In Situ Remineralisation Response of Different Artificial Caries-like Enamel Lesions to Home-care and Professional Fluoride Treatments

Study Overview
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Brief Summary
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This study mainly compared the response of the artificial carious enamel lesions to remineralisation in situ. The tested in vitro demineralising protocols were: MC gel, PA gel, MHDP and Buffer solutions. The lesions were then remineralised in an in situ model, with crossover and double blind design. Fifteen volunteers wore intra-oral appliances containing 2 bovine enamel samples of each demineralising protocol during 3 experimental phases (3 days each). The experimental phases/treatments were: Control (Placebo dentifrice, saliva effect only), Home-care (fluoride dentifrice, 1,100 ppm F, NaF), and Professional/Home-care (varnish- 22,600 ppm F and dentifrice- 1,100 ppm F, NaF). During the 3-day phase, the appliance was only removed during the main meals (four times a day, maximum 1 h duration each, interval between meals 2-3 h). Immediately after the meals, before replacing the appliance in the mouth, the subjects were advised to perform oral hygiene using a soft end-rounded toothbrush (Colgate® 360º Sensitive Pro-Relief TM) and dentifrice (non-fluoridated from IceFresh, Bauru, SP, Brazil or fluoridated dentifrice from Crest Procter & Gamble, Cincinnati, OH, USA) according to the phase and dental floss (Sanifill, São Paulo, Brazil). The remineralising treatment with dentifrices was done ex vivo, 1 min twice a day (after the first and last oral hygiene of the day) using slurry of the dentifrice (1:3 water, 1 drop of solution/specimen). Thereafter, the appliance was replaced in the mouth and the subjects were advised to rinse with 10 ml of water for 5 s and to expectorate. In respect to Professional/Home-care phase, the varnish (Duraphat, Colgate, SP, Brazil) was applied before the in situ study for 6h and then removed. The enamel remineralization was quantified using transverse microradiography (% mineral recovery and lesion depth, TMR), surface and cross-sectional hardness. The data were submitted to statistical analysis (p<0.05).

Conditions
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Dental Caries

Intervention / Treatment
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* Other: Application of fluoride varnish (22600 ppm F, Duraphat) at the begining of the study
* Other: Application of fluoride toothpaste (1500 ppm F, Crest) twice a day for 3 days of the study
* Other: Application of placebo toothpaste (0 ppm F, Ice Fresh) twice a day for 3 days of the study


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: a stimulated physiological salivary flow rate of >1 ml.min-1 a non-stimulated physiological salivary flow rate of >0.25 ml.min-1 good oral health (i.e. no cavities or significant gingivitis/periodontitis) Exclusion Criteria: systemic illness pregnancy or breastfeeding use of fixed or removable orthodontic appliances use of fluoride mouthrinse or professional fluoride application in the last 2 months.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Fluoride varnish and fluoride toothpaste<br>Application of fluoride varnish (Duraphat) at the begining of the study. Application of fluoride toothpaste (Crest) twice a day for 3 days. | Other: Application of fluoride varnish (22600 ppm F, Duraphat) at the begining of the study<br> <br> Other: Application of fluoride toothpaste (1500 ppm F, Crest) twice a day for 3 days of the study<br> <br> |
| Placebo Comparator: placebo toothpaste<br>Application of placebo toothpaste twice a day for 3 days | Other: Application of placebo toothpaste (0 ppm F, Ice Fresh) twice a day for 3 days of the study<br> <br> |
| Active Comparator: Fluoride toothpaste<br>Application of fluoride toothpaste (Crest) twice a day for 3 days | Other: Application of fluoride toothpaste (1500 ppm F, Crest) twice a day for 3 days of the study<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The increase of mineral content (% mineral volume) using transverse microradiography |  | 3 days | 
| The increase of hardness (KHN or KgF/mm2) artificial caries lesions using surface and cross-sectional hardness |  | 3 days | 
| Decrease of lesion depth (microns) of artificial caries lesions using transverse microradiography |  | 3 days |