The purpose of this study is to investigate the ability of an experimental dentifrice containing 1150 parts per million (ppm) fluoride to remineralize acid-softened dental enamel and help prevent further demineralization compared to a 0 ppm fluoride placebo dentifrice and a marketed, fluoride-containing dentifrice (Reference Dentifrice).
This will be a randomized, controlled, single center, single-blind, 3 period, 3 treatment, cross-over, in situ design study. Previously demineralized bovine enamel specimens will be placed intra orally using a palatal appliance and the remineralizing performance of the experimental, reference and placebo dentifrices will be evaluated at 4 and 12 hours post toothbrushing, based on surface micro hardness measurements of the bovine enamel specimens. At each treatment visit, once the palatal the appliance is fitted in the mouth, a five minute equilibration period will ensue following which each participant will brush their teeth with their assigned product. Participants will remove the appliance for 30 minutes at 4 and 8.5 hours post brushing and will remove and store the appliance 13 hours post brushing (12 hours intraoral exposure). Sufficient participants will be screened to randomize approximately 33 participants to study treatment to ensure approximately 30 participants complete the study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
33
Dentifrice containing 1150 ppm fluoride and 5% KNO3.
Dentifrice containing 0 ppm fluoride and 5% KNO3.
Dentifrice containing 1100 ppm fluoride as SnF2.
Oral Health Research Institute
Indianapolis, Indiana, United States
Adjusted Mean Percent Surface Microhardness Recovery (%SMHR) at 4 Hours (Test Dentifrice Versus (vs.) Placebo Control Dentifrice)
%SMHR was used to measure the ability of the dentifrice to remineralize enamel. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and the extent of remineralization was evaluated using surface microhardness (SMH) technique to yield the %SMHR. The enamel specimens were evaluated both prior to and after intra-oral exposure and indentation lengths were measured. The %SMHR was derived as \[(E1-R)/(E1-B)\] \* 100 where: B = indentation length (micrometre \[μm\]) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), R = indentation length (μm) after 4 hours in situ remineralization.
Time frame: At 4 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean Percent Relative Erosion Resistance (%RER) at 4 Hours (Test Dentifrice vs. Placebo Control Dentifrice)
%RER was used to measure the ability of the dentifrice to protect enamel from further acid-induced demineralization by both acid protection and remineralization. SMH technique was used to calculate %RER. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and further treated with acid ex situ followed by additional SMH evaluations to calculate %RER. The %RER was derived as \[(E1-E2)/(E1-B)\] \* 100 where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), E2 = indentation length (μm) after second erosive challenge (with a commercially available grapefruit juice).
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Time frame: At 4 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean %SMHR at 4 Hours (Test Dentifrice vs. Reference Dentifrice)
%SMHR was used to measure the ability of the dentifrice to remineralize enamel. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and the extent of remineralization was evaluated using surface SMH technique to yield the %SMHR. The enamel specimens were evaluated both prior to and after intra-oral exposure and indentation lengths were measured. The %SMHR was derived as \[(E1-R)/(E1-B)\] \* 100 where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), R = indentation length (μm) after 4 hours in situ remineralization.
Time frame: At 4 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean %SMHR at 12 Hours
%SMHR was used to measure the ability of the dentifrice to remineralize enamel. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and the extent of remineralization was evaluated using SMH technique to yield the %SMHR. The enamel specimens were evaluated both prior to and after intra-oral exposure and indentation lengths were measured. The %SMHR was derived as \[(E1-R)/(E1-B)\] \* 100 where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), R = indentation length (μm) after 12 hours in situ remineralization.
Time frame: At 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean %RER at 4 Hours (Test Dentifrice vs. Reference Dentifrice)
%RER was used to measure the ability of the dentifrice to protect enamel from further acid-induced demineralization by both acid protection and remineralization. SMH technique was used to calculate %RER. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and further treated with acid ex situ followed by additional SMH evaluations to calculate %RER. The %RER was derived as \[(E1-E2)/(E1-B)\] \* 100 where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), E2 = indentation length (μm) after second erosive challenge (with a commercially available grapefruit juice).
Time frame: At 4 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean %RER at 12 Hours
%RER was used to measure the ability of the dentifrice to protect enamel from further acid-induced demineralization by both acid protection and remineralization. SMH technique was used to calculate %RER. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and further treated with acid ex situ followed by additional SMH evaluations to calculate %RER. The %RER was derived as \[(E1-E2)/(E1-B)\] \* 100 where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), E2 = indentation length (μm) after second erosive challenge (with a commercially available grapefruit juice).
Time frame: At 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean Enamel Fluoride Uptake (EFU) at 4 and 12 Hours
EFU is a measure of how much fluoride has been incorporated into the enamel during the process of remineralization. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and chemically analyzed to measure the amount of fluoride incorporated into the enamel by the dentifrice treatment.
Time frame: At 4 and 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean Acid Resistance Ratio (ARR) at 4 and 12 Hours
ARR was used to measure the resistance of the remineralized enamel to further acid softening. SMH technique was used to calculate ARR. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and further treated with acid ex situ followed by additional SMH evaluations to calculate ARR. The ARR was derived as 1 - \[(E2-R)/(E1-B)\] where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), E2 = indentation length (μm) after second erosive challenge (with a commercially available grapefruit juice), R = indentation length (μm) after 4 and 12 hours in situ remineralization.
Time frame: At 4 and 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean %SMHR at 4 and 12 Hours (Reference Dentifrice vs Placebo Control Dentifrice)
%SMHR was used to measure the ability of the dentifrice to remineralize enamel. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatment in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and the extent of remineralization was evaluated using SMH technique to yield the %SMHR. The enamel specimens were evaluated both prior to and after intra-oral exposure and indentation lengths were measured. The %SMHR was derived as \[(E1-R)/(E1-B)\] \* 100 where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), R = indentation length (μm) after 4 and 12 hours in situ remineralization.
Time frame: At 4 and 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean %RER at 4 and 12 Hours (Reference Dentifrice vs Placebo Control Dentifrice)
%RER was used to measure the ability of the dentifrice to protect enamel from further acid-induced demineralization by both acid protection and remineralization. SMH technique was used to calculate %RER. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and further treated with acid ex situ followed by additional SMH evaluations to calculate %RER. The %RER was derived as \[(E1-E2)/(E1-B)\] \* 100 where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), E2 = indentation length (μm) after second erosive challenge (with a commercially available grapefruit juice).
Time frame: At 4 and 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean EFU at 4 and 12 Hours (Reference Dentifrice vs Placebo Control Dentifrice)
EFU is a measure of how much fluoride has been incorporated into the enamel during the process of remineralization. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and chemically analyzed to measure the amount of fluoride incorporated into the enamel by the dentifrice treatment.
Time frame: At 4 and 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)
Adjusted Mean ARR at 4 and 12 Hours (Reference Dentifrice vs Placebo Control Dentifrice)
ARR was used to measure the resistance of the remineralized enamel to further acid softening. SMH technique was used to calculate ARR. Previously demineralized, sterilized bovine enamel specimens were placed intra orally using a palatal appliance. The enamel specimens were exposed to the dentifrice treatments in the mouth during the treatment application and allowed to remineralize intra orally under the action of the participant's saliva. The specimens were then removed from the palatal appliance and further treated with acid ex situ followed by additional SMH evaluations to yield ARR. The ARR was derived as 1 - \[(E2-R)/(E1-B)\] where: B = indentation length (μm) of sound enamel at baseline, E1 = indentation length (μm) after first erosive challenge (with a commercially available grapefruit juice), E2 = indentation length (μm) after second erosive challenge (with a commercially available grapefruit juice), R = indentation length (μm) after 4 and 12 hours in situ remineralization.
Time frame: At 4 and 12 hours of intra-oral exposure following treatment on Day 1 of each treatment period (each treatment period was of 2 days with 3 days washout in between)