Efficacy of Two Experimental Oral Rinses in Providing Long Term Relief From Dentinal Hypersensitivity

Study Overview
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Brief Summary
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This study will investigate the longitudinal efficacy of two experimental oral rinses containing 1.5% weight/weight (w/w) dipotassium oxalate monohydride (KOX), formulated at pH 4.5 and pH 7 respectively, for the relief of dentinal hypersensitivity (DH), compared to a placebo oral rinse, when used as an adjunct to twice daily brushing with a standard fluoride toothpaste.

Official Title
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A Clinical Study Investigating the Efficacy of Two Experimental Oral Rinses in Providing Long Term Relief From Dentinal Hypersensitivity

Conditions
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Dentin Sensitivity

Intervention / Treatment
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* Device: Experimental Oral Rinse 1
* Device: Experimental Oral Rinse 2
* Other: Placebo Oral Rinse
* Drug: Standard fluoride toothpaste


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 Aged between 18 and 55 years inclusive 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 upon oral examination. B. Absence of any condition that would impact on the subject'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 dentinal hypersensitivity (DH) lasting more than six months but not more than 10 years. B. Good general oral health, with a minimum of 20 natural teeth. C. Minimum of 2 accessible non-adjacent teeth (incisors, canines, pre-molars), 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 modified gingival index (MGI) score =0 adjacent to the test area (exposed dentine) only and a clinical mobility of ≤1. Tooth with signs of sensitivity measured by qualifying evaporative air assessment (Y/N response). At Baseline: D. Minimum of two, non-adjacent accessible teeth (incisors, canines, pre-molars), 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) Exclusion Criteria: Pregnant or breast feeding women Daily doses of medication/treatments which, in the opinion of the investigator, could interfere with the perception of pain. 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 condition which, in the opinion of the investigator, causes xerostomia. Treatment of periodontal disease within 12 months of screening 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. Recent history (within the last year) of alcohol or other substance abuse Dental prophylaxis within four weeks of Screening. Tongue or lip piercing or presence of dental implants. Desensitizing treatment within eight weeks of Screening (professional sensitivity treatments and non-toothpaste 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 within eight 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, 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 toothpaste in the opinion of the investigator. Use of an oral care product indicated for the relief of dentine hypersensitivity within eight weeks of screening Individuals who require antibiotic prophylaxis for dental procedures

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental Oral Rinse1<br>Brushing with fluoride toothpaste for 1 minute followed by rinsing with 10 ml of Experimental Oral Rinse 1 for 1 minute. This regimen will be performed twice daily for 8 weeks. | Device: Experimental Oral Rinse 1<br>* (1.5% w/w KOX, pH 4.5)<br>Drug: Standard fluoride toothpaste<br>* 1000ppm fluoride as sodium monofluorophosphate<br>|
| Experimental: Experimental Oral Rinse 2<br>Brushing with fluoride toothpaste for 1 minute followed by rinsing with 10 ml of Experimental Oral Rinse 2 for 1 minute. This regimen will be performed twice daily for 8 weeks. | Device: Experimental Oral Rinse 2<br>* (1.5% w/w KOX, pH 7)<br>Drug: Standard fluoride toothpaste<br>* 1000ppm fluoride as sodium monofluorophosphate<br>|
| Placebo Comparator: Placebo Oral Rinse<br>Brushing with fluoride toothpaste for 1 minute followed by rinsing with 10 ml of Placebo Oral Rinse 2 for 1 minute. This regimen will be performed twice daily for 8 weeks. | Other: Placebo Oral Rinse<br>* (0% w/w KOX, pH 4.5)<br>Drug: Standard fluoride toothpaste<br>* 1000ppm fluoride as sodium monofluorophosphate<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 of Experimental Oral Rinses 1 and 2 Against a Placebo Oral Rinse at Week 8 | The examiner assessed the participant's response to an evaporative air stimulus for each tooth using the Schiff Sensitivity Scale scored as follows - 0: Participant does not respond to air stimulation; 1: responds to air stimulus but does not request discontinuation of stimulus; 2: Participant responds to air stimulus and requests discontinuation or moves from stimulus; 3: Participant responds to stimulus, considers stimulus to be painful, and requests discontinuation of the stimulus. A reduction in Schiff Sensitivity score indicate improvement in sensitivity. | Baseline, Week 8 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Schiff Sensitivity Score of Two Experimental Oral Rinses 1 and 2 at Week 8 | The examiner assessed the participant's response to an evaporative air stimulus for each tooth using the Schiff Sensitivity Scale scored as follows - 0: Participant does not respond to air stimulation; 1: responds to air stimulus but does not request discontinuation of stimulus; 2: Participant responds to air stimulus and requests discontinuation or moves from stimulus; 3: Participant responds to stimulus, considers stimulus to be painful, and requests discontinuation of the stimulus. A reduction in Schiff Sensitivity score indicate improvement in sensitivity. | Baseline, Week 8 | 
| Change From Baseline in Schiff Sensitivity Score of Two Experimental Oral Rinses 1 and 2 and a Placebo Oral Rinse at Week 4 | The examiner assessed the participant's response to an evaporative air stimulus for each tooth using the Schiff Sensitivity Scale scored as follows - 0: Participant does not respond to air stimulation; 1: responds to air stimulus but does not request discontinuation of stimulus; 2: Participant responds to air stimulus and requests discontinuation or moves from stimulus; 3: Participant responds to stimulus, considers stimulus to be painful, and requests discontinuation of the stimulus. A reduction in Schiff Sensitivity score indicate improvement in sensitivity. | Baseline, Week 4 | 
| Change From Baseline in Tactile Threshold (Gram [g]) of Two Experimental Oral Rinses 1 and 2 and a Placebo Oral Rinse at Week 4 | The examiner assessed the response to tactile sensitivity using a Yeaple probe which allowed application of a known force to the dentin surface, starting at 10g and rising in increments of 10g until the tactile threshold or maximum force has 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. However, in situations where participants did not give a 'yes' response at force of 80g, the tactile threshold was recorded as >80g. For analysis purposes values recorded as >80g were treated as 90g values. | Baseline, Week 4 | 
| Change From Baseline in Tactile Threshold (g) of Two Experimental Oral Rinses 1 and 2 and a Placebo Oral Rinse at Week 8 | The examiner assessed the response to tactile sensitivity using a Yeaple probe which allowed application of a known force to the dentin surface, starting at 10g and rising in increments of 10g until the tactile threshold or maximum force has 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. However, in situations where participants did not give a 'yes' response at force of 80g, the tactile threshold was recorded as >80g. For analysis purposes values recorded as >80g were treated as 90g values. | Baseline, Week 8 | 
| Change From Baseline in Visual Rating Scale (VRS) of Two Experimental Oral Rinses 1 and 2 and a Placebo Oral Rinse) at Week 4 | Participants rated the intensity of their response to the evaporative (air) stimulus using a 10 point VRS. The Participants were asked to rate their pain on a scale of 1 (No Pain) to 10 (Intense Pain). A reduction in the score is indicative of an improvement in sensitivity. | Baseline, Week 4 | 
| Change From Baseline in VRS of Two Experimental Oral Rinses 1 and 2 and a Placebo Oral Rinse) at Week 8 | Participants rated the intensity of their response to the evaporative (air) stimulus using a 10 point VRS. The Participants were asked to rate their pain on a scale of 1 (No Pain) to 10 (Intense Pain). A reduction in the score is indicative of an improvement in sensitivity. | Baseline, Week 8 |