Modeling the Effects of Cyclical Masticatory Forces in a 3D Oral Mucosal Model <i>in Vitro</i>

This study describes the development of a three-dimensional (3D) oral mucosal model (OMM) to investigate how oral tissues respond to masticatory forces. The OMMs replicated key features of human oral mucosa, such as stratified keratinocyte telomerase-immortalized gingival keratinocytes (TIGK) layers and fibroblast-populated collagen matrices. Cyclical mechanical forces (0-10 N) for 2 h applied to the model caused force-dependent changes in the histological structure, including thinning of the epithelium and collagen matrix and cell displacement at higher forces. Lactate dehydrogenase (LDH) cytotoxicity assays revealed that 10 N forces led to significant cell damage (about 50% cell death) in TIGK monolayers, whereas lower forces (1-5 N) caused minimal damage. OMMs showed reduced cell death (∼15% at 10 N), indicating better resilience presumably due to their 3D architecture. Additionally, force-dependent increases in the release of the proinflammatory cytokines IL-6 and IL-8 were observed, with lower responses in OMMs compared with monolayer cultures. This study demonstrates that OMMs can be used to model the effects of masticatory forces on the response of the oral mucosa in denture wearers and has been utilized to investigate the effects of a denture adhesive on the inflammatory response of the OMM to pressure.