Dose Response of a Tubule Occlusion Agent

To evaluate the efficacy of two different concentrations of a tubule occlusion agent - calcium sodium phosphosilicate in treatment of dentine hypersensitivity

Dentine hypersensitivity is characterized by short, sharp pain arising from exposed dentine typically in response to chemical, thermal, tactile or osmotic stimuli. Dentine hypersensitivity may be treated by either making the nerve in the tooth less sensitive or by occluding the tubules to limit exposure of the nerve to external stimuli. Bioactive and biocompatible glasses react with oral fluid to deposit a mineral that is chemically analogous to that found in both enamel and dentine thus preventing exposure of the nerve to external stimuli.

A number of controlled clinical trials have been reported indicating that a calcium sodium phosphosilicate bioactive glass, when incorporated into a toothpaste formulation, significantly reduce pain from dentine hypersensitivity. The aim of this study is to evaluate the effectiveness of two currently marketed toothpastes, containing 5% calcium sodium phosphosilicate and the other containing 7.5% calcium sodium phosphosilicate in the treatment of dentine hypersensitivity compared to a matched placebo control.

Eligibility Criteria:
Inclusion Criteria:

1. Consent: Demonstrates understanding of the study and willingness to participate as evidenced by voluntary written informed consent and has received a signed and dated copy of the informed consent form.
2. Age: Aged between 20 - 50 years.
3. General Health: Good general health with (in the opinion of the investigator) no clinically significant and relevant abnormalities of medical history.
4. Contraception: Females of childbearing potential who are, in the opinion of the investigator, practising a reliable method of contraception.
5. Erosion/Abrasion/Recession:Study teeth must show signs of facial/cervical erosion, abrasion and/or gingival recession.
6. Gingival Health / Tooth Mobility Grade:Study teeth must have Löe and Silness Gingival Index (GI) score less than or equal to 2 and clinical mobility less than or equal to grade I.
7. Current Product Use: Participants must have been using the same brand of toothpaste for at least 2 months and should not have used desensitizing toothpaste during the 4 weeks preceding screening. Participants will be required to bring in their current toothpaste(s) in order to verify the ingredients.
8. VAS Training: Successfully completes the VAS training exercise at Screening.
9. Sensitivity: Self-reported history of dentinal hypersensitivity and a primary complaint of sensitive teeth lasting a maximum of 10 years. At Screening: A minimum of 5 evaporative (air) sensitive lateral incisors, canines or pre-molars must display a response greater than 25 mm on a 100 mm VAS. At Baseline: A minimum of 3 of the 5 evaporative (air) sensitive teeth identified at screening must display a response greater than 25 mm on a 100 mm VAS. All teeth meeting the sensitivity Inclusion Criteria will be followed and assessed using both efficacy parameters.
10. Compliance: Understands and is willing, able and likely to comply with all study procedures and restrictions.

Exclusion Criteria:

1. Pregnancy: Women who are known to be pregnant or who are intending to become pregnant over the duration of the study.
2. Breast-feeding: Women who are breast-feeding.
3. Medical History: a) Chronic debilitating disease is present b)Chronic disease or other condition is present that is associated with intermittent episodes or constant daily pain, such as arthritis, low back pain, dysmenorrhea, etc.
4. Medications: Daily doses of medication, which in the opinion of the investigator, might interfere with the perception of pain, are being taken. Examples of such medications include analgesics, anticonvulsants, antihistamines that cause marked or moderate sedation, sedatives, tranquilizers, mood-altering and anti-inflammatory drugs.
5. Dentition Exclusions: a) Sensitive teeth not expected to respond to treatment with an over-the- counter (OTC) dentifrice in the opinion of the investigator. b) Teeth with exposed dentine but with deep, defective or facial restorations, teeth used as abutments for fixed or removable partial dentures, teeth with full crowns, orthodontic bands, extensive caries or cracked enamel. Sensitive teeth with contributing aetiologies other than erosion, abrasion or recession of exposed dentine. c) Dental professional hygiene (includes dental prophylaxis, irrigation, and intensive anti-microbial/anti-biotic therapy) within 14 days of the screening visit. d) Presence of dental implants. e) Lip or tongue piercings. f) Periodontal surgical history within the past 6 months or have been scaled /root planed within the past 3 months.
6. Allergy/Intolerance: Known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients.
7. Clinical Study/Experimental Medication: a) Participation in another clinical study or receipt of an investigational drug within 30 days of the screening visit.b) Previous participation in this study.
8. Xerostomia: Any condition or medication that causes xerostomia.
9. Personnel: An employee of the sponsor or the study site or members of their immediate family.
10. Other: Any subject who in the opinion of the investigator, should not participate in the study.