studies suggested that chlorhexi-
Almas et al. [19]. However, when antimicrobial effect of S.         dine had the ability to reduce plaque formation and also
persica and CHX against S. mutans was compared, chlor-              improved the gingival status. The Hiora mouthwash used
hexidine was found to be more potent in reducing the                in this study is a new commercially available mouthwash
number of S. mutans colonies [20]. Another constituent of           with many components having antimicrobial, antifungal,
the herbal mouthwash, P. betle, has been documented to              antiseptic properties which have been considered in
reduce significantly the cell-surface hydrophobicity of             reducing plaque and gingival scores over a period of
three early plaque settlers such as Streptococcus mitis,            time. Khalessi et al. [19] in their study compared the
Streptococcus sanguis and Actinomyces species [21, 22].             oral health efficacy of persica mouthwash (herbal
This cell-surface hydrophobicity was well established as            mouthwash) containing an extract of S. persica with
a factor involved in the adherence of bacteria to the host          that of a placebo. Plaque accumulation and gingival
tissues [23]. Furthermore, E. cardamomum has been                   bleeding were measured before and immediately follow-
reported to significantly inhibit the growth of oral micro-         ing the examination period. They concluded that herbal
flora in in vitro studies [24, 25]. Besides the above-men-          mouthwash resulted in improved gingival health when
tioned ingredients, T. bellerica, Mentha Spp. and                   compared with prerinsing values. Moran et al. [32] con-
G. fragrantissima has also proven to possess antimicro-             ducted a study on comparison of a natural product,
bial activity that might contribute to the antiplaque               triclosan and chlorhexidine mouthwashes in a 4 day
activity exhibited by the herbal mouthwash [26–28].                 plaque regrowth model. They concluded that the natural
Our study was consistent with a study done by Rahmani               product was second to chlorhexidine in plaque inhibi-
et al. [29] which assessed the effects of S. persica and            tion. Studies on the plant extract sanguinarine chloride
CHX on plaque formation and noted a comparable                      mouthwash and toothpaste have shown that it produces
plaque inhibition by both the solutions. In our study,              moderate reduction in plaque and gingivitis.
there was a statistically highly significant suppression                 Although the plaque regrowth and antigingivitis
of plaque by chlorhexidine as compared to placebo                   effect of the chlorhexidine mouthwash was superior to
which was similar to other studies conducted by Gazi                that of herbal mouthwash over placebo, the response of
et al. [30].                                                        participants to the herbal product, as evaluated by ques-
     The mean gingival index at baseline was statistically          tionnaire, was good. There was mild transient burning
nonsignificant between the three mouthwashes (p ¼ 0.92)             sensation with intake of herbal mouthrinse which could
which was consistent with other studies [10, 11].                   be explained due to its concentrated nature. No other
However, the mean gingival index after 1 month was                  side effects had been noticed at the end of the study,
highly significant between chlorhexidine group and sal-             which might add to its clinical usage as an adjunct to
ine group (p ¼ 0.001), statistically significant between            mechanical oral hygiene measures, whereas chlorhexi-
herbal group and saline group (p ¼ 0.003), whereas the              dine mouthwash showed many adverse effects. A major-
herbal and chlorhexidine group were potentially equiva-             ity of participants in chlorhexidine group (81.8%)
lent in reducing gingivitis (p ¼ 0.229). Our results were           complained of mild discoloration, moderate discoloration
similar to the results of other studies conducted by                (9.1%), dry mouth (81.8%), transient taste disturbance
Parwani et al. [12] where herbal and chlorhexidine                  (45.4%) and burning sensation (50%). These results
mouthwashes showed a comparable antigingivitis effect               were similar to other studies [10, 22].
(p ¼ 0.244). Lang LP stated that the substantivity of an                 On the basis of the results obtained, it can be stated
antimicrobial agent needs sufficient contact time with a            that the herbal mouthwash had a promising plaque inhi-
microorganism in order to inhibit or kill it. Chlorhexidine         bitory potential. However, studies of longer duration with
cross-over study design and wash out period would have                 in Xerostomics, sugar as in patients suffering from
been more authenticating as it eliminates the bias of                  Diabetes and people who wish to avoid any artificial pre-
viable host. Further studies where safety and microbiolo-              servatives and artificial colours. Also when socioeconomic
gical parameters would be evaluated are essential to                   factor, side effects of chlorhexidine and liking of the peo-
establish the true effectiveness of the mouthrinse and                 ple for natural product need consideration, the herbal
its position among the other rinses that are used adjunc-              mouthwash can serve as a good alternative.
tively to mechanical oral hygiene procedure.                                However, safety and microbiological parameters
     Hence, the discovery of bioactive natural products                need be evaluated that are essential to establish the
which can reduce the oral diseases may serve as leads                  true effectiveness of this mouthrinse and its position
in the development of new pharmaceuticals that will be                 among other rinses that are used adjunctively to mechan-
able to address the unmet therapeutic needs in the treat-              ical oral hygiene procedures. There is need for hour to
ment of various oral diseases at low costs and can be                  investigate other upcoming mouthwashes so as to prove
used as alternatives to chemical mouthwashes.                          their efficacy as equivalent in reducing the plaque scores
                                                                       and gingival inflammation. Hence from public health
                                                                       point, the findings of the present study suggest that the
Conclusions                                                            herbal mouthwash can serve as a better alternative and
                                                                       can be prescribed in clinical practice.
The efficacy of herbal mouthwash was equally effective in
reducing plaque and gingivitis as compared to chlorhex-                Conflict of interest statement
idine mouthwash. Though chlorhexidine mouthwash con-
sidered as a gold standard, it was reported with a number              Authors’ conflict of interest disclosure: The authors sta-
of local side effects including extrinsic tooth and tongue             ted that there are no conflicts of interest regarding the
brown staining, taste disturbance, dryness of mouth, burn-             publication of this article.
ing sensation. These side effects limit its acceptability to           Research funding: None declared.
users and its long-term use. Whereas Hiora Herbal                      Employment or leadership: None declared.
mouthwash due to its natural ingredients had no reported               Honorarium: None declared.
side effects apart from mild burning sensation. In public
health point of view, the herbal mouthwash can serve as a              Received January 11, 2014; accepted March 8, 2014; previously
good alternative to patients who wish to avoid alcohol as              published online April 3, 2014
References
 1. Petersen PE, Yamamoto T. Improving the oral health of older          7. Al-Bayaty FH, Al-Koubaisi AH, Ali NW, Abdulla MA. Effect of
    people: the approach of the WHO global oral health pro-                 mouthwash extracted from salvadora persica on dental
    gramme. Community Dent Oral Epidemiol 2005;33:81–92.                    plaque formation, a clinical trial. J Med Plant Res
 2. Madianos PN, Bobetsis YA, Kinane DF. Generation of inflam-              2010;4:1446–9.
    matory stimuli, how bacteria set up inflammatory responses in        8. Fouad H, Mahmouad WH. The efficacy of Capparis spinosa
    the gingiva. J Clin Periodontol 2005;32:57–71.                          herbal extract as an antiplaque agent. J Coll Dent
 3. Loe H, Theilade E, Jensen SB. Experimental gingivitis in man. J         2001;10:85–95.
    Periodontol 1965;36:177–87.                                          9. Alali F, Lafi T. GC-MS analysis and bioactivity testing of volatile
 4. Barnett ML. The role of therapeutic antimicrobial mouthrinses           oil from the leaves of the toothbrush tree Salvodora persica.
    in clinical practice, control of supragingival plaque and gingi-        Nat Prod Res 2003;17:189–94.
    vitis. J Am Dent Assoc 2003;134:699–704.                            10. Christof D, Lang NP, Cosyn J, Persson G. A randomized, con-
 5. Hellden L, Comosci D, Hoch J, Tinanoff N. Clinical study to             trolled clinical trial on the clinical, microbiological and stain-
    compare the effect of stannous fluoride and chlorhexidine               ing effects of a novel 0.05% chlorhexidine, herbal extract and
    mouth rinses on plaque formation. J Clin Periodontol                    a 0.1% chlorhexidine mouthrinse adjunct to periodontal sur-
    1981;8:12–16.                                                           gery. J Clin Periodontol 2010;37:988–97.
 6. Addy M, Moran M, Newcomb R, Warren P. The comparative tea           11. Pai MR, Acharya LD, Udupa N. Evaluation of antiplaque activity
    staining potential of phenolic, chlorhexidine and antiadhesive          of Azadirachta indica leaf extract gel-a 6-week clinical study. J
    mouth-rinses. J Clin Periodontol 1995;22:929–34.                        Ethnopharmacol 2004;90:99–103.
12. Parwani SR, Parwani RN, Chitnis PJ, Dadlani HP. Comparative          22. Fatilah AR, Rahim ZH. The anti-adherence effect of Piper betle
    evaluation of antiplaque efficacy of herbal and 0.2%                     and Pisidium guajava extracts in oral health maintenance. J
    Chlorhexidine gluconate mouthwash in a 4 day plaque                      Oral Sci 2003;45:201–6.
    regrowth study. J Indian Soc Periodontol 2013;17:72–7.               23. Gibbons RJ, Etherden I. Comparative hydrophobicities of oral
13. Sikka G, Dodwad V, Chandrashekar KT. Comparative anti-pla-               bacteria and their adherence to salivary pellicles. Infect Immun
    que and anti-gingivitis efficacy of two commercially available           1983;41:1190–6.
    mouthwashes – 4 weeks clinical study. J Oral Health                  24. Bissa S, Songara D, Bohra A. Traditions of oral hygiene:
    Community Dent 2011;5:110–12.                                            chewing of betel (Piper betle L.) leaves. Curr Sci
14. Scherer W, Gultz J, Lee SS, Kaim J. The ability of an herbal mou-        2007;92:26–8.
    thrinse to reduce gingival bleeding. J Clin Dent 1998;9:97–100.      25. Bissa S, Songara D, Bohna A. Traditions in oral hygiene: chewing
15. Kalessi AM, Pack AR, Thomson WM, Tomkins GR. An in vitro                 of betel (Piper betle L.) leaves. Curr Sci 2008;92:26–8.
    study of the plaque control efficacy of persica, a commercially      26. Elizabeth KM. Antimicrobial activity of Terminalia bellerica.
    available herbal mouthwash containing extracts of salvadora              Indian J Clin Biochem 2005;20:150–3.
    persica. Int Dent J 2004;54:279–83.                                  27. Sreenivasan P, Jayakumar M, Ignacimuthu S. In vitro antibac-
16. Willershausen B, Kasaj A, Sculean A, Wehrbein H. Influence of            terial activity of some plant essential oils. BMC Complement
    a herbal mouthrinse on inflammatory changes of the gingiva in            Altern Med 2006;6:39.
    patients with fixed orthodontic appliances. Periodontal Pract        28. Carvalho CT, Vignolli VV. Antimicrobial activity of essential
    2004;1:255-62.                                                           oils from plants used in Brazilian popular medicine. In: II
17. Sofrata AH, Claesson RK, Lingstorm PK, Gustaffson AK. Strong             WOCMAP congress medicinal and aromatic plants, part 2:
    antibacterial effect of Miswak against oral microorganisms               pharmacognosy, pharmacology, phytomedicine, toxicology,
    associated with periodontitis and caries. J Periodontol                  2006:65–9.
    2008;79:1474–9.                                                      29. Rahmani ME, Radvar M. The antiplaque effects of Salvadora
18. Darout IA, Christy AA, Skaug N, Egeberg PK. Identification and           persica and Padina essential oil in comparison to chlorhexi-
    quantification of some potentially antimicrobial anionic com-            dine in human gingival diseases a randomized placebo
    ponents in Miswak extract. Indian J Pharmacol 2000;32:11–14.             controlled clinical trial. Int J Pharmacol 2005;1:311–15.
19. Almas K, Zeidi ZA. The immediate antimicrobial effect of a           30. Gazi MI, Lambourne A, Chagla AH. The antiplaque effect of
    toothbrush and Miswak on cariogenic bacteria: a clinical                 tooth paste containing salvadora persica compared with
    study. J Contemp Dent Pract 2004;5:105–14.                               chlorhexidine gluconate. Clin Prev Dent 2009;9:3–8.
20. Salehi P, Danaie SM. Comparison of the antibacterial effects of      31. Jenkin S, Addy M, Wade W. The mechanism of action of chlor-
    persica mouthwash with chlorhexidine on streptococcus                    hexidine. A study of plaque growth on enamel inserts in vivo. J
    mutans in orthodontic patients. DARU 2006;14:178–82.                     Clin Periodontol 1988;15:415–24.
21. Razak AF, Othman RY, Rahim ZH. The effect of Piper betle and         32. Moran J, Addy M, Roberts S. A comparison of natural product,
    Psidium guajava extracts on the cell surface hydrophobicity of           triclosan and chlorhexidine mouthrinses on 4 day plaque
    selected early settlers of dental plaque. J Oral Sci 2006;48:71–5.       regrowth. J Clin Periodontol 2009;19:578–83.