Randomization
HYPERSENSITIVITY
Participants were assigned to each experimental group using a block randomization scheme stratified according to the severity of hypersensitivity. Severity was determined by the average Schiff sensitivity score (mild, 1.167–1.5; moderate: 1.57–1.857, severe: 1.9–2.625) during the screening session. Finally, the 53 participants were randomly divided into three experimental groups. There were 17 subjects in Group N, 18 in Group SC, and 18 in Group TP.