A proof-of-principle bite force study using two experimental test denture adhesives and a currently marketed denture adhesive

Objectives: This proof-of-principle, single-center, randomized, examiner-blind, crossover study compared two experimental polyvinyl acetate (PVA)-based denture adhesives (Test Adhesives 1 and 2) with a marketed reference polymethyl vinyl ether/maleic anhydride (PMV/MA)-based adhesive and no adhesive using incisal bite force area over baseline over 12 hr (AOB_0–12) in participants with an at least moderately well-fitting complete maxillary denture. Previous in vitro studies suggested the experimental denture adhesives provided superior performance. Materials and Methods: Participants were randomized to a treatment sequence such that each received each treatment once. Prior to treatment application (baseline) and at 0.5, 1, 3, 6, 9, and 12 hr following the application, participants bit on a force transducer until their maxillary denture dislodged. Between-treatment differences in AOB_0–12 were analyzed using analysis of covariance. For study validity, the reference adhesive was compared with no adhesive. Participants were asked to rate sensory experiences and ease of denture removal. Results: Twenty-three participants were included in the modified intent-to-treat population. Although Test Adhesives 1 and 2 had a higher mean AOB_0–12 than no adhesive, differences were not statistically significant. No statistically significant difference was also found between the reference adhesive and no adhesive; hence, study validity was not attained. Participants did not report any clear differences between the test or reference adhesives in terms of taste or feel; however, dentures were easier to remove with the test adhesives versus reference. No treatment-related adverse events were reported. Conclusion: Neither the experimental PVA-based denture adhesives nor the PMV/MA-based reference product demonstrated a statistically significant difference in incisal bite force AOB_0-12 compared with no adhesive. The reasons for these unexpected results is unclear; they suggest that findings of in vitro tests for denture adhesive performance are not always translated to in vivo performance (Clinicaltrials.gov: NCT02937870).