Oral microbiota bacteria form biofilms that can cause periodontitis when they become dysbiotic. With a mixed inoculum consisting of 14 different bacterial species that inhabit the oral cavity, we cultivated distinct biofilms in in vitro model systems and characterized them rheologically. By growing biofilms under anaerobic or microaerophilic conditions, we obtained two different compositions of the microbial community, but were unable to uniquely attribute the structure to dysbiotic or symbiotic dental biofilms. Using an oscillatory amplitude test, we characterized their rheological response in the linear and nonlinear range. The results show that anaerobically grown biofilms have a higher gel structure strength, structural collapse occurs at higher shear deformations, after the initial collapse the structure collapses more quickly, and they have greater intracyclic shear softening and greater shear stiffening with increasing shear deformation. The obtained results lay a good foundation for optimizing in vitro models of dental biofilms in the future.
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