Gingival stiffness affects susceptibility to inflammation, according to new study

“We discovered that soft gingiva results in inflammation and hinders the development of gingival fibres,” said  Dr Masahiro Yamada, study author and associate professor at the Tohoku University's Graduate School of Dentistry.

It has long been known that individuals with thick or stiff gingiva are less susceptible to gingival recessions. Many factors can lead to gingival recession, such as periodontal disease, over-brushing, and chewing tobacco. However, this is the first time that gingival stiffness has been attributed to biological reactions.

Although fibroblasts play an important role in the maintenance, repair and healing of the gingiva, they also produce various inflammatory and tissue-degrading biomolecules which degrade the gingival fibres. In addition, fibroblasts are associated with immune responses to pathogens.

Dr Yamada, along with his colleague Prof. Hiroshi Egusa, also from the Tohoku University's Graduate School of Dentistry, created an artificial culture environment that simulated soft or hard gingiva and cultured human gingival fibroblasts on them. They discovered that hard gingiva-simulated stiffness activated an intracellular anti-inflammatory system in the gingival fibroblasts that prevented inflammation. Yet, soft gingiva-simulated stiffness suppressed the fibroblastic anti-inflammatory system. This increased the likelihood of inflammation and resulted in less collagen synthesis.

“Our research is the first to demonstrate the biological mechanisms at play in regard to a patient's gingival properties,” Dr Yamada added. "The results are expected to accelerate the development of advanced biomaterials to control local inflammation or microdevices that simulate the microenvironment of inflammatory conditions."

The study, titled “Substrate stiffness controls proinflammatory responses in human gingival fibroblasts”, was published in Scientific Reports.

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