I hope you all had a restful long weekend. I’m sharing a recent study I found thought-provoking:
Association between sleep duration and dental caries in a nationally representative U.S. population (July 2023)
This paper supports the idea that sleep plays a central role in many modern health problems.
The researchers observed that people who sleep fewer than seven hours per night tend to have more dental cavities.
Poor sleep has many adverse effects, but it’s not often linked directly to dental decay. We also seldom think of cavities as a metabolic disease, yet there is a metabolic and immune component to how decay develops and progresses.
What might explain the connection between short sleep and more cavities? One possibility is disruption of hormones that regulate appetite and metabolism, which affects dietary patterns and oral environment. Another study found higher body mass index to be associated with increased levels of Streptococcus mutans, a major cariogenic bacterium. Reduced sleep may also decrease salivary flow—an important natural defense against decay—though factors such as mouth breathing were not always addressed in these analyses.
Circadian misalignment, such as that experienced by shift workers, is linked to higher fasting blood glucose and has been correlated with increased decayed, missing, or filled teeth (DMFT). A disrupted circadian rhythm can also impair immune function; because the oral microbiome is regulated in part by host immune responses, circadian disruption may indirectly promote an environment more favorable to cavities.
If you regularly get fewer than seven hours of sleep—whether you’re a parent up with children, a shift worker, or someone with chronic sleep disruption—there are simple interventions that may help. For example, for people who breathe through their mouths at night, addressing nasal breathing can improve sleep quality and oral health.
The study also reported that people with high DMFT scores (more than ten affected teeth) had notably lower salivary melatonin levels. Melatonin isn’t only involved in sleep regulation; it has antioxidant properties and can counter oxidative stress involved in the onset and progression of dental caries.
In practical terms, low melatonin may leave oral tissues more vulnerable to damage. Melatonin functions as part of the body’s defensive toolkit, helping to mitigate oxidative and inflammatory processes.
This is another reason to work with a clinician who considers the whole person. Functional dentists, for example, are often trained to evaluate how sleep, facial development, and breathing patterns influence oral health and risk for decay. They can integrate these factors into prevention and treatment plans in ways that typical medical visits may not address.
Dental professionals: if you are treating cavities without discussing sleep and breathing with your patients, you may be missing an important root cause.
For patients and clinicians alike, this study adds another reason to prioritize sleep as a modifiable risk factor for the world’s most common disease: dental caries.
Have a great week,
P.S. I also have a short list of five things I never go to bed without.