Evaluation of Efficacy of Experimental Gel to Foam Dentifrices in Dental Erosion

Study Overview
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Brief Summary
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The purpose of this study is to compare and evaluate the ability of two European Union (EU) regulated gel to foam toothpaste formulations versus a non-fluoride toothpaste using a modified in-situ model of dental erosion and remineralization. A positive control i.e fluoride containing toothpaste marketed in EU will also be compared to non-fluoride toothpaste.

Detailed Description
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The aim of this study is to assess the remineralization effects of two EU gel to foam toothpaste formulations with 1450 parts per million (ppm) of fluoride as sodium fluoride (NaF) and 5% potassium nitrate (KNO3) versus a non-fluoride (0 ppm F)/KNO3 toothpaste as a negative control. The two experimental gel to foam toothpaste formulations differ in their relative dentine abrasivity (RDA) values which is an in-vitro measure of a toothpaste abrasivity to the dentinal tissues. A marketed toothpaste containing NaF and KNO3 will serve as a positive control.

Official Title
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A Placebo Controlled Study to Evaluate the Effectiveness of Experimental Foaming Gel Toothpastes Using an In-situ Erosion Remineralization Model

Conditions
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Dental Erosion, Acid Wear

Intervention / Treatment
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* Drug: Sodium Fluoride
* Drug: Potassium nitrate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: General and Oral Health: Good general health with (in the opinion of the investigator) no clinically OST and OHT examinations. Oral Requirements: An intact maxillary dental arch suitable for the retention of the palatal appliance and an intact mandibular dental arch. Subjects may have fixed bridges replacing missing teeth. A gum base stimulated whole saliva flow rate ≥ 0.8 g/min and an unstimulated whole saliva flow rate ≥ 0.2 g/min. Contraception: Women of childbearing potential who are, in the opinion of the investigator, practicing a reliable method of contraception. Exclusion Criteria: Oral Health: Current active caries or periodontal disease that may compromise the study or the health of the subjects. Lesions of the oral cavity that could interfere with the study evaluations, including severe gingivitis, grossly carious lesions, periodontitis and other severe periodontal disease. Allergy/Intolerance: Known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients. Clinical Study/Experimental Medication: Participation in another clinical study or receipt of an investigational drug within 30 days of the screening visit Previous participation in this study Substance abuse: Recent history (within the last year) of alcohol or other substance abuse. Pregnancy: Women who are pregnant or who are intending to become pregnant over the duration of the study Breast-feeding: Women who are breast-feeding

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: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: NaF/KNO3 toothpaste, Low RDA<br>Participants to brush with 1.5 g of low RDA gel to foam toothpaste containing 1450 ppm F - EU level as NaF. All study treatments contain 5% weight by weight (w/w) KNO3. | Drug: Sodium Fluoride<br>* Toothpaste containing 1450 ppm F - EU level as NaF.<br>Drug: Potassium nitrate<br>* All study treatments contain 5% w/w KNO3.<br>|
| Experimental: NaF/KNO3 toothpaste, Medium RDA<br>Participants to brush with 1.5 g of medium RDA gel to foam toothpaste containing 1450 ppm F - EU level as NaF. All study treatments contain 5% w/w KNO3. | Drug: Sodium Fluoride<br>* Toothpaste containing 1450 ppm F - EU level as NaF.<br>Drug: Potassium nitrate<br>* All study treatments contain 5% w/w KNO3.<br>|
| Active Comparator: NaF/KNO3 toothpaste<br>Participants to brush with 1.5 g of NaF/KNO3 toothpaste containing 1450 ppm F - EU level as NaF. All study treatments contain 5% w/w KNO3. | Drug: Sodium Fluoride<br>* Toothpaste containing 1450 ppm F - EU level as NaF.<br>Drug: Potassium nitrate<br>* All study treatments contain 5% w/w KNO3.<br>|
| Placebo Comparator: No fluoride/KNO3 toothpaste<br>Participants to brush with a fluoride free toothpaste (0 ppmF). All study treatments contain 5% w/w KNO3. | Drug: Potassium nitrate<br>* All study treatments contain 5% w/w KNO3.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relative Erosion Resistance (RER) of Enamel Specimens Post 4 Hours of Treatment Exposure | Enamel specimens were exposed to dietary erosive challenge and set of five indentations within each specimen was measured. Decrease in the indentation length compared to the baseline indicates hardening of enamel surface. Enamel specimens were exposed to second erosion challenge to determine RER which compared the indentations values of enamel specimens at baseline (B), first erosive (E1) and second erosive challenge (E2). Percent RER was calculated by formula: [(E1-E2)/ (E1-B)]*100. Smaller the negative RER, better is treatment regimen in imparting resistance to enamel. | Baseline, 4 hours post treatment in each treatment period | 
| Surface Microhardness (SMH) Recovery of Enamel Specimens Post 4 Hours of Treatment Exposure | SMH test was used to assess mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMH was determined by measuring the length of the indentations of enamel specimens. An increase in the indentation length compared to the baseline indicates softening while decrease in the indentation length represents rehardening of enamel surface. Percent SMH recovery was calculated from indentation values of enamel specimens at baseline (B), after in-situ hardening (R) and after first erosive challenge (E1) using formula: [(E1- R)/ (E1-B)]*100. A higher percentage values indicate a better outcome. | Baseline, 4 hours post treatment in each treatment period |