New technique helps researchers understand how acid damages teeth

The Universities of Birmingham and Surrey have developed a new technique to improve understanding of how acid damages teeth.

The scientists’ research focused on analysing the impact of acid on dentine, a hard tissue which forms the main bulk of human teeth and supports the enamel which covers the surface helping to make teeth strong and resilient.

In the laboratory, the researchers performed a technique in which electrons were accelerated to near light speed to generate bright X-rays that were used to scan dentine samples while they were being treated with acid. This enabled the team to build clear 3D images of dentine’s internal structure with sub-micrometre resolution (a micrometre being one-thousandth of a millimetre). The team analysed the changes to the dentine structure over a period of six hours, allowing them to create the first-ever time-resolved 3D study (often referred to as 4D studies) of the dentine microstructural changes caused by acid.

The study, published in journal Dental Materials, highlights that acid dissolves the minerals in different structures of dentine at different rates.

Dr Richard Shelton , of the University of Birmingham’s School of Dentistry, said: "Dental erosion is a common oral condition caused by chronic exposure to acids. Repeated acid exposure can lead to the irreversible loss of dental hard tissues. Dentine can become exposed to acid following severe enamel erosion, crown fracture, or gum recession which can cause hypersensitivity and other oral health problems, it’s therefore imperative that we improve our understanding of how acid damages teeth."

Professor Gabriel Landini , also of the University of Birmingham, added: "We hope that our research will lead to improvements in treatments that can restore the structural integrity and aesthetics of teeth that have been damaged by acid."

Dr Tan Sui , Senior Lecturer in Materials Engineering at the University of Surrey, who led the research group, said: "Relatively little is known about how exactly acid damages the dentine inside our teeth at a microstructural level. This new research technique changes that."

Nathanael Leung, a final year PhD candidate at the University of Surrey, has been awarded a GSK Award 2021 by the Oral and Dental Research Trust. He will continue to study the mechanical response of dentine to masticatory forces in correlation with the microstructural changes that acid causes as well as in response to different treatments like fillings and crowns.