Plain English Summary
Background and study aims
The aim of this trial is to identify if our experimental toothpaste promotes a reduction in tooth sensitivity and plaque compared to a marketed benchmark toothpaste.
Who can participate?
Healthy volunteers aged 18 to 65 years with a minimum of 20 natural teeth and two sensitive teeth as determined by the study investigators
What does the study involve?
Participants will be recruited and attend a screening appointment to determine if they are suitable for participation in the study. All suitable participants will then enter an acclimatization period. During this time, they will be required to brush their teeth twice per day (morning and night) using toothpaste and toothbrush supplied by the study site. The acclimatization period will be for a minimum of one day and a maximum of two weeks between screening and the start of the use of the study toothpaste, the baseline appointment.
At the baseline appointment, participants will receive a tooth examination to confirming they are suitable to continue in the study. If they are suitable, participants will have the sensitivity of their teeth tested using pressure and cold air and the amount of plaque on their teeth will be assessed. Participants will also complete a quality of life questionnaire. Participants will then be allocated to receive either an experimental toothpaste or a standard commercially available toothpaste. For both toothpastes, participants will be instructed to apply a full brush head of toothpaste to a dry toothbrush and brush their teeth twice daily, morning and night, for two mins each time over two weeks. In the baseline visit, the participants will each use their assigned toothpaste under the supervision of the investigators and the tooth sensitivity assessments will be repeated 60 seconds after application.
Participants will then complete two follow-up appointments at four days and then two weeks. At both appointments, participants will complete a quality of life questionnaire and have their teeth examination and plaque and tooth sensitivity measured.
What are the possible benefits and risks of participating?
There are no direct benefits for the participants taking part in the study, but they may help the dental profession further their knowledge in the control of dental plaque and tooth sensitivity.
The risks for the participants taking part in the study are minimal. Participants may experience tooth discomfort during the sensitivity assessments. The assessments for tooth sensitivity require applying stimuli (touch and cold air) to their teeth which may cause a short sharp pain. The stimuli are of a short duration and are no different than the discomfort that may be experienced by the participants in everyday life, for example, by brushing their teeth with cold water, or having a cold drink.
Where is the study run from?
Clinical Trials Unit, Bristol Dental School and Hospital (UK)
When is the study starting and how long is it expected to run for?
September 2019 to October 2020 (updated 19/08/2020, previously: December 2020)
Who is funding the study?
Sunstar Suisse (Switzerland)
Who is the main contact?
Prof. Nicola West
2019-7760, IRAS 266661
A clinical study investigating the benefits of a hydroxyapatite/potassium nitrite and aluminium lactate cosmetic toothpaste to help the discomfort associated with dentine hypersensitivity compared to a benchmark marketed toothpaste
An experimental hydroxylapatite/potassium nitrite and aluminium lactate toothpaste will have an increased effect to promote a healthy mouth with regards to the reduction of sensitive teeth from dentine hypersensitivity and reduction of plaque compared to a marketed benchmark toothpaste.
Pending as of 24/02/2020, South West - Frenchay Research Ethics Committee (Level 3, Block B, Whitefriars, Lewins Mead, Bristol, BS1 2NT; firstname.lastname@example.org; +44 0207 104 8029), ref: 20/SW/0036
Single-centre, investigator-blinded, two-arm, baseline-controlled randomized parallel trial
Primary study design
Secondary study design
Randomised parallel trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Oral health and tooth sensitivity
Participants will be recruited and attend a screening appointment to determine eligibility. All eligible participants will be provided with the toothbrush, toothpaste and timing instructions for the acclimatization period. All participants will use an acclimatization product which is Signal Toothpaste (Unilever). Participants will apply a strip of this toothpaste to cover the head of the toothbrush provided and brush their teeth for one timed minute twice daily (morning and evening) for a minimum of one day and a maximum of two weeks between screening and baseline.
At the baseline appointment, participants will receive an Oral Soft Tissue (OST) examination to confirming the participant's continuing eligibility for the study. Confirmed eligible participants will have two sensitive teeth selected for treatment and undergo baseline tooth sensitivity (Schiff sensitivity scale score elicited by an evaporative (air) stimulus, tactile sensitivity score elicited by a Yeaple probe stimulus and dentin hypersensitivity) and plaque score assessments. Participants will also complete a baseline quality of life questionnaire. Participants will then be randomized to receive either experimental toothpaste or benchmark controlled toothpaste according to a table prepared by the study Statistician.
The experimental toothpaste is hydroxylapatite /potassium nitrite and aluminium lactate (calcium aluminium phosphate precipitate) and the benchmark control toothpaste is Sensodyne Daily Care. For both toothpastes, participants will be instructed to apply a full brush head of toothpaste to a dry toothbrush and brush their teeth twice daily, morning and night, for two mins over two weeks.
In the baseline visit, the participants will each use their assigned toothpaste under supervision and tooth sensitivity assessments will be repeated 60 s after application.
Participants will then complete two follow-up appointments at four days and two weeks respectively. At both appointments, participants will complete a quality of life questionnaire and undergo OST examination and plaque and sensitivity assessments.
Primary outcome measure
Tooth sensitivity assessed by Schiff sensitivity scale score elicited by an evaporative (air) stimulus at baseline and 4 days
Secondary outcome measures
1. Tooth tactile sensitivity assessed by tactile sensitivity score elicited by a Yeaple probe stimulus at baseline and 4 days.
2. Tooth sensitivity after immediate use assessed by Schiff sensitivity scale score elicited by an evaporative (air) stimulus and tactile sensitivity score elicited by a Yeaple probe stimulus at baseline and 60 s.
3. Long term tooth sensitivity assessed by Schiff sensitivity scale score elicited by an evaporative (air) stimulus and tactile sensitivity score elicited by a Yeaple probe stimulus at baseline and 2 weeks.
4. Dentin hypersensitivity relief assessed by visual analogue scale (VAS) at baseline, 60 s, 4 days and 2 weeks
5. Plaque assessed by quantitative light-induced fluorescence-digital (QLF-D) at baseline, 4 days and 2 weeks
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Voluntary written informed consent given
2. Aged 18 to 65 years
3. Good general and mental health in the opinion of the investigator or medically qualified designee
a. No clinically significant and relevant abnormalities of medical history or oral examination
b. No condition that would impact on safety, wellbeing or ability to understand and follow study procedures and requirements
4. Understands and is willing, able and likely to comply with all study procedures and restrictions
5. Minimum of 20 natural teeth
6. 2 sensitive teeth as defined by Schiff scores 2/3 to evaporative stimuli
7. Minimum of two, non-adjacent accessible teeth (incisors, canines, pre-molars), that have signs of sensitivity, measured by qualifying tactile stimulus (Yeaple ≤ 20g) and evaporative air assessment (Schiff sensitivity score ≥ 2)
Target number of participants
Approximately 150 will be screened to ensure approximately 90 subjects will be randomized to ensure 80 subjects complete the study (approximately 40 per treatment group). Approximately equal number of male and female gender will be recruited to the study in each group scoring 2 or 3 on a Schiff test to a cold air blast.
Participant exclusion criteria
1. Known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients
2. Participation in another clinical study (including cosmetic studies) or receipt of an investigational drug within 15 days of the screening visit
3. Previous participation in this study
4. Recent history (within the last year) of alcohol or other substance abuse
5. An employee of the sponsor or members of their immediate family
6. An employee of the site for this protocol (the Bristol Dental School and Hospital) and associated with the Clinical Trials unit
6. Presence of chronic debilitating disease which, in the opinion of the investigator, could affect study outcomes.
7. Any condition which, in the opinion of the investigator, causes xerostomia
8. Dental prophylaxis within 4 weeks of screening
9. Tongue or lip piercing
10. Desensitizing treatment within 2 weeks of screening (professional sensitivity treatments and non-dentifrice sensitivity treatments)
11. Active periodontal disease
12. Teeth bleaching within 8 weeks of screening
13. Teeth with exposed dentine but used as abutments for fixed or removable partial dentures, teeth with full crowns or veneers, orthodontic bands or cracked enamel
14. Teeth with evidence of caries
15. Daily prescription of medication/treatments which, in the opinion of the investigator, could interfere with the perception of pain. Including but not limited to: analgesics, anticonvulsants, antihistamines that cause marked or moderate sedation, sedatives, tranquilizers, anti-depressants, and mood-altering and anti-inflammatory drugs.
16. Any subject who, in the judgment of the investigator, should not participate in the study
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Bristol Dental Clinical Trials Unit
Bristol Dental School and Hospital University of Bristol Lower Maudlin Street
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Through peer-reviewed journal publication and presentation of results at an international dental conference. No additional documents are available.
IPD sharing statement
The data sharing plans for the current study are unknown and will be made available at a later date.
Intention to publish date
Participant level data
To be made available at a later date
Basic results (scientific)