Statement of problem The advantages and disadvantages of frequently changing sides while masticating remain unclear. Purpose The purpose of this clinical study was to determine the effect of varying the frequency of masticatory side switches on masticatory mixing ability and sensory perception in dentate adults. Material and methods This nonblinded, randomized 12-period crossover study, conducted at Barcelona Dental School from January to March 2022, included 36 healthy adults with natural dentitions (median age, 23.5 years; 26 women). Participants were randomly allocated to 12 sequences and performed 12 masticatory assays masticating a 2-colored gum for 40 cycles each using the following masticatory styles as interventions: freestyle, unilateral right, unilateral left, and switching sides 5%, 15%, and 25%. The primary outcome was the mixing ability index (MAI), defined as the standard deviation of the red channel intensity of the masticated gum in the color-histogram plugin of the ImageJ software program. Participants also rated the perceived flavor intensity and salivary flow on a visual analog scale. Data were analyzed by repeated measures analysis of variance (α=.05). Results The MAI was similar for all masticatory styles (P=.63). Participants perceived greater flavor intensity (mean difference: 8%, 95% CI: 1% to 15%) and salivary flow (mean difference: 11%, 95% CI: 0% to 21%) with 25% side switching compared with freestyle or unilateral mastication. Conclusions Frequently switching the masticatory side while masticating gum does not alter the mixing ability, but it appears to enhance salivary flow and flavor intensity.

This in vitro study evaluated the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic molar tubes bonded using conventional, hydrophilic, and self-etch adhesives under dry and saliva-contaminated conditions, while also assessing the impact of shear force direction. Extracted molars were bonded with Transbond XT™ (T), Transbond MIP™ (M), or Scotchbond Universal™ (S) under dry or saliva-contaminated conditions. Debonding was performed at 90° or 45°, introducing a clinically relevant but underexplored variable in orthodontic bond-strength testing. ARI scores were assessed via stereomicroscopy and visual inspection. Statistical tests (Kruskal–Wallis and Mann–Whitney) showed no significant SBS differences among adhesives under identical conditions (p > 0.05). However, all adhesives exhibited significantly reduced SBS under saliva contamination (p < 0.001; T: 5.4 vs. 4.1 MPa; M: 5.7 vs. 3.6 MPa; S: 5.5 vs. 4.5 MPa). In dry conditions, SBS was significantly higher with 45° debonding (p < 0.05). Under contamination, SBS varied by ARI score (p = 0.05), with ARI 0 specimens showing higher SBS than ARI 3. These findings confirm that moisture reduces bond strength across adhesive types, while 45° force application enhances SBS under dry conditions. ARI score variability under contamination may reflect complex failure modes.