Mutated genes lead to tooth decay

Some people brush their teeth more assiduously than others – but does it make any difference? Keystone

Why do some thorough tooth-brushers develop caries – tooth decay – while other people who take a more relaxed attitude to dental hygiene don’t have any holes? Researchers from the University of Zurich have for the first time pinpointed a gene complex responsible for the formation of tooth enamel.

Two teams from the Centre of Dental MedicineExternal link and the Institute of Molecular Life SciencesExternal link used mice with varying mutations of the enamel proteins involved in the so-called Wnt signalling pathway.

“All mice with mutations in these proteins exhibit teeth with enamel defects,” said Pierfrancesco Pagella, one of the study’s two first authors. “Therefore, we demonstrated that there is a direct link between mutations in the genetic blueprints for these proteins and the development of tooth enamel defects.”

This genetic discovery, published this week in the journal Science SignalingExternal link, goes a long way towards improving scientists’ understanding of the production of tooth enamel.

Tooth’s resistance

The team of researchers was the first in the world to use modern genetic, molecular and biochemical methods to study tooth enamel defects in detail.

“We discovered that three particular proteins involved in the Wnt signalling pathway aren’t just involved in the development of severe illnesses, but also in the qualitative refinement of highly developed tissue,” said co-first author Claudio Cantù from the molecular biologist research group.

“If the signal transmission isn’t working properly, the structure of the tooth enamel can change.”

The hardness and composition of the tooth enamel can affect the progression of caries.

“We revealed that tooth decay isn’t just linked to bacteria, but also the tooth’s resistance,” added Thimios Mitsiadis, professor of oral biology at the Center of Dental Medicine.

New products

Bacteria and their toxic products can easily penetrate enamel with a less stable structure, which leads to carious lesions, even if oral hygiene is maintained.

Understanding the molecular-biological connections of tooth enamel development and the impact of mutations that lead to enamel defects opens up new possibilities for the prevention of caries.

“New products that hinder the progress of tooth caries in the event of defective tooth enamel will enable us to improve the dental health of patients considerably,” Mitsiadis said.