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

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.


Eligibility Criteria:
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