Effect of Dentifrice Usage Regime on Delivery and Efficacy of Fluoride

Study Overview
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Brief Summary
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This study will evaluate and compare the effect of the amount of toothpaste used and brushing time on enamel strengthening (percent of surface microhardness recovery, % SMHR) and enamel fluoride uptake (EFU).

Official Title
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A Study to Measure the Effect of Dentifrice Usage Regime on Delivery and Efficacy of Fluoride Using an In Situ Caries Model

Conditions
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Dental Caries

Intervention / Treatment
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* Drug: Sodium fluoride / silica and carbopol, 0.5g
* Drug: Sodium fluoride / silica and carbopol, 1.5g
* Drug: Sodium fluoride / silica and carbopol, 1.5g
* Other: Fluoride free dentifrice


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: General and Dental Health Good general and dental health with (in the opinion of the investigator) no clinically significant and relevant abnormalities of medical history or oral examination Have no current active caries or periodontal disease that may compromise the study or the health of the subjects Residency: Currently living in the Indianapolis, Indiana area Dentures: Currently wearing a removable mandibular partial denture with sufficient room in the posterior buccal flange area to accommodate two enamel specimens (required dimensions 12 mm x 7 mm) Willing to have their denture modified to accommodate enamel test specimens and willing and capable of wearing their removable mandibular partial dentures 24 hours per day during the experimental periods All restorations in a good state of repair Salivary Flow: Have a salivary flow rate in the range of normal values (unstimulated whole saliva flow rate ≥ 0.2 mL/minute; gum base stimulated whole saliva flow rate ≥ 0.8 mL/minute) Exclusion Criteria: Antibiotics: Use of antibiotics two weeks prior to a treatment visit or anticipated use during the study treatment periods Study Scale Use: Subjects unable to measure product weights accurately using the assigned study scale as determined by the study staff (as demonstrated on or before Visit 4) A member of the site study staff who is directly working on the project or living in that staff's household Any employee of any toothpaste manufacturer or their spouse or family member

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Experimental dentifrice 0.5g, 45 seconds brushing group<br>Participants brush twice a daily for 45 seconds with experimental dentifrice. | Drug: Sodium fluoride / silica and carbopol, 0.5g<br>* Dentifrice containing 1150 parts per million (ppm) fluoride as sodium fluoride / silica and 0.4% carbopol<br>Other: Fluoride free dentifrice<br>* A non fluoride dentifrice was given to participants of each arm at washout period<br>|
| Experimental: Experimental dentifrice 1.5g, 45 seconds brushing group<br>Participants brush twice a daily for 45 seconds with experimental dentifrice. | Drug: Sodium fluoride / silica and carbopol, 1.5g<br>* Dentifrice containing 1150 ppm fluoride as sodium fluoride / silica and 0.4% carbopol<br>Other: Fluoride free dentifrice<br>* A non fluoride dentifrice was given to participants of each arm at washout period<br>|
| Experimental: Experimental dentifrice 0.5g, 2 minutes brushing group<br>Participants brush twice a daily for 2 minutes with experimental dentifrice. | Drug: Sodium fluoride / silica and carbopol, 0.5g<br>* Dentifrice containing 1150 parts per million (ppm) fluoride as sodium fluoride / silica and 0.4% carbopol<br>Other: Fluoride free dentifrice<br>* A non fluoride dentifrice was given to participants of each arm at washout period<br>|
| Experimental: Experimental dentifrice 1.5g, 2 minutes brushing group<br>Participants brush twice a daily for 2 minutes with experimental dentifrice. | Drug: Sodium fluoride / silica and carbopol, 1.5g<br>* Dentifrice containing 1150 ppm fluoride as sodium fluoride / silica and 0.4% carbopol<br>Other: Fluoride free dentifrice<br>* A non fluoride dentifrice was given to participants of each arm at washout period<br>|
| Active Comparator: Contol group<br>Participants brush twice a daily for 2 minutes with controll dentifrice. | Drug: Sodium fluoride / silica and carbopol, 1.5g<br>* Dentifrice containing 250 ppm fluoride as sodium fluoride / silica and 0.4% carbopol<br>Other: Fluoride free dentifrice<br>* A non fluoride dentifrice was given to participants of each arm at washout period<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage Surface Micro Hardness Recovery (% SMH), of Brushing for 2 Minutes Versus (vs.) Brushing for 45 Seconds With 1.5g of Experimental Dentifrice. | SMH recovery test was used to assess the changes in mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMH recovery was performed in-vitro and 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 re-hardening of enamel surface. % SMH recovery was calculated from indentation length (micrometer [μm]) of sound enamel specimen at baseline (B), indentation length (μm) after in vitro demineralization (D1), indentation length (μm) after intra-oral exposure (R): [D1-R/D1-B] ×100. | At Baseline and at Day 14 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage Surface Micro Hardness (% SMH) Recovery , of Brushing for 2 Minutes vs. Brushing for 45 Seconds With 0.5g of Experimental Dentifrice. | SMH recovery test was used to assess the changes in mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMH recovery was performed in-vitro and 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 re-hardening of enamel surface. % SMH recovery was calculated from indentation length (μm) of sound enamel specimen at baseline (B), indentation length (μm) after in vitro demineralization (D1), indentation length (μm) after intra-oral exposure (R): [D1-R/D1-B] ×100. | At Baseline and at Day 14 | 
| Percentage Surface Micro Hardness (% SMH) Recovery, of Brushing for 2 Minutes With 0.5g of Experimental Dentifrice vs. Brushing for 2 Minutes With 1.5g of Experimental Dentifrice. | SMH recovery test was used to assess the changes in mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMH recovery was performed in-vitro and 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 re-hardening of enamel surface. % SMH recovery was calculated from indentation length (μm) of sound enamel specimen at baseline (B), indentation length (μm) after in vitro demineralization (D1), indentation length (μm) after intra-oral exposure (R): [D1-R/D1-B] ×100. | At Baseline and at Day 14 | 
| Percentage Surface Micro-hardness Recovery (% SMH), of Brushing for 45 Seconds With 0.5g of Experimental Dentifrice vs. Brushing for 45 Seconds With 1.5g of Experimental Dentifrice. | SMH recovery test was used to assess the changes in mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMH recovery was performed in-vitro and 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 re-hardening of enamel surface. % SMH recovery was calculated from indentation length (μm) of sound enamel specimen at baseline (B), indentation length (μm) after in vitro demineralization (D1), indentation length (μm) after intra-oral exposure (R): [D1-R/D1-B] ×100. | At Baseline and at Day 14 | 
| Percent Surface Micro-hardness (% SMH) Recovery, of Brushing for 2 Minutes With 1.5g of Experimental Dentifrice vs. Brushing for 2 Minutes With 1.5g of an Control Dentifrice. | SMH recovery test was used to assess the changes in mineralization status of enamel specimens using a Wilson 2100 Hardness tester. SMH recovery was performed in-vitro and 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 re-hardening of enamel surface. % SMH recovery was calculated from indentation length (μm) of sound enamel specimen at baseline (B), indentation length (μm) after in vitro demineralization (D1), indentation length (μm) after intra-oral exposure (R): [D1-R/D1-B] ×100. | At Baseline and at Day 14 | 
| Enamel Fluoride Uptake (EFU) After Brushing for 2 Minutes vs. Brushing for 45 Seconds With 1.5g of Experimental Dentifrice. | EFU was measured by using micro-drill analysis of the enamel specimens carried out after 14 days of intra-oral exposure for each of the toothpaste treatments. The amount of fluoride-uptake by enamel was calculated based on the amount of fluoride divided by the area of the enamel cores. | At Day 14 | 
| Enamel Fluoride Uptake (EFU) After Brushing for 2 Minutes vs. Brushing for 45 Seconds With 0.5g of Experimental Dentifrice. | EFU was measured by using micro-drill analysis of the enamel specimens carried out after 14 days of intra-oral exposure for each of the toothpaste treatments. The amount of fluoride-uptake by enamel was calculated based on the amount of fluoride divided by the area of the enamel cores. | At Day 14 | 
| Enamel Fluoride Uptake (EFU) After Brushing for 2 Minutes With 0.5g of Experimental Dentifrice vs. Brushing for 2 Minutes With 1.5g of Experimental Dentifrice. | EFU was measured by using micro-drill analysis of the enamel specimens carried out after 14 days of intra-oral exposure for each of the toothpaste treatments. The amount of fluoride-uptake by enamel was calculated based on the amount of fluoride divided by the area of the enamel cores. | At Day 14 | 
| Enamel Fluoride Uptake (EFU) After Brushing for 45 Seconds With 0.5g of Experimental Dentifrice vs. Brushing for 45 Seconds With 1.5g of Experimental Dentifrice. | EFU was measured by using micro-drill analysis of the enamel specimens carried out after 14 days of intra-oral exposure for each of the toothpaste treatments. The amount of fluoride-uptake by enamel was calculated based on the amount of fluoride divided by the area of the enamel cores. | At Day 14 | 
| Enamel Fluoride Uptake (EFU) After Brushing for 2 Minutes With 1.5g of Experimental Dentifrice vs. Brushing for 2 Minutes With 1.5g of Control Dentifrice. | EFU was measured by using micro-drill analysis of the enamel specimens carried out after 14 days of intra-oral exposure for each of the toothpaste treatments. The amount of fluoride-uptake by enamel was calculated based on the amount of fluoride divided by the area of the enamel cores. | At Day 14 |