Effect of Dissolving Xylitol Chewable Tablets Versus Xylitol Chewing Gum on Salivary pH and Bacterial Count in Geriatric Bedridden Patients : Randomized Clinical Trial
Phase: EARLY_PHASE1
Conditions: Saliva Altered, Plaque
Sponsor: Cairo University

Effect of Dissolving Xylitol Chewable Tablets versus 
Xylitol Chewing Gum on Salivary pH and Bacterial 
Count in Geriatric Bedridden Patients :  
Randomized Clinical Trial 
 
تأثير أقراص 
 الزيليتول الذائبة و القابل  ة للمضغ مقارنة ب
علكة الزيليتول على حموضة 
 اللعاب
والعد البكتيرى مع مرضى الشيخوخة مالزمى الفراش 
 : تجربة اكلينيكية عشوائية
  
Proposal 
Submitted to conservative dentistry department, Faculty of dentistry, 
Cairo University, in partial fulfillment of the requirement for PhD degree 
in Esthetics and Restorative dentistry 
By 
Manar  Abd el-mageed  Ahmed  El-mokanen
 
B.D.S. Cairo University (2012) 
MSC Cairo University (2018) 
  
Supervised by 
Prof.  Mohamed Adel Ezzat 
Professor of Conservative Dentistry, Faculty of dentistry, Cairo University 
 
Dr. Amir Hafez Ibrahim 
Lecturer of Conservative Dentistry, Faculty of dentistry, Cairo University  
 
Dr. Omar Osama Shaalan 
Lecturer of Conservative Dentistry, Faculty of dentistry, Cairo University  
 
Approval  Signature  
Supervisors 
1. 
2. 
3. 
Department Research plan and evidence 
based committee 
1. 
2. 
3. 
4. 
Head of Department 
 
Faculty of Dentistry, 
Cairo University 
(2019) 

1 
 
I) Administrative information  
1) Title: " Effect of Dissolving Xylitol Chewable Tablets versus Xylitol 
Chewing Gum with Geriatric Bedridden Patients on Salivary pH and 
Bacterial Count in Both Saliva &  Interdental Plaque : 
Randomized Clinical Trial" 
2) Trial registration: Trial will be registered in https://clinicaltrials.gov/  
3)  Protocol version:This is the first version of the protocol  (March 2019). 
4) Funding: No funding from any parties 
5) Trial sponsor: Faculty of Dentistry, Cairo University.  
6)  Roles and responsibilities:  
 
Manar Abd el-mageed Ahmed (M.A.) 
Operator, data entry & corresponding author 
Previous resident, Conservative  Dentistry  Department, Faculty  of 
Dentistry, Cairo University, Cairo, Egypt, Postal address: 11 Saraya El 
Manial street Kasr El Einy, Phone:  (002)01287766120, email: 
dentalmena90@gmail.com 
 
Prof.  Mohamed Adel Ezzat (A.E.) 
Main supervisor, data monitoring & auditing; Professor, Conservative 
Dentistry Department, Faculty of Dentistry, Cairo University, Cairo, 
Egypt, email: madelkhairy@yahoo.com 
 
Amir Hafez Ibrahim (A.H.)  
Co-supervisor, data entry & auditing; lecturer,  Conservative  Dentistry 
Department, Faculty of Dentistry, Cairo University, Cairo, Egypt, email: 
amir.hafez@dentistry.cu.edu.eg 
 
Omar Osama Shalaan ( O.S.) 
Co-supervisor, data entry & auditing; Lecturer, Conservative Dentistry 
Department, 
Faculty 
of 
Dentistry, 
Cairo 
University, 
email: 
omar.shaalan@dentistry.cu.edu.eg 
 

2 
 
Hadier Mahmoud Gad( H.M.) & Engy Mostafa Magdy (E.M.) 
Previous resident & demonstrator, Conservative Dentistry Department, 
Faculty of Oral & Dental Medicine Cairo University; outcome assessors 
and data collection. 
 
Yomna Sayed Khallaf (Y.S.)  
Demonstrator, Conservative Dentistry Department, Faculty of Dentistry, 
Cairo University, for baseline data collection, recruitment, sequence 
generation, allocation concealment, patient retention and taking 
participants consents.  
 
Bacteriological Assessment: 
Department of microbiology, Faculty of medicine, Cairo university. 
 
Research Ethics Committee (REC) of Faculty of Dentistry, Cairo 
University; For reviewing protocol of this clinical trial to protect the 
rights, safety, dignity and well-being of the people participating in the 
trial.  
 
Research Plan Committee: 
Conservative Dentistry Department, Faculty of Dentistry, Cairo 
University; for ensuring that this protocol is following the department 
research plan.  
  
 
 
 
 
 
 
 
 
 

3 
 
II. INTRODUCTION 
1) Background and Rationale: 
1.1. Research question:  
For  the  geriatric  bedridden  patients, will the use of the newly 
introduced dissolving Xylitol chewable tablets be better in decreasing  
bacterial count in both saliva and interdental plaque  and elevating the 
salivary pH  if compared  against xylitol chewing gum?  
 
1.2. Statement of the problem: 
Dental caries remains the most prevalent chronic disease in both 
children and adults, and is one of the most common important global 
oral health problems in the world, but it is largely preventable (Yadav 
and Prakash, 2016).  Although caries has significantly decreased over 
the past four decades, disparities remain among some population 
groups like geriatric patients and the scenario becomes even more 
accentuated when it comes to bedridden patients, who are dependent 
and whose functional capacity is shortened. Moreover, they usually face 
the given reality that they are constrained to their rooms, without 
having access to the bathroom which strict their ability for tooth 
brushing and mouth rinsing (Morandi et al, 2018).  
 
1.3. Rationale: 
So, these bedridden patients who may not have ready access to water 
are most need of easy swallowing dosage forms like chewable tablets 
(Renu et al,2015). Using chewable tablets like the newly introduced 
"Listerine Ready Tabs" that can be swallowed give them the 
opportunity to clean their mouth without leaving their beds.  

4 
 
1.4. Review of literature:  
          During the latter half of the 20th century, the age composition of 
the population changed dramatically, with more people living to older 
ages and the older population getting older. This demographic 
change will have a major impact on the delivery of general and oral 
health care. (Abdul razaq, 2014). Improved quality of life at old age will 
demand tooth retention. However, Retaining teeth disease free and 
maintaining preventive care for elderly people, is a multi- faceted 
challenge. (Roopa et al, 2011) 
       Many elderly persons are hampered in their eﬀorts of performing 
plaque control procedures by physical disabilities that result in the lack of 
manual dexterity or impaired range of motion of the wrist, elbow or 
shoulder (Abdul razaq 2014).Moreover, the scenario becomes even more 
accentuated when it comes to bedridden patients as they are constrained 
to their rooms, without having access to the bathroom which strict their 
ability for tooth brushing and mouth rinsing. So, such population must 
take much more interest from us for their oral care.  
     Xylitol, which presents in our interventions , is a naturally occurring 
five-carbon sugar polyol .It is a white crystalline carbohydrate known 
since a century ago. It has been widely studied  during  the last 40 years 
for its effect on dental caries. It is found naturally in fruit, vegetables, and 
berries and is artifacially manufactured from xylan-rich plant materials 
such as birch and beechwood. (Nayak et al, 2014) 
    Xylitol reduces the levels of mutans streptococci (MS) in plaque and 
saliva. It also reduces their acid production potential leading to increase 
in salivary ph. (Nayak et al, 2014) 

5 
 
   It was found that the xylitol bacteriostatic effect on S. mutans  is by 
creating a futile cycle that consumes cellular ATP. In a futile cycle, 
Xylitol is transported across bacterial cell membrane by a phospho-
transferase system, generating xylitol-5-phosphate which can not 
be metabolized and  may  subsequently be dephosphorylated and 
exported at the expense of ribitol-5-phosphate . ( Chen and Wang, 2010) 
Ly et al in 2006 determined the reduction in mutans streptococci 
levels in plaque and unstimulated saliva to increasing frequency 
of xylitol gum use  at  a fixed total daily dose of 10.32 g over five weeks. 
They randomized participants (n = 132) to either active groups (10.32 g 
xylitol/day) or a placebo control (9.828 g sorbitol and 0.7 g maltitol/day). 
All groups  chewed 12 pieces/day. The control group chewed 4 times/day 
and active groups chewed xylitol gum at a frequency of 2 times/day, 3 
times/day, or 4 times/day. The 12 gum pieces were evenly divided into 
the frequency assigned to each group. Plaque and unstimulated saliva 
samples were taken at baseline and five-weeks and were cultured on 
modified Mitis Salivarius agar for mutans streptococci enumeration. They 
found  no significant differences in mutans streptococci level among the 
groups at baseline. At five-weeks, mutans streptococci levels in plaque 
and unstimulated saliva showed a linear reduction with increasing 
frequency of xylitol chewing gum use at the constant daily dose. 
Although the difference observed for the group that chewed xylitol 2 
times/day was consistent with the linear model, the difference was not 
significant. They concluded that there was a linear reduction in mutans 
streptococci levels in plaque and saliva with increasing frequency of 
xylitol gum use at a constant daily dose. Reduction at a consumption 
frequency of 2 times per day was small and consistent with the linear-
response line but was not statistically significant. 

6 
 
Milgrom et al in 2006, determined the dose-response of mutans 
streptococci in plaque and unstimulated saliva to xylitol gum. They 
randomized participants (n = 132): controls (G1) (sorbitol/maltitol), or 
combinations giving xylitol 3.44 g/day (G2), 6.88 g/day (G3), or 10.32 
g/day (G4). Groups chewed 3 pellets/4 times/d. Samples were taken at 
baseline, 5 wks, and 6 mos, and were cultured on modified Mitis 
Salivarius agar for mutans streptococci and on blood agar for total 
culturable flora. They found that  at 5 wks, mutans streptococci levels in 
plaque were 10x lower than baseline in G3 and G4 (P = 0.007/0.003). 
There were no differences in saliva. At 6 mos, mutans streptococci in 
plaque for G3 and G4 remained 10x lower than baseline (P = 0.007/0.04). 
Saliva for G3 and G4 was lower than baseline by 8 to 9x (P = 
0.011/0.038). They concluded that  xylitol  at  6.44 g/day  and 10.32 
g/day reduces mutans streptococci in plaque at 5 wks, and in plaque and 
unstimulated saliva at 6 mos. A plateau effect is suggested between 6.44 
g and 10.32 g xylitol/day. 
Prathibha et al in 2010  compared the effect of Manuka honey, 
chlorhexidine gluconate (0.2%) mouthwash and xylitol chewing gum on 
the dental plaque levels.  Sixty healthy male dental students aged between 
21 and 25 years (mean age 23.4 years) participated in the study. All the 
subjects received a professional prophylaxis at the start of the study, with 
the purpose of making the dentition 100% free of plaque and calculus. 
The subjects were then randomly divided into three groups, i.e. the 
Manuka honey group, the chlorhexidine gluconate mouthwash group and 
the xylitol chewing gum group. Rinsing with water or any other fluid 
after the procedure was not allowed as also any form of mechanical oral 
hygiene for all the subjects during the experimental period of 72 h. After 
the experimental period, the plaque was disclosed using disclosing 

7 
 
solution and their scores were recorded at six sites per tooth using the 
Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. 
They found that the mean plaque scores for Groups I, II and III were 
1.37, 1.35 and 1.57, respectively. The ANOVA revealed that between 
group comparison was significant, with an F-value of 5.99 and a 
probability value of 0.004. The T-test was carried out to evaluate the 
inter-group significance, which revealed that the plaque inhibition by 
Manuka honey was similar to that of chlorhexidine mouthwash. 
So they concluded that both Manuka honey and chlorhexidine 
mouthwash reduced plaque formation significantly, better than the xylitol 
chewing gum. 
Kumar, et al in 2013, evaluated  the  salivary  and dental plaque 
pH changes after consumption of sugared and sugar-free (xylitol) 
chewing gums in children. They selected a total of 30 school children  for 
this study and divided them  into two equal groups and gave  both 
chewing gums for the experiment. They found that children consuming 
the sugar-free (xylitol) chewing gum showed a marked  increase in the 
pH of saliva and plaque when compared to their counterpart. All these 
values had a significant difference of P ≤ 0.0001. So, they concluded that 
xylitol is a safe natural sweetener which helps to reduce tooth decay. 
It plays a unique role in preventive strategies for better health. 
Nishihara et al in 2014 evaluated the effects of the lactic acid 
bacterium Lactobacillus salivarius on caries risk factors. They performed   
their study in 64 healthy volunteers to evaluate the effects of L. 
salivarius-containing tablets on caries risk factors. They divided 
participants  randomly into four groups, and gave them  chewable  tablets 
containing L. salivarius WB21, L. salivarius TI 2711, Ovalgen® DC 
(antibody against glucosyltransferase from Streptococcus mutans), or 

8 
 
xylitol  and then  levels of mutans streptococci and lactobacilli, amount of 
salivary flow, salivary pH, and salivary buffering capacity were assessed 
before and after taking the tablets. They found that the levels of mutans 
streptococci seemed to decrease in the L. salivarius WB21, TI 2711, and 
Ovalgen® DC groups compared to the xylitol group, with no significant 
differences between the groups. Lactobacilli levels significantly increased 
in the L. salivarius WB21 and TI 2711 groups compared to the other 
groups. Concerning salivary flow and salivary pH, they found no 
significant differences between the groups. Also they found that the 
salivary buffering capacity significantly increased in the L. salivarius TI 
2711 group (P = 0.003) and Ovalgen® DC group (P = 0.002) compared 
to the xylitol group. And finally they found that, the L. salivarius WB21-
containing tablets significantly decreased the number of mutans 
streptococci (P = 0.039). 
Lapiedra et al in 2015, evaluated the  effect of a combination 
saliva substitute for the management of xerostomia and hyposalivation 
They evaluated  the difference between the combination agent of xylitol, 
beatine and olive oil in a chewable capsule versus the control agent of a 
sorbitol tablet  in  subjects with hyposalivation and xerostomia . Their 
study was 3 weeks in duration, with 2 treatment phases of 1 week and 
a 7 day wash out period in between. At the end of each treatment phase, 
subjects returned for a follow up evaluation. At this visit they gave the 
patients subjective sensation questionnaire, as well as they measured  
their unstimulated whole salivary flow and stimulated whole salivary 
flow . They found that there was a greater increase in the unstimulated 
and stimulated whole salivary flow rate, although the results were not 
statistically significant. The subjective evaluation as measured by the 
questionnaire showed that both agents reduced the mean score as 

9 
 
compared to the baseline, although only the findings in the active agent 
was statistically significant (p = 0.0015). They concluded that the active 
agent provided a significant subjective improvement in speech, 
swallowing, and decreased subjective xerostomia as compared to the 
control tablet. 
Masoud et al in 2015 evaluated long-term clinical and bacterial 
effects of using 6 g of xylitol per day for 3 months on patients with full 
fixed orthodontic appliances. They made a pilot clinical trial that included 
41 subjects who were undergoing orthodontic treatment. They divided 
subjects randomly into three groups. Group A received xylitol chewing 
gum, group B received xylitol dissolvable chewable tablets, and Group C 
served as the control group and did not receive xylitol gums or tablets. 
Clinical examination and the collection of plaque and saliva samples were 
carried out at baseline and 3, 6, and 12 months. All three groups were 
given oral hygiene instruction and were put on a 6-month cleaning and 
topical fluoride schedule. Plaque scores and bacterial counts were used to 
evaluate the effectiveness of the different approaches at reducing the 
caries risk. They found that xylitol groups did not experience any more 
reduction in plaque score, plaque MS counts, or salivary MS 
counts than the control group nor did they have lower values at any of the 
time points. They concluded that  xylitol does not have a clinical or 
bacterial benefit in patients with fixed orthodontic appliances. Oral 
hygiene instructions and 6-month topical fluoride application were 
effective at reducing plaque scores and bacterial counts in patients with 
full fixed appliances regardless of whether or not xylitol was used. 
Cock et al in 2016 provided a comprehensive overview of 
published evidence on the impact of erythritol, a noncaloric polyol bulk 
sweetener, on oral health. Methods. A literature review was conducted 

10 
 
regarding the potential eﬀects of erythritol on dental plaque (bioflm), 
dental caries, and periodontal therapy. The efficacy of erythritol on oral 
health was compared with xylitol and sorbitol. They found that  Erythritol 
eﬀectively decreased weight of dental plaque and adherence of common 
streptococcal oral bacteria to tooth surfaces, inhibited growth and activity 
of associated bacteria like S. mutans, decreased expression of bacterial 
genes involved in sucrose metabolism, reduced the overall number of 
dental caries, and served as a suitable matrix for subgingival air-polishing 
to replace traditional root scaling. They concluded that important 
diﬀerences  were reported in the eﬀect of individual polyols on oral 
health with the evidence demonstrating better efficacy of erythritol 
compared to sorbitol and xylitol to maintain and improve oral health. 
Swapnil Oza et al in 2018 determined the effect of chewing gum 
containing xylitol and sorbitol on mutans streptococci and Lactobacilli 
count in saliva, plaque, and gingival health and  compared the efficacy of 
chewing gums. They designed as a double-blinded randomized 
uncontrolled clinical trial with two parallel arms. A total of 80 students 
consented and completed the study. The test group (X) received 
corresponding pellets with xylitol and the control group (S) was given 
pellets containing sorbitol and maltitol three times daily for 30 days. 
Clinical scoring and saliva samples were collected at three different 
intervals, at baseline, 15th, and 30th day of the study. The outcome 
measure was plaque index score, gingival index score, salivary mutans 
streptococci, and Lactobacilli counts. They found that there was no 
statistically significant difference between the mean of mutans 
streptococci count of test and control group at baseline and 15th day, but 
there was statistically highly significant difference (P = 0.00) between the 
mean of mutans streptococci count in test and control group on the 30th 

11 
 
day. The mean of Lactobacilli count, plaque index, and gingival index 
score between test and control group showed no statistically significant 
difference at baseline, 15th day, and 30th day. The results suggest that only 
xylitol gum may interfere with the mutans streptococci composition and 
reduce it after continuous use of 30 days effectively as compared to 
sorbitol gum, but both the gums are equally effective on salivary 
Lactobacilli, plaque, and gingiva at different intervals. 
Rafeek et al in 2019, conducted a study to see if chewing gum 
containing  xylitol  may  help  prevent  caries by reducing levels of 
mutans streptococci (MS) and lactobacilli in saliva and plaque. In this 
study, they employed high-throughput sequencing of the 16S rRNA gene 
to profile microbial communities of saliva and plaque following short-
term consumption of xylitol and sorbitol containing chewing gum. 
Participants (n = 30) underwent a washout period and were randomly 
assigned to one of two groups. Each group chewed either xylitol or 
sorbitol gum for three weeks, before undergoing a second four-week 
washout period after which they switched to the alternate gum for three 
weeks. Upon analysis of samples collected before and after each 
intervention, they identified distinct plaque and saliva microbial 
communities that altered dependent on the order in which gum treatments 
were given.They found that  neither the xylitol nor sorbitol treatments 
significantly affected the bacterial composition of plaque. Lactobacilli 
were undetected and the number of Streptococcus mutans sequence reads 
was very low and unaffected by either xylitol or sorbitol. However, 
sorbitol affected several other streptococcal species in saliva including 
increasing the abundance of S. cristatus, an oral commensal shown to 
inhibit bacteria associated with chronic periodontitis. 

12 
 
1.5. Choice of comparator:  
        In our study , the comparator is xylitol chewing gum as Nayak et al 
in 2014  mentioned  that  the predominant modality for xylitol delivery 
has been chewing gum, as moreover the antibacterial  effect of xylitol , 
chewing a gum accelerates the processes of rinsing away acid by 
stimulating salivary flow and uptake of benefacial calcium phosphate 
molecules to remineralize tooth enamel. ( Chen and Wang, 2010) 
      And another special cause in this  study is  our population who are 
geriatric bedridden patients. As chewing a soft gum is a simple, easy, 
convenient  independent procedure that don't need any physical effort or 
caregiver and also don't need from them to leave their beds or to go to the 
bathroom like for brushing or rinsing. 
2) Objectives:  
2.1. Aim of the study: 
This study will be conducted to evaluate  the effectiveness of using 
dissolving  Xylitol  chewable tablets versus xylitol chewing gum with 
bedridden  geriatric patients  ,as an alternative to tooth brushing and  
mouth rinsing,  in  increasing  salivary  pH  and  decreasing bacterial 
count in both saliva and interdental plaque. 
2.2. Hypothesis:  
The null hypothesis is that the newly introduced dissolving xylitol 
chewable tablets have the same effect as xylitol chewing gum on salivary  
pH  and  bacterial  count  in  both  saliva and interdental plaque when 
used with geriatric bedridden patients.  
 
 

13 
 
2.3. Primary and secondary objectives:  
PICOTS  
P (problem /population):  geriatric bedridden patients 
I (intervention /indicator): dissolving Xylitol chewable tablets "listerene 
ready tabs" 
C (control /comparator):  xylitol chewing gum "Trident original" 
O (outcome) : 
O1: salivary streptococcus mutans count 
O2: interdental plaque bacterial count 
O3: salivary pH 
 
T (time): 
T0: Baseline 
T1: 5 minutes   
T2: 15 days 
S (study): randomized clinical trial. 
 
2) Trial design:  
Randomized clinical Trial, parallel arms.  
Trial framework: Equivalence frame 
Allocation ratio: 1:1.  
Measuring Unit 
Measuring Device 
Outcome Name 
Type 
CFU/ml 
Bacterial Culture 
Salivary S.mutans count 
1ry 
CFU/ml 
Bacterial Culture 
Interdental plaque 
Bacterial count 
2ry 
Moles per litre 
pH Meter 
Salivary  pH 
3ry 

14 
 
III. METHODS 
A) Participants, interventions, & outcomes 
1) Study Settings:  
This clinical trial will be held in the Faculty of medicine, Cairo  
University, Egypt.  
2) Eligibility criteria: 
a- Eligibility criteria of participants : 
 
 Inclusion Criteria :  
(1) Age range above 65 years old 
(2) Bedridden patients 
(3) Males or females 
(4) Concious patients 
(5) Co-operative patients approving to participate in the trial. 
(6) Subjects who signed informed consent 
 Exclusion criteria: 
(1) Individuals had taken antibiotics during the last four weeks or 
anticipated doing so during the study 
(2) Subjects who wore removable prosthesis 
(3) Patients with systemic diseases that have any oral manifestations 
(4) History of Smoking 
(5) Allergy to any of chewing gum or tablets ingredients 
(6) Evidence of tempromandibular joint disorders 
(7) Presence of intraoral infections 
(8) Currently using any mouth rinse 
 
b- Assessors and operator criteria:  
Operator: M.A. (Master degree), 
Assessors: H.M. (Master degree), E.M.  (Master degree).  

15 
 
3) Interventions: 
In our study, we selected for both intervention and comparator, materials  
that  don't  need  from those geriatric bedridden patients to leave their 
beds with both materials are xylitol containing materials but with 
different delivery system. The intervention is  dissolving  xylitol 
chewable tablets and the comparator is xylitol chewing gum. 
The intervention is the newly introduced dissolving xylitol chewable 
tablets " Listerine Ready Tabs " .Technically, it’s a rectangular-shaped, 
bilayer-compressed tablet that once chewed, creates just enough liquid to 
swish around your mouth to get a whole-mouth clean feeling. As 
manufacture claimed the tablet is easy to use just in three simple steps: 
chew (to activate),  swish  (to clean), then swallow as unlike 
mouthwashes which may contain alcohol and other ingredients not 
intended for ingestion, Listerine Ready Tabs are alcohol-free and safe to 
swallow which is highly suitable for bedridden patients. It's composed  
of Xylitol, Erythritol, Isomalt, Calcium Carbonate, Flavor, Magnesium 
Stearate, Cellulose Gum, Hydroxypropyl Cellulose, Tetrasodium 
Pyrophosphate, PVP, Sucralose, Acacia Senegal Gum, Potassium 
Acesulfame, Glycerin, and Potassium Sorbate. Moreover the beneficial 
effect of xylitol ,as mentioned before, the addition  of  Erythritol  in  its 
composition adds more value for the tablets as all studies strongly 
support the idea of erythritol as a caries-reducing dietary polyol with 
inhibitory effect on  the growth of certain mutans streptococci isolates by  
a mechanism of growth inhibition differs from that caused by xylitol. 
Morover, combinations of erythritol and xylitol will turn out to exert 
promising caries-limiting effects in humans as the combined effects may 
exceed or at least equal the separate effects of both polyols. (Makinen, 
2010) 

16 
 
The comparator is Original Trident which is  a soft gum sweetened with 
xylitol . It also contains  sorbitol, Mannitol, Aspartame, Sucralose and 
Acesulfame potassium.  
For our methodology, the saliva and the dental plaque samples will be 
collected along the previously determined timeline; T0: before taking 
either the intervention or the comparator and T1:  immediately  after 
5min and T2: 15days (for salivary ph measurement and bacterial count 
in both saliva and interdental plaque). 
 For Intervention group: 
Participants   had to take one tablet three times per day, taken orally, after 
eating. Participants will  be directed to chew the tablet (to activate),  
swish  (to clean), then swallow it . They were  not to take other probiotic 
products or mouth rinse throughout  the study period. Neither 
professional prophylaxis nor tooth brushing instruction will be performed 
before or during the experimental period. (Nishihara et al, 2014) 
 For Comparator group: 
Participants were instructed to chew the gum three times daily after 
eating for 5 min (Swapnil et al, 2018).Also ,like the intervention group, 
they were  not to take other probiotic products or mouth rinse  throughout  
the study   period and  neither  professional prophylaxis nor tooth 
brushing instruction will be performed .(Nishihara et al 2014). 
 Salivary sampling: 
On the day of saliva collection, subjects were instructed not to eat or 
drink anything for at least 1 hour before the collection of saliva sample. 
The participants were asked to rinse their mouth with water before 

17 
 
collection of saliva to avoid the contamination of food debris. Then, 
subjects were instructed to let saliva collect without swallowing for at 
least 1 min, and then to expectorate into sterile graduated    collection 
tube with the help of a sterile funnel. The collected saliva will be divided 
into two parts :  first; at least 2 ml for  ph measurement and second; the 
remaining salivary sample was transferred into 5-ml sterile disposable 
vials and carried in a vaccine carrier with freezing mixture to the 
laboratory, where analysis of the sample was done on the same day. 
(Swapnil et al, 2018) 
 Plaque Sampling: 
Interdental  plaque samples were collected from mesial and distal 
surfaces  with  the help of a sterile spoon excavator. These plaque 
samples were then dispersed in a test tube containing double de-ionized 
distilled water. (Kumar et al 2013) 
 Salivary ph measurement: 
The pH  values were  assessed  with  the help of a pH meter . The 
required minimum  volume  of  saliva  is 2 ml  in a sterile test tube so that 
the bulb of the measuring electrode could dip sufficiently into the saliva 
samples. Then, collected samples will be then subjected for the pH 
measurements. (Kumar et al 2013)  
 Culture of mutans streptococci: 
The saliva and plaque sample was homogenized by shaking in a vortex  
for 30 s to disperse bacterial aggregates. Hundred microliter of saliva and 
plaque were diluted with 1 ml of sterile peptone water to obtain 1:10 
dilution of both saliva and plaque. About 100 μl of the diluted saliva and 
plaque was further added to 1 ml of sterile peptone water to obtain a 

18 
 
dilution of 1:100. This procedure was repeated to obtain a dilution of 
1:1000. This dilution was used for microbial analysis. S. mutans will be 
cultured on mitis salivarius-bacitracin (MSB) agar. The media will  be  
prepared according to the manufacturer's instructions and poured into 
sterile disposable microbial culture plates and refrigerated till inoculation 
is done. Under strict aseptic conditions , 5 μl aliquots of each dilution will 
spread using micropipette  onto MSB solid media and sterile glass rod 
will be used to give homogenous bacterial growth. The MSB agar plate 
will be incubated for 48 h at 37°C, anaerobically in an atmosphere of 5% 
CO2 using candle jar. After 48 h of incubation period, S. mutans will 
appear on the culture plate as small, rough, raised, and adherent colonies. 
Colonies so identified will be counted by a single examiner, who will be 
unaware  of  the treatment of the patients. (Swapnil et al, 2018) 
1)  Outcomes: (Table 1)  
 
Methods of aggregation 
 
 
type 
Criteria 
score 
Outcome Name 
No. 
 
Absolute risk will be 
reported for each 
intervention 
independently. Relative 
risk will be used to 
compare both 
interventions with 95 % 
CI. 
 
 
 
Categorical 
ordinal 
102  cfu/ml 
103 cfu/ml 
104 cfu/ml 
105 cfu/ml 
VL: very low 
L: low 
M:Moderate 
H:High 
Salivary 
S.mutans count 
1ry 
Interdental 
plaque Bacterial 
count 
2ry 
Swapnil et al, 2018 
 
 
 
Mean and Standard 
deviation 
  
 
 Continous 
Normal 
salivary ph 
 = 
6.2 - 7.6 
Numerical 
values 
Salivary ph 
3ry 
Baliga et al,2013 

19 
 
2) Participant timeline: (Table 2) 
 
 
3) Sample size calculation: 
 
A power analysis was designed to have adequate power to apply 
statistical test of the research hypothesis that dissolving xylitol chewing 
tablets will have the better antibacterial effect than xylitol chewing gum 
against mutans streptococci after 1 month. According to the results of  
Swapnil et al. in 2018 in which the probability of bacterial count 
reduction to 102 for xylitol chewing gum (comparator) was (0.15), 
probability of bacterial count reduction to 103  was (0.6) and probability 
of bacterial count reduction to 104  was (0.25) with effect size w=0.578 
(n=29). If the estimated probability of dissolving xylitol chewing tablets 
for bacterial count reduction to 102 is (0.35), probability of bacterial 
count reduction to 103 is  (0.5) and probability of bacterial count 
Activity 
Staff 
member 
T0 
Baseline 
 
T1 
After 5  
min 
T2 
After 15   
days 
Recruitment 
Y.S. 
X 
 
 
Diagnosis 
Y.S. 
X 
 
 
Consent 
Y.S. 
X 
 
 
Baseline data 
 collection 
Y.S. 
X 
 
 
Randomization 
Y.S. 
X 
 
 
Saliva & 
Plaque sampling 
M.A. 
X 
X 
X 
Outcome 
assessment 
H.M. 
E.M. 
X 
X 
X 

20 
 
reduction to 104  was (0.15)  with effect size w= 0.43 (n=53). By adopting 
an alpha (α) level of 0.05 (5%), power=80%. The predicted sample size 
(n) was a total of (82). Sample size was increased by (20%) to account for 
possible dropouts during follow-up intervals to be total of (98) cases i.e. 
(49) for each group. Sample size calculation was performed using 
G*Power 3.1.9.2. 
4) Recruitment:  
Patients will be recruited by Y.S from intensive care units in kasr el Ainy 
hospitals, Faculty of Medicine, Cairo University, where there is a 
continuous and high patient flow from which eligible patients will be 
recruited to fulfill the eligibility criteria . 
B) Assignment of interventions (Allocation):  
1) Sequence generation:  
Simple randomization will be done by generating numbers from 1:98 
using Random Sequence Generator, Randomness and Integrity Services 
Ltd (https://www.random.org/) by Y.S. Each generated random number 
will represent assigning intervention and comparator in a random 
manner, i.e.: No. 1 intervention No.2 comparator.  
 
2) Allocation concealment:  
Operator M.A. will choose between numbers in an opaque sealed 
envelope, which will be arranged by Y.S. who will not be involved in 
any of the phases of the clinical trial. Data will be recorded on a 
computer by M.A. and  H.M. and all records of all patients will be kept 
with the main supervisor A.E.  
 
 

21 
 
3) Implementation: 
Y.S. will generate the allocation sequence, enroll participants ,and assign 
participants to interventions. 
4) Blinding:  
The operator will be blinded to material  and  assessors H.M. & E.M. 
will be blinded to the material assignment.  
 
C) Data collection, management, and analysis: 
1)  Data collection methods:  
1.1. Baseline data collection: 
For every  patient medical and dental history will be taken.          
Examination     charts will be filled by Y.S.                         
1.2. Outcome data collection:  
Outcomes will be evaluated by two assessors H.M. & E.M. before 
interventions, after 5 minutes and 15 days, if both assessors differ in 
score, they will discuss, if did not agree a third assessor will resolve the 
conflict.  
1.3. Patient retention:  
The phone number of the patient or his/her caregiver will be recorded 
in the patient's chart. The patient will receive a phone call by Y.S. to 
remind him of the time of the operator  M.A. visit for saliva and plaque 
sampling. Moreover, patients will receive a daily phone message in the 
time assigned  for chewing either the gum or the tablet.    
2) Data management:  
Data entry will be accomplished by M.A. & revised by E.M. All data will 
be stored on computer and will be encrypted using a password. This is 

22 
 
done to allow accurate data entry thorough revision and protect data from 
being inadvertently used. Data will be backed up on another computer to 
prevent it from being lost.  
3) Statistical methods:  
Data will be analyzed using IBM SPSS advanced statistics (Statistical 
Package for Social Sciences), version 25 (SPSS Inc., Chicago, IL). 
Categorical data will be described as absolute risk for each intervention 
independently and relative risk when comparing both interventions. 
Comparisons between categorical variables will be performed using the 
chi square test and Kruskal Wallis will be used to test interaction of 
variables. Continuous data will be described using mean and standard 
deviation. Comparison between continuous data will be performed using 
t-test and two-way ANOVA will be used to test interaction of variables. 
A p-value less than or equal to 0.05 will be considered statistically 
significant and all tests will be two tailed. 
D) Monitoring:  
1) Data monitoring:  
The main supervisor (A.E.) will monitor this study. His role is to monitor 
any risk of bias from participants, operator or assessors, monitor blinding 
of the assessors and monitor patient safety, outstanding benefits or harms.  
2) Harms:  
No Harms  are  expected. But if any adverse effect occurs then the senior 
supervisor has the right to call for stopping the trial if more than 30% of 
cases showed any harms or side effects. 
 

23 
 
3)Auditing:  
In this trial auditing will be done by the main and co-supervisors (A.E., 
A.H. & O.S.) to assure quality of the research methods, sampling 
techniques and interventions.  
IV) ETHICS AND DISSEMINATION: 
1) Research ethics approval:  
Application forms for accomplishing clinical trial, checklist and informed 
consent of Research Ethics Committee (REC) Faculty of Oral and Dental 
Medicine, Cairo University will be retrieved and filled, then will be 
delivered for REC committee for approval, this is done to prevent any 
ethical problems during the study or any harms for any of the 
participants. 
  
2) Protocol amendments:  
If a new protocol will be used a protocol amendment will be submitted, 
containing a copy of the new protocol and a brief explanation about the 
differences between it and the previous protocols. If there is a change in 
the existing protocol that affect safety of subjects, investigation scope, or 
scientific quality of the trial an amendment containing a brief explanation 
about the change must be submitted. If a new author will be added to 
accomplish the study an amendment including the investigator’s data and 
qualifications to conduct the investigation will be submitted to prevent 
ghost authorship.  
3) Consent or assent:  
Y.S. is responsible  of admitting and signing the informed consents 
during enrollment day.  

24 
 
4) Confidentiality:  
The name and the personal data of the participants will not appear on the 
protocol form and should be maintained secured for 10 years after the 
trial. This is done for protection of participants' privacy and civil rights.  
4) Declaration of interests:  
There is no conflict of interest, no funding or  material supplying from 
any parties.  
5) Access to data:  
Access to final data will be allowed to M.A. and the main and co-
supervisors (A.E., A.H.  & O.S.) who are not involved in assessment of 
the outcome.  
6) Ancillary and post-trial care:  
Patients will be followed up after the end of the study period to ensure 
oral hygiene measures.  
7) Dissemination policy:  
• Full protocol will be published online in https://clinicaltrials.gov/ 
to avoid repetition, and keep the integrity of the research work.  
• Thesis will be discussed in front of a judgment committee.  
• The study will be published to report the results of the clinical trial.  
V) APPENDICES:  
Informed Consent Model of (REC) Faculty of Dentistry, Cairo 
University will be used in this study.  

25 
 
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