Effect of Fluoride in a Dentifrice on Remineralization of Erosive Lesions

Study Overview
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Brief Summary
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The proposed study will evaluate the performance of fluoride delivered from a new dentifrice formulation without potassium nitrate. It will also evaluate the dose-response to fluoride by testing four dentifrices covering a range of sodium fluoride concentration.

Official Title
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The Effect of Fluoride in an Experimental Dentifrice on Remineralization of Erosive Lesions In-Situ

Conditions
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Enamel Erosion

Intervention / Treatment
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* Drug: sodium fluoride
* Drug: no added fluoride in a silica base


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: intact maxillary dental arch suitable to retain a palatal appliance, an intact mandibular dental arch and a stimulated/unstimulated saliva flow rate of ≥ 0.8 milliliter/minute (ml/min) and ≥ 0.2 ml/min respectively.

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: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low ppm fluoride dentifrice<br>Low ppm fluoride as sodium fluoride in a silica base dentifrice | Drug: sodium fluoride<br>* fluoride as sodium fluoride<br>|
| Experimental: Medium ppm fluoride dentifrice<br>Medium ppm fluoride as sodium fluoride in a silica base dentifrice | Drug: sodium fluoride<br>* fluoride as sodium fluoride<br>|
| Experimental: High ppm fluoride dentifrice<br>High ppm fluoride as sodium fluoride in a silica base dentifrice | Drug: sodium fluoride<br>* fluoride as sodium fluoride<br>|
| Placebo Comparator: No fluoride dentifrice<br>no added fluoride in a silica base dentifrice | Drug: no added fluoride in a silica base<br>* no added fluoride<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage Surface Microhardness Recovery (%SMHR) Dose Response Relationship | SMHR test was used to assess the changes in mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMHR 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 SMHR 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. | Baseline to 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| %SMHR | SMHR test was used to assess the changes in mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMHR 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 SMHR 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. | Baseline to 4 hours | 
| Percentage Relative Erosion Resistance | Changes in mineral content of enamel specimens exposed to dietary erosive challenge were determined by measuring the length of the indentations. Decrease in the indentation length compared to the baseline indicates hardening of enamel surface. Enamel specimens were exposed to second erosion challenge to determine relative erosion resistance which compared the indentations values of enamel specimens at baseline (B), first erosive (E1) and second erosive challenge (E2). Percent relative erosion resistance was calculated by formula: [(E1-E2)/ (E1-B)]*100. | Baseline to 4 hours | 
| Enamel Fluoride Uptake (Corrected Data) | Enamel fluoride uptake was determined using the microdrill enamel biopsy technique. The amount of fluoride uptake by enamel was calculated based on amount of fluoride divided by area of the enamel cores. Data analysis was based on corrected data. | Baseline to 4 hours |