Related Experiment Video
Updated: Feb 13, 2026

Randomized, Triple-Blind, and Parallel-Controlled Trial of Transcranial Direct Current Stimulation for Cognitive Rehabilitation after Stroke
Published on: June 6, 2025
A randomized triple-blind crossover trial of a hydrocolloid-containing dentifrice as a controlled-release system for
Vanessa Feitosa Alves1, Vanderlúcia Gomes Moreira2, Andréia Felix Soares2
1Department of Clinical and Social Dentistry, Federal University of Paraiba, Castelo Branco, s/n., João Pessoa, Paraiba, 58051-900, Brazil. vanessafalves@hotmail.com.
Objective:
To evaluate retention of intraoral fluoride in biofilm and saliva, an experimental dentifrice containing hydrocolloid (tara gum) was used as a controlled-release system for fluoride (F).
Materials And Methods:
In a triple-blind randomized crossover trial with washout, 18 individuals used the following different dentifrices for a week: 100-TGF (sodium fluoride NaF associated with tara gum, 1100 mg/L), 50-TGF (50% NaF associated with tara gum + 50% free NaF, 1100 mg/L), PC (free NaF, 1100 mg/L), TG (with tara gum and without F), and placebo (without F or tara gum). On the seventh day of dentifrice use, biofilm was collected at 1 and 12 h, and saliva was collected up to 60 min and 12 h after the last toothbrushing. F concentrations were determined by physico-chemical analysis of fluoride using the hexamethyldisiloxane-facilitated diffusion technique. Data were subjected to two-way analysis of variance (repeated measures) and Spearman's correlation coefficient (p < 0.05) testing.
Results:
No significant difference was observed with the same dentifrice regarding F retention in biofilm at 1 and 12 h after toothbrushing for the 100-TGF, placebo, and TG groups (p > 0.05). The highest area under the curve values in saliva were found for the 50-TGF, 100-TGF, and PC groups.
Conclusion:
The dentifrice containing hydrocolloid as a controlled-release system for F promoted F retention in the oral cavity, even at 12 h after brushing.
Clinical Relevance:
Hydrocolloid added to dentifrices as a controlled-release system for F might contribute to a higher anti-caries effect.
Trial Registration:
NCT02809014.
More Related Videos
Related Concept Videos
Blind Procedures
Blinding
Crossover Experiments
Crossover designs are performed even with smaller sample sizes since the samples can act as their controls. These are better than simple randomized trials since patients are exposed to all the treatments.
Trial and Error and Algorithm
Clinical Trials: Overview
Clinical Trials
There are four phases in a clinical trial. A phase one...

