Dental News - Novel discovery may help in early caries detection in high-risk children

Dental Tribune International

Fri. 6. October 2017

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UMEÅ, Sweden: Researchers at Umeå University in Sweden have made a novel discovery connecting highly virulent types of the Streptococcus mutans caries bacterium and their adhesive function to children with rampant caries and increased risk of dental caries. According to the researchers, the results could lead to a better way of identifying high-risk patients and improving treatment.

For the five-year study, the saliva of 390 children who were 12 years old at the start was analysed and their dental health monitored. After analysis of the saliva samples and isolated bacterial strains, the children were divided into various risk groupings based on the genetic type of the caries bacterium they carried. At the five-year follow-up, the researchers could see how caries had developed in the various risk groupings.

Through biochemical studies, the researchers found a link between the adhesive proteins SpaP B and Cnm and their adhesion to saliva and DMBT1, a protein in the saliva. They also showed that higher binding ability led to increased caries development over the five-year study period. Based on the findings, the researchers established that high-risk children have more virulent variants of S. mutans, whose adhesive function makes them more aggressive and better survivors.

“Caries is a life style condition often caused by eating and oral hygiene habits that lead to an acidic pH in the mouth. The pH level has a damaging effect on the enamel and further promotes the growth of acid producing bacteria such as Streptococcus mutans,” said Prof. Nicklas Strömberg, head of the Department of Cariology at the university and lead author of the study.

“This new knowledge of the identified types of bacteria and how they initiate caries development could be used to improve individualised dental care. The presence of the bacteria could be used as biomarkers for early detection of high-risk patients. Also, their adhesive function could constitute new targets for treatment,” said Strömberg.

According to Strömberg, in a study yet to be published, his team found that other high-risk children have genetic defects in their salivary receptors for bacteria, and the affected genes may involve those associated with autoimmune diseases. Nevertheless, he stated: “It’s still important to emphasise that caries in the many individuals of low-to-moderate risk is still modulated by eating and oral hygiene habits.”

The study, titled “Streptococcus mutans adhesin biotypes that match and predict individual caries development”, was published in the EBioMedicine journal on 21 September.