Enamel caries in young adults: most early lesions do not progress

A new study from the Fit Futures cohort has followed almost 600 Norwegians from age 17 to age 27, mapping how early caries lesions in the enamel develop through the transition from adolescence to adulthood.

The study shows that enamel caries is highly prevalent among young people, but that more than 80% of lesions either arrest or reverse over a ten-year period without any need for operative treatment.

What is this about?

Enamel caries is the earliest visible stage of tooth decay, and can either progress further into the dentin or regress if conditions in the mouth change. Many caries registries only count cavities that have reached the dentin, so little is known about what happens to early enamel lesions over time.

Researchers followed 584 participants from the Fit Futures study in Tromsø and Balsfjord, first as 17-year-olds in 2010-2011 and again as 27-year-olds in 2021-2022, using clinical dental examinations with radiographs and photographs at both time points. The study was carried out in collaboration with several research institutions, with Professor & Senior Scientist Aida Mulic from NIOM contributing as a co-author.

What did the researchers find out?

Almost all participants had enamel caries both as 17-year-olds (99.8%) and as 27-year-olds (95.5%), yet the average number of affected surfaces still declined over the period. Of the lesions present at age 17, 18% had progressed into dentin caries ten years later, most often on proximal surfaces and upper-jaw premolars.

The risk of more numerous and active lesions was higher among participants who were female, had lower socioeconomic status, reported poorer general health, brushed less often, and drank soft drinks frequently - the most consistent dietary risk factor, with a clear dose-response relationship.

What are the key results?

Enamel caries is nearly universal in this age group, and the transition to adulthood remains a period of substantial caries activity. Still, the vast majority of lesions do not progress into cavities requiring restorative treatment, supporting non-operative management - improved hygiene, dietary guidance and fluoride - over drilling as the first choice.

The researchers highlight that extra attention should go to young people with low socioeconomic status and poorer general health, both identified as key risk factors for progression.