Intraoral devices preparation and instructions for participants
For each participant, two oral acrylic resin devices were obtained from the
impression (Jeltrate Plus, Dentsply Sirona, York, PA, USA) of the maxillary arch
(Each toothpaste was packed in 30 g tubes identical in appearance by a researcher,
different from the operator so that neither he nor the participant knew which
toothpaste was being used, as recommended in a double-blind study. As a
randomized and crossover study, all the participants were randomly assigned to
brush the enamel fragments with all the toothpastes. The participants used one
toothpaste on each side of the device (each side containing two fragments) for
30 days, and a washout period of 7 days was established before and between the
treatments 
