Intra Oral Appliance (IOA) Model Evaluating the Efficacy of Sensitive Toothpaste

Intra Oral Appliance (IOA) Model Evaluating the Efficacy of Three Dentifrices on Enamel Lesion Remineralization

This single-center, randomized, double-blind, three-period crossover in situ study evaluated the enamel remineralization potential and fluoride bioavailability of three dentifrices: a fluoride-free negative control, a positive control with 0.243% sodium fluoride, and an investigational dentifrice containing 0.243% sodium fluoride, 5.0% potassium nitrate (KNO₃), and 20% sodium bicarbonate. Adult subjects wore acrylic palatal appliances containing demineralized enamel specimens for three 7-day treatment periods, each preceded by a 5-day fluoride-free washout. Primary outcomes were percent surface microhardness recovery (%SMHR) and enamel fluoride concentration.

Study Overview

• Status: Completed
• Conditions: Dental Caries
• Intervention / Treatment: Drug: Negative Control Toothpaste; Drug: Active Comparator; Drug: Test toothpaste

Detailed Description

This in situ intraoral appliance (IOA) model evaluates anticaries potential by exposing demineralized enamel specimens to oral conditions while allowing for ex vivo treatment assessments. Subjects wore acrylic palatal appliances containing four enamel specimens covered with steel gauze to promote plaque formation. Each of the three treatment periods lasted seven days and included twice-daily toothbrushing and dentifrice slurry swishing, plus three daily sucrose challenges. A minimum 5-day fluoride-free washout preceded each period. Post-treatment specimens were analyzed for %SMHR and enamel fluoride concentration.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Indiana
    • Noblesville, Indiana, United States, 46060
      • Therametric Technologies, Inc.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults ≥18 years
• Good general and oral health
• Normal unstimulated saliva flow (≥1.5 mL unstimulated saliva in 5 minutes)
• ≥16 teeth and functional maxillary dentition to support palatal appliance
• Agree to abstain from other oral care products and preventive dental procedures during study
• No advanced periodontal disease, no visible untreated caries
• If female, not pregnant or breastfeeding (self-reported)
• No significant oral soft tissue pathology; no peri/oral piercings; no removable partial dentures
• No antibiotics or immunosuppressives within 30 days of screening
• No palatal torus; no medical condition that would interfere with safety
• No allergy or significant adverse events to impression materials, acrylics, or common oral product

Exclusion Criteria:

• Unable to tolerate appliance or comply with procedures
• Oral pathology that interferes with participation
• Use of fluoride toothpaste during washout periods
• Participation in another appliance study within the last 4 week

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Negative Control Toothpaste; Fluoride-free dentifrice (0 ppm fluoride). Used for twice-daily brushing and slurry swishing per protocol during each 7-day test period.	Drug: Negative Control Toothpaste; Fluoride-free toothpaste
Active Comparator: Comparator; Sodium fluoride dentifrice (0.243% sodium fluoride). Used for twice-daily brushing and slurry swishing per protocol during each 7-day test period.	Drug: Active Comparator; Commercially available fluoride toothpaste
Experimental: Test Toothpaste; Test dentifrice containing 0.243% sodium fluoride, 5.0% potassium nitrate, and 20% sodium bicarbonate. Used for twice-daily brushing and slurry swishing per protocol during each 7-day test period.	Drug: Test toothpaste; Investigational fluoride toothpaste

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent Surface Microhardness Recovery (%SMHR)		End of each 7-day test period (three periods total)
Enamel Fluoride Concentration (EFU)	Post-treatment enamel fluoride concentration (µg F/cm³)	End of each 7-day test period (three periods total)

Collaborators and Investigators

• Sponsor: Church & Dwight Company, Inc.
• Investigators: Study Director: Annahita Ghassemi, PhD, Church & Dwight, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): April 15, 2025
• Primary Completion (Actual): June 10, 2025
• Study Completion (Actual): June 10, 2025

Study Registration Dates

• First Submitted: February 12, 2026
• First Submitted That Met QC Criteria: February 12, 2026
• First Posted (Actual): February 19, 2026

Study Record Updates

• Last Update Posted (Actual): February 19, 2026
• Last Update Submitted That Met QC Criteria: February 12, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Tooth Demineralization; Dental Caries
• Other Study ID Numbers: ST-25-U04

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The sponsor does not plan to share individual participant data (IPD) from this study. Summary results will be provided as required; de-identified datasets or additional supporting documents will not be made available.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No