Experimental Dentifrice Remineralization/Fluoride Uptake in an in Situ Model

Phase 2

Completed

Interventions: Drug: NaF Dentifrice
Other: Placebo Dentifrice
Drug: NaF/ KNO3/isopentane Dentifrice
Drug: NaF/KNO3 Dentifrice

Brief Summary: The purpose of this study is to determine whether an experimental fluoridated dentifrice is effective in the treatment of dental caries

Detailed Description: Topical fluorides have been proven to be clinically effective in the prevention of dental caries. It is generally agreed that anti-caries effect of fluoride (F) is mainly by decreasing the rate of enamel demineralization and enhancing the rate of enamel remineralization. An in-situ Surface Micro-hardness (SMH) test is widely used to evaluate enamel demineralization and remineralization during the caries process. Determination of fluoride uptake in-situ also provides better estimation of true fluoride bioavailability of fluoride dentifrice products. In this study, an in-situ remineralization fluoride uptake model will be used to compare the efficacy of experimental dentifrice with a marketed dentifrice and placebo dentifrice. Participants wore partial dentures containing two partially demineralized enamel specimens for two weeks- 24 hours per day, except when brushing (twice daily) with test dentifrice. Following each treatment period, the enamel specimens were analyzed for SMH recovery and fluoride uptake through microdrill enamel biopsy technique.

Recruitment & Eligibility

Inclusion Criteria

Age: Aged between 18 and 78
Fluoride: Currently living in the Indianapolis area which has a fluoridated water supply (1 ppm F) and not taking fluoride supplements for medical reasons
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 x 7 mm). Willing and capable of wearing their removable partial dentures 24 hours per day during the experimental periods
Dental health:Have no current active caries or periodontal disease that may compromise the study or the health of the participants and 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/min; gum base stimulated whole saliva flow rate ≥ 0.8 mL/min
Compliance: Understands and is willing, able and likely to comply with all study procedures and restrictions
Consent:Demonstrates understanding of the study and willingness to participate as evidenced by voluntary written informed consent and has received a signed and dated copy of the informed consent form
General Health: Good general health with (in the opinion of the investigator) no clinically significant and/or relevant abnormalities of medical history or oral examination that could interfere with participant safety during the study period

Exclusion Criteria

Antibiotics:Currently taking antibiotics or have taken antibiotics in the two weeks prior to the screening visit
Allergy/Intolerance:Known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients
Pregnancy:Women who are known to be pregnant or who are intending to become pregnant over the duration of the study.
Breast-feeding:Women who are breast-feeding.
Clinical Study/Experimental Medication: Participation in another clinical study or receipt of an investigational drug within 30 days of the screening visit
Personnel:An employee of the sponsor or the study site who is directly involved in the study

Arm && Interventions

Group	Intervention	Description
NaF Dentifrice	NaF Dentifrice	Participants to brush their teeth for one timed minute twice daily with a dentifrice containing 1450 ppm F as NaF.
Placebo Dentifrice	Placebo Dentifrice	Participants to brush their teeth for one timed minute twice daily with a fluoride free dentifrice (0 ppm F).
Sodium fluoride/potassium nitrate/Isopentane dentifrice	NaF/ KNO3/isopentane Dentifrice	Participants to brush their teeth for one timed minute twice daily with a gel to foam dentifrice containing active ingredients: 1450 ppm F as sodium fluoride (NaF) and 5% potassium nitrate (KNO3) and isopentane as an excipient ingredient.
NaF/KNO3 Dentifrice	NaF/KNO3 Dentifrice	Participants to brush their teeth for one timed minute twice daily with a gel to foam dentifrice, containing as active ingredients: 1450 ppm NaF and 5% KNO3 but no isopentane.

Primary Outcome Measures

Name	Time	Method
Percentage Surface Micro-hardness Recovery (SMHR) of Enamel Specimens	Baseline to 14 days	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 re-hardening of enamel surface. Percent SMHR was calculated from indentation values of enamel specimens at baseline (B), after intra-oral exposure (R) and after in-vitro demineralization (D) using formula: \[(D-R)/ (D-B)\]\*100.

Secondary Outcome Measures

Name	Time	Method
Adjusted Mean Change From Baseline in Enamel Fluoride Uptake	Baseline to 14 days	Enamel fluoride uptake was determined using the microdrill enamel biopsy technique. The amount of fluoride uptake by enamel was calculated based on the amount of fluoride (F) divided by the area of the enamel cores and expressed as ug\*F/cm\^3. The difference between treatments was calculated with respect to fluoride uptake by enamel.