While plant-based foods are an essential part of a healthy diet, an international team of researchers has found that microscopic plant stones, known as phytoliths, could contribute to dental wear over time, potentially leading to more frequent visits to the dentist.
They designed artificial leaves embedded with these microscopic particles and mounted them on a device that simulates the pressure and sliding motion of chewing against dental enamel samples provided by the local scientists.
According to experimental results published in the Journal of the Royal Society Interface, even soft plant tissues caused permanent enamel damage and mineral loss upon interaction with enamel.
A home-made experimental device was developed for simulating chewing processes between the synthetic leaf and the dental sample.
Phytoliths are microscopic, silica particles that form within the tissues of many plants when the roots take up soluble silica from the soil and the vascular system deposits it in other parts of the body.
The scientists designed artificial leaves made from a polydimethylsiloxane (PDMS)-based matrix with embedded opaline phytoliths obtained from wheat stems and leaves.
The resulting leaf, with a thickness and stiffness similar to that of a real leaf, was then fixed to a holder and brought into controlled, repeated contact with healthy human wisdom teeth samples collected from dentists, to simulate the sliding and pressure of chewing.
The physical and chemical changes in the leaf and the dental enamel were analysed using high-resolution microscopy and spectroscopic techniques.
The team found that even though the phytoliths themselves break down after repeated contact, they still worsen existing wear on tooth enamel and reduce its mineral content.
A surprising outcome was the main mechanism of wear, which turned out to be a quasi-plastic or permanent deformation arising from weakness in the enamel’s microscopic structure, and not classic brittle fracture.
