Bacteria Persist After Treatment for Severe Early Childhood Caries

Bacteria Persist After Treatment for Severe Early Childhood Caries

Researchers at Oregon Health & Science University (OHSU) School of Dentistry in Portland recently took another look at a cohort of children with early childhood caries in order to determine current bacteria levels in subjects they had studied a year earlier. The children from the original study had received complete dental rehabilitation, including restorative care, sealant placement, and fluoride varnish application. At 1-year post-treatment, the researchers collected plaque samples from the five subjects who were available for all of the post-rehabilitation recare visits. They found 37 genotypic strains of Streptococcus mutans, two genotypic strains of S. sobrinus, and seven non-mutans streptococci (MS) strains during the entire study—including six new MS strains detected at the 1-year follow-up. Some of the strains exhibited resistance to xylitol, a sugar polyol with cariostatic properties.

“In the follow-up study, we identified caries-active children who possess MS genetic strains with different xylitol-resistance properties, with some strains exhibiting increased cariogenic potential,” notes Curt Machida, PhD, principal investigator and OHSU professor of integrative biosciences and pediatric dentistry. The researchers hope that a better understanding of the virulence of caries-causing bacteria strains—as well as their reaction to xylitol and other caries-fighting therapies—will help improve strategies for caries prevention and management. The second study was published online in the December issue of the Journal of Oral Microbiology.