Evaluation of Toothbrush Bristles in Reduction of Plaque, Inflammation, Bleeding, and Abrasion: A Comparative Study of Tapered vs. End-Rounded Bristles
Phase: NA
Conditions: Gingivitis and Periodontal Diseases
Sponsor: State University of New York at Buffalo

 
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Study Protocol 
 
 
 
 
 
 
 
 
Evaluation of Toothbrush Bristles in Reduction of Plaque, 
Inflammation, Bleeding, and Abrasion: A Comparative 
Study of Tapered vs. End-Rounded Bristles 
 
 
 
 
 
 
 
Principal Investigator: Dr. Marcelle Nascimento 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
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Sponsor : Sunstar Americas, Inc. 
 
I. 
INTRODUCTION  
 
Toothbrushes with tapered bristles were designed to clean plaque accumulated interdental area 
effectively. In vitro studies showed that the effectiveness in artificial plaque reduction is greater 
than that of the conventional toothbrushes with end rounded bristles. However, clinical studies in 
dental plaque and gingivitis have not showed consistent results in the superiority compared to 
conventional toothbrushes1)-3). The purpose of this randomized, examiner blind, parallel controlled 
clinical research is to evaluate the cleaning efficacy of toothbrushes tufted with tapered bristles and 
end rounded bristles in removal of interdental plaque using three clinical endpoints, Plaque Index 
(PI), Bleeding on Probing index (BOP) Periodontal Probing Depth (PPD), Clinical Attachment 
Loss (CAL), and Gingival Abrasion Score. This study will demonstrate the influence of a type of 
processing bristles on removal of interdental plaque and reduction of inflammation and determine 
an agreement between the different evaluation methods.  
 
 
II. 
STUDY OBJECTIVES  
 
The objective of this study is to evaluate and compare toothbrushes with two different bristle types 
in the reduction of plaque index (PI), inflammation, Bleeding on Probing index (BOP), Periodontal 
Probing Depth (PPD), Clinical Attachment Loss (CAL), and Gingival Abrasion Score for 
interdental area. 
 
III. 
STUDY GROUPS 
 
Two different bristles will be tufted into the same tuft pattern. All toothbrush head and handle are 
identical. The study samples will be provided by a sponsor. The bristle dimensions (height, base 
diameter of filament) will be same. The difference between the two toothbrushes is the type of 
processing bristles. 
 
Product A:  Double Tapered J-hook bristles (GUM® Technique® Deep Clean Toothbrush, 525 
TPA1) 
Product B:  End rounded bristles: The same handle/head design as the Product A  
 
Table 1. Physical characteristics of the bristles in all test groups  
 
 
 
 
 
 
 
 
 
Product A 
Product B 
Name 
Double tapered J-hook (DTJ) 
End rounded (Control) 
Individual filament heights in all tufts 
10 and 13 mm 
10 and 10 mm 
Tall filament end 
Chemically tapered 
Rounded 
Short filament end 
Chemically tapered 
Rounded 
Filament’s base diameter, milli inch (mm) 
7 (0.18) 
7 (0.18) 
Filament material 
PBT 
Nylon 

 
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IV. 
SUBJECT INFORMATION AND CONSENT 
 
The clinical investigation, including the consent form, will be reviewed by an IRB in accordance 
with Title 21 of the Code of Federal Regulations, Parts 50 and 56.  Subject consent will be obtained 
prior to participation in any study procedures as required by the Food and Drug Administration 
(FDA) GCP guidelines. Subjects will be given ample opportunity to read the consent form and have 
all questions about study conduct answered before signing and dating the consent form.  Each 
subject will be provided with an exact copy of the informed consent form to retain for his or her 
records. 
Informed consent means the knowing consent of an individual, so situated so as to exercise free 
power of choice without undue inducement or constraint or coercion. The elements of information 
necessary for such consent include: a statement that the study involves research; an explanation of 
the procedures to be followed and their purpose; identification of any procedures that are 
experimental; any expected discomforts, risks or benefits; approximate number of subjects 
involved in the study; any appropriate alternative procedures or treatments; description of the 
confidentiality of subject records; name and phone number of the individual to contact with 
inquiries concerning the research; explanation of compensation or free medical treatment available 
for research-related injury; statement that the subject is free to withdraw consent and to discontinue 
participation at any time; statement that participation is voluntary; indication of any additional costs 
to the subject; assurance that the subject will be notified of new findings relevant to the subject’s 
participation; statement that it is within the Principal Investigator’s discretion to drop the subject 
from participation at any time. 
In addition, the agreement entered into by the subject should include no exculpatory language by 
which the subject is made to waive, or appear to waive, any of his/her legal rights or to release the 
institution from liability or negligence. 
 
V. 
SUBJECT POPULATION 
 
Sample Size Calculation 
The sample size was calculated to detect a 10% difference between the study groups, assuming 
mean baselines of 0.45 units in plaque scores and a standard deviation (SD) of 0.06. With a 
significance level (α) of 0.05 and a power of 80%, the estimated sample size is 29 participants per 
group. To account for an estimated dropout rate of 15%, the adjusted sample size is 
35 participants per group, and a total sample size of 70 participants. 
 
Volunteers must read and sign the Informed Consent Form after the nature of the study has been 
fully explained.  
 
Inclusion Criteria 
Individuals may be included in the study provided they meet all of the following inclusion 
criteria: 
  

 
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• Must have read, understood and signed an informed consent prior to being entered into the 
study. 
• Must be 18 to 70 years of age, male or female.  
• Have at least 20 natural or restored teeth, not including implants.  
• Must have average Plaque Index of Rustogi Modification teeth greater than 2 (Navy PI) at 
screening.  
• Must have more than 20% of pockets with bleeding on probing at screening. 
• Agree not to have a dental prophylaxis or any other elective, non-emergency dental procedures 
(other than those provided during the study) any time during the study. 
• Agree to refrain from regular oral hygiene regimen for 24 hours and eating for 4 hours before 
the appointment in the study. 
• Agree to abstain from the use of any dental products other than those provided in the study.  
• Agree to comply with the conditions and schedule of the study. 
 
Exclusion Criteria 
 Individuals are not eligible for participation in this study if any of the following are noted:  
 
• Physical limitations or restrictions that might preclude normal tooth brushing. 
• Evidence of gross oral pathology 
• Periodontal probing pocket depths (PPD) ≥ 5mm. 
• Evidence of major soft tissue lesions or trauma at the baseline visit as determined by the 
Investigator/Examiner. 
• Chronic disease with concomitant oral manifestations 
• Subjects who are currently undergoing, or require, extensive dental work, orthodontic treatment 
or periodontal surgery or orthodontic treatment in the preceding 3 months 
• Currently using bleaching trays 
• Eating disorders 
• Recent history of substance abuse  
• Smoking >10 cigarettes/day  
• Participation in other clinical studies within 14 days of screening 
• Pregnancy  
 
VI. 
STUDY DESIGN OVERVIEW 
 
This parallel group, examiner blinded, randomized, single center study will enroll 70 subjects to 
target 58 subjects completing the study. Subjects will visit the clinical site 4 times including a 
screening visit, and if eligible, 3 additional study visits. Subjects will be instructed to refrain from 
regular oral hygiene regimen for 24 hours and from eating for four hours before each appointment. 
The study examiner and staff will screen for subjects that meet the enrollment criteria. Eligible 
subjects will be randomly assigned to one of two treatment groups.  
 
• Group 1:  Product A – 35 participants 
• Group 2:  Product B – 35 participants 
 
After distribution of an assigned test toothbrush, subjects will receive a basic brushing instruction 
for Bass method by a study staff but without actual brushing. Subjects will perform toothbrushing 

 
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using the assigned product for 2 minutes under supervision. Plaque Index (Navy PI), Bleeding on 
Probing (BOP Index), Periodontal Probing Depth, Clinical Attachment Loss, and Gingival 
Abrasion Score will be taken before/after the one-time brushing. Photos will be taken before and 
after brushing.  
 
Subjects will use the assigned toothbrush for the whole study. Subjects will be evaluated for their 
Gingival Abrasion Score, BOP, and PI, PPD and CAL every study visit. The study schedule is 
shown in Table 2. Adverse experiences will be noted and recorded during the study. 
 
Patients who are fully compliant to the clinical trial protocol should enter the primary analysis. 
           
 
Table 2. Summary of Study Visits 
Events 
 
Visit 1 
Eligibility 
Screening 
Visit 2 
Week 0 
Visit 3 
Week 2 
Visit 4 
Week 4 
Informed consent, demographics, Inclusion/Exclusion 
criteria, medical history, concurrent meds 
 
X 
 
 
 
Update of Inclusion/Exclusion criteria 
 
X 
X 
X 
Photos (3 front, left, and right side of mouth)  
 
X 
 
X 
Clinical Measurements for inclusion/ exclusion (PD, 
BOP, PI) 
X 
 
 
 
Clinical endpoints (Gingival Abrasion, BOP, PI, PPD 
and CAL)  
 
X 
X 
X 
Repeat clinical endpoints and photos before and after 
brushing 
 
X 
 
X 
Test product distribution 
 
X 
 
 
Instruction of brushing  
 
X 
 
 
Reminder call/text 
 
X 
X 
X 
Compliance check 
 
 
X 
X 
Adverse events 
 
X 
X 
X 
 
 
 

 
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VII. 
CLINICAL SUPPLIES 
 
Test Materials 
The sponsor will provide the following items to the study site:  
• 2 test toothbrushes with different types of bristles (A, B) 
• Toothpaste throughout the study period 
 
Packaging and Labeling 
 
The toothbrushes will be recognized as a different type. 
 
Delivery and Inventory:   
 
Immediately upon receipt of study supplies at the clinical site, study personnel will account for all 
products. The study staff is responsible for maintaining the inventory log. 
 
Storage:   
 
Study supplies will be maintained under secure conditions, until assignment to subjects.  
 
Return of Study Supplies:  
 
At the conclusion of the study, all unused products will be returned to the Sponsor.   
Used products will also be returned to the Sponsor. 
 
 
VIII. TREATMENT REGIMEN 
 
Qualified subjects meeting all inclusion and exclusion criteria will be provided with their 
assigned toothbrush (A or B) at Visit 2. Subjects will be instructed to brush their teeth as 
instructed with their assigned toothbrush 2 times daily (after breakfast, before going to bed) for 2 
minutes, using only the provided toothpaste at Visit 2.  
 
The same fluoride toothpaste will be used throughout the whole study period. Subjects will 
refrain from using other oral hygiene products such as interdental brush, floss, or antimicrobial 
mouthwash throughout the study period.  
 
 
IX. 
PRODUCT USE COMPLIANCE  
 
Product compliance will be monitored by phone calls and/or text messages to the participants to 
remind them to use the product following the instructions given. 
 
X. 
RESTRICTIONS 
 
Subjects will be advised of the following restrictions during the study period: 

 
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• To avoid using other oral hygiene products such as interdental brush, floss, or antimicrobial 
mouthwash throughout the study period.  
• To avoid starting or changing treatments, medications including OTC drugs and supplements that 
potentially modify plaque accumulation for the duration of the study. 
• To refrain from starting or changing habits (e.g. eating chewing gum) to potentially modify 
subject’s plaque accumulation condition for the duration of the study.  
 
 
XI. 
STUDY PROCEDURES  
 
Pre-Screening Phone Call 
As part of the recruitment and screening process, individuals interested in participating in the 
study will contact the clinical research center. A follow-up phone call will be conducted using a 
standardized script to: 
• Confirm that the participant meets the inclusion and exclusion criteria. 
• Schedule the screening visit, and assess participant’s availability for the other 3 study 
visits. 
• Provide pre-screening instructions: refrain from toothbrushing for 24 hours and eating for 
at least 4 hours prior to Visit 1. 
Reminder Phone Calls and Text Messages (24-48 hours prior to each visit) 
For Visits 1 through 4, participants will receive a reminder phone call and text message 24 to 48 
hours before their scheduled appointment. During this call, study staff will: 
• Confirm the date and time of the upcoming visit. 
• Review any updates or changes in the participant’s medical and dental history. 
• Remind participants of study instructions, including brushing behavior and adherence to 
study restrictions. 
• Remind participants of the following pre-visit instructions: refrain from toothbrushing for 
24 hours and eating for at least 4 hours prior to the visit. 
 
Screening Visit 1  
During the screening, Visit 1, the following procedures will be conducted: 
1. Obtain written informed consent from all participants. 
2. Confirm eligibility by reviewing inclusion and exclusion criteria. 
3. Collect baseline data via questionnaires, including demographic information, medical history, 
dental history, and current medication usage. 
4. Take blood pressure measurement. 
5. Perform assessments to determine clinical eligibility: 
o Periodontal Probing Depths (PPD) 
o Bleeding on Probing (BOP) 

 
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6. Apply plaque disclosing solution to teeth and assess Plaque Index (PI)    
7. Record eligibility status based on PI (>2) and BOP (>20%) and PPD (< 4mm). 
8. Complete urine pregnancy test for women of childbearing age, if applicable. 
9. Confirm availablity for 3 study visits and schedule remaining visits. 
Visit 2 (Week 0) 
During Visit 2, the following procedures will be conducted: 
1. Review and confirm inclusion and exclusion criteria. 
2. Update the participant’s medical history and current medications       
3. Assess and document any adverse events since the last visit.                       
4. Take blood pressure measurement. 
5. Take pre-staining intraoral photographs (frontal, left, right views). 
6. Apply plaque disclosing agent to stain hard and soft tissues. 
7. Take photographs following plaque disclosure, prior to brushing. 
8. Perform whole-mouth clinical assessments and record findings: 
o Plaque Index (PI) 
o Bleeding on Probing (BOP) 
o Gingival Abrasion Score  
o Periodontal Probing Depths (PPD) 
o Clinical Attachment Loss (CAL) 
9. Randomize eligible participants to one of two treatment groups using a computer-generated 
permuted block randomization sequence, ensuring balanced group sizes. 
10. Distribute the assigned toothbrush and toothpaste to participants. 
11. Provide standardized brushing instructions using the Bass method using a mouth model and 
regular toothbrush. 
12. Supervise a 2-minute brushing session using the assigned toothbrush and a half-inch length of 
toothpaste. 
13. Apply plaque disclosing agent again to stain hard and soft tissues. 
14. Take post-brushing intraoral photographs (frontal, left, right views). 
15. Repeat clinical assessments (PI, BOP, Gingival Abrasion Score) following brushing to assess 
immediate effects. 
16. Assess and document any adverse events. 
17. Confirm the schedule of the next visit within 14 ± 2 days and review pre-visit instructions. 
 

 
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Visit 3 (Week 2) 
During Visit 3, the following procedures will be conducted: 
1. Review and confirm inclusion and exclusion criteria. 
2. Update the participant’s medical history and current medications. 
3. Compliance check for study instructions, including brushing behavior and adherence to study 
restrictions. 
4. Assess and document any adverse events since the last visit. 
5. Take blood pressure measurement. 
6. Apply plaque disclosing agent to stain hard and soft tissues. 
7. Perform whole-mouth clinical assessments and record findings: 
o Plaque Index (Navy PI) 
o Gingival Abrasion Score 
o Bleeding on Probing (BOP) 
o Periodontal Probing Depths (PPD) 
o Clinical Attachment Loss (CAL) 
8. Provide each participant with a new supply of fluoride toothpaste. 
9. Confirm the schedule of the next visit within 14 ± 2 days and review pre-visit instructions. 
 
Visit 4 (Week 4) 
During the final visit, the following procedures will be conducted: 
1. 
Review and confirm inclusion and exclusion criteria. 
2. 
Update the participant’s medical history and current medications. 
3. 
Compliance check for study instructions, including brushing behavior and adherence to study 
restrictions. 
4. 
Assess and document any adverse events since the last visit. 
5. 
Take blood pressure measurement. 
6. 
Take pre-staining intraoral photographs (frontal, left, right views). 
7. 
Apply plaque disclosing agent to stain hard and soft tissues. 
8. 
Take photographs following plaque disclosure, prior to brushing. 
9. 
Perform whole-mouth clinical assessments and record findings: 
o Plaque Index (PI) 
o Bleeding on Probing (BOP) 

 
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o Gingival Abrasion Score 
o Periodontal Probing Depths (PPD) 
o Clinical Attachment Loss (CAL) 
10. Supervise a 2-minute brushing session using the assigned toothbrush and a half-inch length of 
toothpaste. 
11. Apply plaque disclosing agent again to stain hard and soft tissues. 
12. Take post-brushing intraoral photographs (frontal, left, right views). 
13. Repeat clinical assessments (PI, BOP, Gingival Abrasion Score) following brushing to assess 
immediate effects. 
14. Complete the study completion/exit form, including participant signature for compensation. 
15. Distribute and document the issuance of the gift card/payment card as compensation. 
 
 
XII.   ADVERSE EXPERIENCES 
 
Adverse Event Definition and Handling 
An adverse event is any unexpected or serious medical occurrence in a clinical investigation subject 
during the study, whether or not related to the study product.  All adverse events observed by the 
investigator and/or reported by the subject will be recorded throughout the entire study and 
documented. The Investigator will be asked to make a judgement on all adverse events as to their 
severity and possible relation to the study treatments. 
 
 
More specifically, adverse events would include: 
• Any unexpected event not seen before study initiation. 
• Any pre-existing event that recurs with increased intensity or increased frequency 
subsequent to initial product treatment. 
 
Adverse events will be reported to the investigator and the sponsor will be notified within 24 
hours of any serious adverse events.  All adverse events should be recorded on the appropriate 
case report form, including date of onset, severity, duration, treatment, and follow-up observation.  
The following definitions will be used for grading severity of adverse events:  
• Mild - Either asymptomatic, or subject is aware of the sign, symptom, or event, but it is 
easily tolerated. 
• Moderate - Discomfort enough to cause interference with usual activity and may warrant 
intervention.  
• Severe - Incapacitating with inability to do usual activities.  
 
The investigator will make an assessment of the likelihood that there is a reasonable possibility of 
a causal relationship between a study product and the adverse event. This will be captured using 
the following criteria: product related, non-product related, non-product related but protocol 
related. The causal relationship to the product will be assessed as: definitely related, probably 

 
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related, possibly related, probably not related, or definitely not related. 
 
Serious Adverse Event  
A serious adverse event is any adverse event that: 
• Results in death 
• Is life threatening (i.e., immediate risk of death as the event occurred). A life-threatening 
event does not include an event that, had it occurred in a more severe form, might have 
caused death, but as it occurred did not create an immediate risk of death. For example, 
hepatitis that is resolved without evidence of hepatic failure would not be considered life 
threatening even though hepatitis of a more severe nature can be fatal. Similarly, an allergic 
reaction resulting in angioedema of the face would not be life threatening, even though 
angioedema of the larynx, allergic bronchospasm, or anaphylaxis can be fatal. 
• Results in persistent or significant disability or incapacity (i.e., a substantial, persistent 
disruption in a subject’s ability to conduct normal life functions). 
• Requires inpatient hospitalization or prolongation of an existing hospitalization. 
Hospitalization or prolongation of a hospitalization constitutes criteria for an adverse event 
to be serious; however, it is not in itself considered a serious adverse event. In the absence 
of an adverse event, a hospitalization or prolongation of a hospitalization should not be 
reported as a serious adverse event by the participating Investigator. This is the case in the 
following situations:  
• The hospitalization or prolongation of hospitalization is needed for a procedure required 
by the protocol.  
• The hospitalization or prolongation of hospitalization is part of a routine procedure 
followed by the center. This should be recorded in the study file.  
In addition, a hospitalization for a pre-existing condition that has not worsened does not 
constitute a serious adverse event.  
• Results in cancer: This criterion can be excluded as it's not technically part of the definition 
of serious adverse events.  
• Results in a congenital anomaly or birth defect.  
 
Additionally, important medical events that may not result in death, be life-threatening, or require 
hospitalization may be considered a serious adverse event when, based upon appropriate medical 
judgment, the event(s) may jeopardize the subject and may require medical or surgical intervention 
to prevent one of the outcomes listed in this definition. Examples of such medical events include 
allergic bronchospasm requiring intensive treatment in an emergency room or at home, blood 
dyscrasias or convulsions that do not result in hospitalization, or the development of drug 
dependency or drug abuse. If there is any doubt whether the adverse event constitutes a serious 
adverse event, the information will be treated as a serious adverse event.  
 
 
XIII. SUBJECT COMPLETION AND WITHDRAWAL 

 
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Subject Completion 
Only subjects who complete all procedures and comply with all areas of the protocol will be deemed 
to have completed the study. If a subject voluntarily withdraws from the study, or if withdrawn by 
the Investigator for any reason, he/she will be compensated on a pro-rated basis. Subject 
compensation will be documented in the Informed Consent and will be approved by the IRB. 
If subjects agree to take part in this research study, they will be paid up to $250, 
depending on their participation. Any payments made to the subjects will be in the form of 
a debit card and issued to them in person.  
The screening visit is required to determine eligibility for the study and there is no 
compensation to the subject for completing the screening visit. 
Eligible subjects will receive the full amount of $250 at their last study visit (Visit 4).   
If subjects withdraw from the study for any reason, they will be paid only for each visit 
they have completed, not including the screening visit: $75 for completing 1 study visit, 
$150 for completing 2 study visits.  In these cases, the debit cards will be issued when the 
study team learns of subject’s withdrawal and they will be asked to come to the DCRC 
clinic to sign their payment form and pick up their debit card. 
 
Subject Withdrawal 
Subjects are free to withdraw at any time during the clinical trial. Subjects may also be withdrawn 
from the study at any time at the discretion of the Investigator. All subject withdrawals will be 
documented in the study file. Where possible, the reason for the withdrawal will be documented. 
Any withdrawals as the result of an adverse event will be followed-up at the discretion of the 
Study Investigator. Withdrawn subjects will not be replaced.  
Subject Discontinuation  
A subject will be considered discontinued from the study at any time under the following 
circumstances:  
• Any subject who violates any condition of the entrance criteria after having been entered into 
the study. 
• Any subject who develops a confounding concomitant illness (as determined by the subject, 
Research Coordinator, or Investigator) or a serious adverse event. 
• Any subject who becomes uncooperative, does not adhere to the requirements of the study 
protocol, or refuses to complete the study. 
 
XIV. EFFICACY 
 
The primary outcome variables to be assessed are: 
 
1) Gingival Abrasion Score (Van der Weijden et al. J Clin Periodontol. 2004)6) 
 

 
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After the gums are dried with compressed air, Mira-2-Ton® disclosing solution will be applied for 
better visualization of areas where the surface of the oral epithelium had been abraded. The gingival 
tissues will be divided into three areas: marginal (cervical free gingiva), interdental (papillary free 
gingiva) and mid-gingival (attached gingiva). 
 
 
The gingival abrasion scores will be measured at every visit, both before and after on-site 
brushing to assess the one-time brushing effects. In addition, the gingival abrasion scores on week 
0, week 2, and week 4 will provide insights into the cumulative effects of brushing over 2 and 4 
weeks.  
 
Gingival abrasion scores will be categorized based on abrasion size into the following groups: 
small (≤2 mm), medium (3–5 mm), and large (>5 mm). Measuring between 2 and 3 mm will be 
assigned a score of small or medium according to nearest mm mark on the probe. 
 
To avoid double-counting gingival abrasion areas, scores will be recorded by interdental site 
rather than by tooth. Each interdental site will be assessed only once and treated as a unique unit. 
Interdental areas will be scored independently from marginal and mid-gingival regions, with each 
interproximal space counted as a distinct site. 
 
Calculate and compare the mean and standard deviation (Mean +/- SD) of the gingival abrasion 
scores for each abrasion size category at each time point (before brushing, after brushing, week 0, 
week 2, and week 4). Express the frequency of different abrasion sizes at each time point to 
showcase changes over time. Interpret the findings in the context of this study, discussing both 
immediate and cumulative effects of brushing on gingival abrasion scores across different 
abrasion size categories. 
 
 
2) Bleeding on Probing (BOP) Index (Lang et al. J Clin Dent. 1986)7) 
 
Recorded from the gingival sulci of all teeth after periodontal probing at all six locations per tooth 
- mesial-buccal, buccal, distal-buccal, mesial-lingual, lingual, distal-lingual. The presence of any 
bleeding within 30 seconds of gentle probing will be considered a positive response and given a 
score of 1.  
0 = No bleeding  
1 = Bleeding 
 
The BOP index will be measured at every visit both before and after on-site brushing to assess the 

 
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one-time brushing effects. In addition, the BOP index on week 0, week 2, and week 4 will 
provide insights into the cumulative effects of brushing over 2 and 4 weeks.  
 
BOP index results will be expressed as the frequency of bleeding (1) at each time point to 
showcase changes over time. Compare the frequency of bleeding before and after brushing, as 
well as across different time points (week 0, week 2, week 4). Interpret the findings in the context 
of this study, discussing both immediate and cumulative effects of brushing on BOP index.  
 
 
3) Rustogi Modified Navy Plaque Index (PI) (Rustogi et al. J Clin Dent. 1992)5) 
 
After disclosing dental plaque on teeth with plaque disclosing solution (i.e., Mira-2-Ton), the 
Rustogi Modified Navy Plaque Index (PI) is evaluated as either present or absent (1 or 0) on each 
of the nine areas of the buccal and lingual tooth surfaces except for third molars. Whole tooth, 
marginal, and approximal areas are defined as shown below. Score of each area (from A to I) will 
be recorded for further assessments. In this study, the PI should be evaluated by only trained and 
calibrated examiners.  
 
 
 
The PI values will be measured at every visit both before and after on-site brushing to assess the 
one-time brushing effects. In addition, the PI values on week 0, week 2, and week 4 will provide 
insights into the cumulative effects of brushing over 2 and 4 weeks.  
 
PI values will be expressed as the frequency of plaque presence (1) at each time point to 
showcase changes over time. Compare the frequency of plaque presence before and after 
brushing, as well as across different time points (week 0, week 2, week 4). Interpret the findings 
in the context of this study, discussing both immediate and cumulative effects of brushing on PI 
values.  
 
4) Periodontal Probing Depth (PPD) and Clinical Attachment Loss (CAL) 
 
 
 
PPD is the distance from the free gingival margin to the base of the sulcus as measured by the 
periodontal probe.  
 

 
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CAL, the position of the attached periodontal tissues ata the base of the pocket, will be determined 
by comparing the distance from the cement-enamel Junction (CEJ) to the base of the sulcus.  
 
PPD and CAL will be determined at six sites per tooth (mesio-facial, mid facial, disto-facial, disto-
lingual, mid lingual, and mesio-lingual). PPD and CAL values will be rounded up to the next whole 
millimeter value. Full-mouth periodontal probing will be performed by one study examiner, whose 
measurements will be previously calibrated to a trained and experienced periodontist. 
 
 
 
 
 
   
XV. 
STATISTICAL ANALYSIS AND DATA MANAGEMENT   
 
 
Descriptive statistics for all subjects will be performed for background and demographic variables. 
Continuous variables are expressed as mean +/- SD and categorical variables are expressed as 
frequencies (n) and percentages (%).  
 
Student t test or Wilcoxon rank sum test where appropriate, will be used to compare among different 
bristles. For intragroup changes of endpoints before/after one-time brushing or use for 2 and 4-
weeks, paired t test or Wilcoxon signed rank test will be used where appropriate. Spearman Rank 
Order Correlation was used to analyze correlations between the variables.  
 
Safety parameters will include oral soft and hard tissues and subjective reports as well as any AEs.  
The analysis will include all observed effects which initially occurred or worsened following 
treatment. Any adverse effects will be summarized classified according to their intensity (mild, 
moderate, or severe) and relationship (definitely related, probably related, possibly related, 
probably not related, or definitely not related) to study product.  
 
All statistical tests will be conducted using Minitab 18.  
 
 
 

 
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XVI. REFERENCES 
 
1) Hoogteijling F, Hennequin-Hoenderdos NL, Van der Weijden GA, Slot DE. The effect of tapered 
toothbrush filaments compared to end-rounded filaments on dental plaque, gingivitis, and gingival 
abrasion: a systematic review and meta-analysis. Int J Dent Hyg. 2018;16(1):3–12. 
doi:10.1111/idh.12272     
2) Ni L, Tang R, He T, et al. Clinical effect of a manual toothbrush with tapered filaments on dental 
plaque and gingivitis reduction. Am J Dent. 2017;30(5):272‐278. 
3) Xu Z, Cheng X, Conde E, Zou Y, Grender J, Ccahuana-Vasquez RA. Clinical assessment of a 
manual toothbrush with CrissCross and tapered bristle technology on gingivitis and plaque 
reduction. Am J Dent. 2019;32(3):107–112. 
4) Quigley GA, Hein JW. Comparative cleansing efficiency of manual and power brushing. JADA 
1962; 65:26-29 
5) Rustogi KN, Curtis JP, Volpe AR, Kemp JH, McCool JJ, Korn LR. Refinement of the Modified 
Navy Plaque Index to increase plaque scoring efficiency in gumline and interproximal tooth areas. 
J Clin Dent. 1992;3(Suppl C):C9–C12.  
6) Van der Weijden GA, Timmerman MF, Versteeg PA, Piscaer M, Van der Velden U. High, and low 
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