Statistical analysis
Statistical analysis was performed using IBM SPSS Statistics for Windows, version 27 (IBM Corp., Armonk, N.Y., USA). A one-way analysis of variance was performed for each test substance at each time and for each substance at each time point. Tukey’s method was then used to analyse whether each test substance changed over time and whether there was a difference in retentive force between substances at each time point. A one-way analysis of variance was performed on the results of the subjective evaluation of usability. Tukey’s method was used to analyse whether there was a difference in usability among the substances for each question item. All significance levels were set at 5%. The null hypotheses were that the retentive force does not change with time, that the retentive force changes with the type of substance, and that the usability does not change with the type of substance.