New In Situ Model Design for Caries and Erosion

NCT07849270 | Active Not Recruiting Phase 3 FDA Drug FDA Device

• 1 other identifier: 31100
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

This study will test simultaneously and independently two novel in situ models, one for caries and one for erosive tooth wear (ETW), based on the simulation of these dental conditions on enamel specimens placed on 3D-printed mandibular appliances. Caries simulation will be done on the right side (color-coded blue) of the appliance, while ETW on the left side (color-coded red) and their outcomes evaluated independently. The study aims at testing the safety, compliance and F-efficacy (dose-response) of the models. The study will follow a double-blind, single-center, 3-way within-subject crossover design. Treatments will consist of dentifrices, or toothpastes, (1150 ppm F as sodium fluoride, 250 ppm F as sodium fluoride and 0 ppm F/Negative Control) used twice a day.

Conditions

Caries; Erosive Tooth Wear

Keywords

cavities; gum recession

Outcome Measures

Primary Outcomes (2)

• Mean Percent Surface Microhardness (SMH) Recovery

  Description: The SMH test will be used to assess changes in the mineral status of partially demineralized enamel specimens. SMH will be measured using a Wilson 2100 Hardness Tester. The extent of remineralization will be calculated based on the Gelhard et al. method of %SMH recovery = (D1-R)/(D1-B) x 100 where: B = indentation length (µm, micrometer) of sound enamel specimen at baseline D1 = indentation length (µm) after in vitro demineralization R = indentation length (µm) after intra-oral exposure.

  Days 14 and 21 of each of the three consecutive treatment periods (each treatment period is 21 days)

• Surface Loss

  Measurements of enamel surface wear respective to the metal holder reference surfaces will be made on impressions of the specimens taken at baseline and after 7, 14 and 21 days of study. The impression of each specimen will be carefully cut with the aid of a scalpel and positioned on the profilometer with double adhesive tape for the scan. The parameters for the scan of both specimens and impressions will consist of step size set at 0.02 mm and number of steps at 200, in both x and y directions. The total area scanned will be 3 mm x 3 mm round specimens. With the use of dedicated software, the depth of the treated area will be calculated based on the reference surfaces. A 3-point height tool will be applied. Profile scans generated from impressions will be inverted (using the software) before analysis, in order to provide outcome data of surface loss (micrometers).

  Days 14 and 21 of each of the three consecutive treatment periods (each treatment period is 21 days)

Secondary Outcomes (6)

• Mean Enamel Fluoride Uptake

  Days 14 and 21 of each of the three consecutive treatment periods (each treatment period is 21 days)

• Mean Net Acid Resistance

  Days 14 and 21 of each of the three consecutive treatment periods (each treatment period is 21 days)

• Mean Comparative Acid Resistance

  Days 14 and 21 of each of the three consecutive treatment periods (each treatment period is 21 days)

• Transervse Microradiography (TMR) - Integrated Mineral Loss

  Days 14 and 21 of each of the three consecutive treatment periods (each treatment period is 21 days)

• Transverse Microradiography (TMR) - Lesion Depth

  Days 14 and 21 of each of the three consecutive treatment periods (each treatment period is 21 days)

Other Outcomes (1)

• Treatment Compliance

  Day 21 of each of three consecutive treatment periods (each treatment period is 21 days)

Study Arms (3)

0 ppm F toothpaste

PLACEBO COMPARATOR

Participants will use toothpaste containing 0 ppm fluoride.

Drug: 0 ppm fluoride toothpaste; Device: Mandibular intraoral appliance

250 ppm F toothpaste

ACTIVE COMPARATOR

Participants will use toothpaste containing 250 ppm fluoride.

Drug: 250 ppm fluoride toothpaste (dose-response control); Device: Mandibular intraoral appliance

1150 ppm F toothpaste

ACTIVE COMPARATOR

Participants will use toothpaste containing 1150 ppm fluoride.

Drug: 1150 ppm fluoride toothpaste; Device: Mandibular intraoral appliance

Interventions

0 ppm fluoride toothpaste DRUG

Toothpaste containing 0 ppm fluoride (F)

0 ppm F toothpaste

250 ppm fluoride toothpaste (dose-response control) DRUG

Toothpaste containing 250 ppm fluoride, as NaF (sodium fluoride)

250 ppm F toothpaste

1150 ppm fluoride toothpaste DRUG

Marketed toothpaste product containing 1150 ppm fluoride, as NaF (sodium fluoride)

1150 ppm F toothpaste

Mandibular intraoral appliance DEVICE

After impressions of both dental arches are taken, a mandibular appliance consisting of a 3D-printed metal frame and acrylic buccal flanges (blue on the right and red on the left) will be made. The appliance will be tested and adjusted for optimal fit and comfort before the experimental phase of the study. At each testing period, 4 gauze-covered 4-millimeter round partially demineralized human enamel specimens will be placed in the right buccal acrylic flange (blue, caries) side of the mandibular appliance and 4 sound human enamel specimens previously mounted on 3 millimeter round metal holders will be placed on the other acrylic flange (red, ETW) side of the same appliance. Subjects will wear their appliance 24 hours a day, except during study procedures, meals/snacks, and drinking (e.g. milk, juice, sports drinks, tea, etc.) except water.

0 ppm F toothpaste; 1150 ppm F toothpaste; 250 ppm F toothpaste

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• In order to participate subjects must:
• Provide voluntary, written informed consent;
• Be between 18 and 65 years old;
• Understand and be willing, able and likely to comply with all study procedures and restrictions;
• Be willing and capable of wearing a custom-made removable mandibular appliance 24 hours a day for three (3), three-week treatment periods;
• Be in good medical and dental health with no active caries or periodontal disease; Note: subjects presenting at screening with caries may continue in the study if their carious lesions are restored prior to beginning treatment 1; and,
• Have a salivary flow rate in the range of normal values (unstimulated whole saliva flow rate ≥ 0.2 mL/min; gum base stimulated whole saliva flow rate ≥ 0.8 mL/min);
• Have an adequate number of teeth and space to accommodate the custom-made removable mandibular appliance, as per the study PI/study dentist's discretion.

You may not qualify if:

• No subject may:
• Be pregnant, intending to become pregnant during the study period or breast feeding;
• Have any medical condition that could be expected to interfere with the subject's safety during the study period (including temporomandibular disorders);
• Be taking antibiotics during the study period, or have taken antibiotics in the two weeks prior to the beginning treatment 1;
• Participated in another clinical study or receipt of an investigational drug within 30 days of beginning treatment 1;
• Be taking fluoride supplements, required to use a fluoride mouthrinse or have received a professional fluoride treatment in the two weeks preceding specimen placement; or,
• Have a history of metal allergies.

Sponsors & Collaborators

• Indiana University: lead

Study Sites (1)

Oral Health Research Institute of the Indiana University School of Dentistry

Indianapolis, Indiana, 46202, United States

Location

Related Publications (1)

• Rikvold PT, Kambourakis Johnsen K, Leonhardt D, Mollebjerg A, Nielsen SM, Skov Hansen LB, Meyer RL, Schlafer S. A New Device for In Situ Dental Biofilm Collection Additively Manufactured by Direct Metal Laser Sintering and Vat Photopolymerization. 3D Print Addit Manuf. 2023 Oct 1;10(5):1036-1045. doi: 10.1089/3dp.2022.0009. Epub 2023 Oct 10.

  PMID: 37886402 BACKGROUND

MeSH Terms

Conditions

Gingival Recession

Condition Hierarchy (Ancestors)

Gingival Diseases; Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Periodontal Atrophy

Study Officials

• Anderson Hara, DDS, PhD

  Indiana University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The participants, investigator, and outcomes assessor are aware of the fluoride composition of all three study toothpastes. However, because participants will be exposed to all three of the study toothpastes in a randomly assigned treatment order, the participants, the study dentist, and the laboratory technicians responsible for performing the outcome measurements will be blinded to the assigned order of the toothpastes.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director, Oral Health Research Institute

Model Details: Each participant will be randomly assigned to a treatment order sequence. Each participant will complete all three treatment regimens, one treatment regimen in each of the three treatment periods.

Study Record Dates

• First Submitted: August 31, 2026
• First Posted: September 30, 2026
• Study Start: August 3, 2026
• Primary Completion (Estimated): January 29, 2027
• Study Completion (Estimated): January 29, 2027
• Last Updated: September 30, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)