In a paper entitled Social inequalities in childhood dental caries: The convergent roles of stress, bacteria and disadvantage, researchers from the University of British Columbia in Canada found that “a convergence of psychosocial, infectious and stress-related biological processes appears to be implicated in the production of greater cariogenic bacterial growth and in the conferral of an increased physical vulnerability of the developing dentition.”
In two 2004-2006 studies of 132 kindergarten children from varying socioeconomic backgrounds in the San Francisco Bay Area of California, they performed detailed dental examinations to count decayed, missing or filled dental surfaces and microtomography to assess the thickness and density of microanatomic dental compartments in exfoliated, deciduous teeth.
Decay was linked with three factors: high levels of decay-causing bacteria; high levels of a hormone called cortisol; and a family income below poverty level.
Children with the most decay had high levels of decay-causing bacteria in their mouths. They also had high levels of cortisol in their saliva. Cortisol is released in response to stress. It aids in the body’s digesting of sugars.
“We hypothesized that family stressors and stress-related changes in oral biology might explain, fully or in part, the known socioeconomic disparities in dental health,” the authors wrote. “We found that nearly half of the five-year-old children studied had dental caries. Low SES, higher basal salivary cortisol secretion, and larger numbers of cariogenic bacteria were each significantly and independently associated with caries, and higher salivary cortisol reactivity was associated with thinner, softer enamel surfaces in exfoliated teeth.”
They concluded: “The socioeconomic partitioning of childhood dental caries may thus involve social and psychobiological pathways through which lower SES is associated with higher numbers of cariogenic bacteria and higher levels of stress-associated salivary cortisol.