A Study to Assess Efficacy of an Experimental Oral Rinse in Providing Long Term Relief From Dentinal Hypersensitivity

Study Overview
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Brief Summary
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To investigate the efficacy of an experimental oral rinse, containing 1.5% potassium oxalate (KOX) and 0 parts per million (ppm) fluoride in relieving dentine hypersensitivity (DH) after 8 weeks use compared with a placebo oral rinse and a commercialized fluoride oral rinse.

Detailed Description
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This will be a single centre, eight week, randomized, examiner-blind, three treatment, parallel group, stratified study. It will be conducted in healthy participants, with at least two sensitive teeth that meet all of the study criteria at the Screening and Baseline visits. DH will be assessed at Baseline, and after 4 and 8 weeks twice daily treatment.

Official Title
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A Method Development Clinical Study Investigating the Efficacy of an Experimental Oral Rinse in Providing Long Term Relief From Dentinal Hypersensitivity

Conditions
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Dentin Sensitivity

Intervention / Treatment
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* Device: Potassium oxalate
* Drug: Sodium fluoride
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Demonstrates understanding of the study procedures, restrictions and willingness to participate as evidenced by voluntary written informed consent and has received a signed and dated copy of the informed consent form. Good general and mental health with, in the opinion of the investigator or medically qualified designee: a) No clinically significant and relevant abnormalities in medical history or oral Examination and b) Absence of any condition that would impact on the participant's safety or wellbeing or affect the individual's ability to understand and follow study procedures and requirements. Dental Health at Screening: a) Self-reported history of DH lasting more than six months but not more than 10 Years, b) Minimum of 20 natural teeth, c) Minimum of 4 accessible non-adjacent teeth (incisors, canines, premolars), preferably in different quadrants, that meet all of the following criteria: Signs of facial/cervical gingival recession and/or signs of erosion or abrasion (EAR), Tooth with MGI score =0 adjacent to the test area (exposed dentine) only and a clinical mobility of ≤1 and tooth with signs of sensitivity measured by qualifying evaporative air assessment (Schiff sensitivity score ≥ 2). Dental Health at Baseline: Minimum of two, non-adjacent accessible teeth (incisors, canines, premolars), that meet all of the following criteria: Tooth with signs of sensitivity, measured by qualifying tactile stimulus (Yeaple ≤20g) and evaporative air assessment (Schiff sensitivity score ≥ 2. Females of childbearing potential who are, in the opinion of the investigator, practicing a reliable method of contraception. Adequate contraception is defined as abstinence, oral contraceptive, either combined or progestogen alone or injectable progestogen or implants of levonorgestrel or estrogenic vaginal ring or percutaneous contraceptive patches or intrauterine device or intrauterine system or double barrier method (condom or occlusive cap [diaphragm or cervical vault caps] plus spermicidal agent [foam, gel, film, cream, suppository]) or male partner sterilization prior to the female participant's entry into the study, and this male is the sole partner for that participant). Participant will be current and regular (twice daily), users of an over the counter (OTC) Monograph or cosmetic oral rinse. Participant will be cell phone owners so that they can contactable by SMS. Exclusion Criteria: A woman who is known to be pregnant or who is intending to become pregnant over the duration of the study. A woman who is breast-feeding. Known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients. Participation in another clinical study (including cosmetic studies) or receipt of an investigational drug within 30 days of the screening visit or previous participation in this study. Recent history (within the last year) of alcohol or other substance abuse. An employee of the sponsor or the study site or members of their immediate family. Presence of chronic debilitating disease which, in the opinion of the investigator, could affect study outcomes. Any condition which, in the opinion of the investigator, causes xerostomia. Dental prophylaxis within 4 weeks of Screening. Tongue or lip piercing. Desensitizing treatment within 8 weeks of Screening (professional sensitivity, treatments and non-dentifrice sensitivity treatments). Gross periodontal disease, treatment of periodontal disease (including surgery) within 12 months of Screening, scaling or root planning within 3 months of Screening. Teeth bleaching and any teeth whitening procedures within 8 weeks of Screening. Tooth with evidence of current or recent caries, or reported treatment of decay within 12 months of Screening. Tooth with exposed dentine but with deep, defective or facial restorations, teeth used as abutments for fixed or removable partial dentures, dental implants, teeth with full crowns or veneers, orthodontic bands or cracked enamel. Sensitive teeth with contributing aetiologies other than erosion, abrasion or recession of exposed dentine. Sensitive tooth not expected to respond to treatment with an over-the-counter dentifrice in the opinion of the investigator. Use of an oral care product indicated for the relief of dentine hypersensitivity within 8 weeks of screening (Participants will be required to bring their current oral care products to the site in order to verify the absence of known anti-sensitivity ingredients). Daily doses of medication/treatments which, in the opinion of the investigator, could interfere with the perception of pain. Examples of such medications include analgesics, anticonvulsants, antihistamines that cause marked or moderate sedation, sedatives, tranquilisers, anti-depressants, mood-altering and anti-inflammatory drugs. Currently taking antibiotics or has taken antibiotics within two weeks of Baseline. Daily dose of a medication which, in the opinion of the investigator, is causing xerostomia. Presence of kidney disease, hyperoxaluria, or any other condition that may be exacerbated by oxalic acid or oxalate salts. Presence of chronic debilitating disease which, in the opinion of the investigator, could affect study outcomes. Any participant who, in the judgment of the investigator, should not participate in the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Test Product<br>Participants will rinse twice daily (morning and evening) with 10 milliliters (mL) of oral rinse for 60 timed seconds and expectorate. No further rinsing with water will be permitted after use of the oral rinse. | Device: Potassium oxalate<br>* Oral rinse containing 1.5 percent (%) KOX and 0 ppm fluoride<br>|
| Other: Negative Control<br>Participants will rinse twice daily (morning and evening) with 10 mL of oral rinse for 60 timed seconds and expectorate. No further rinsing with water will be permitted after use of the oral rinse. | Drug: Sodium fluoride<br>* Oral rinse containing 0.02% weight by weight (w/w) sodium fluoride (NaF)<br>|
| Placebo Comparator: Placebo<br>Participants will rinse twice daily (morning and evening) with 10 mL of oral rinse for 60 timed seconds and expectorate. No further rinsing with water will be permitted after use of the oral rinse. | Other: Placebo<br>* Oral rinse containing 0% KOX and 0 ppm fluoride<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Schiff Sensitivity Score | The examiner assessed the participant's response to an evaporative air stimulus for each tooth using the Schiff Sensitivity Scale which was scored as follows - 0: Participant did not respond to air stimulation; 1: Participant responded to air stimulus but does not request discontinuation of stimulus; 2: Participant responded to air stimulus and requested discontinuation or moves from stimulus; 3: Participant responded to stimulus, considered stimulus to be painful, and requested discontinuation of the stimulus. A reduction in Schiff Sensitivity score will be indicative of an improvement in sensitivity. | Week 8 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Tactile Threshold | The examiner assessed the response to tactile sensitivity using a Yeaple probe which allowed the application of a known force to the dentin surface, starting at 10 grams (g) and rising in increments of 10g until the tactile threshold or maximum force was reached. The tactile threshold for each tooth was determined by asking the participant whether the sensation caused discomfort. The pressure setting at which the participant gave two consecutive 'yes' responses was recorded as the tactile threshold. The higher the tactile threshold, the less sensitive the tooth. At baseline, the maximum force used was 20g; at all subsequent visits, it was 80g. | Week 8 |