Evidence summarized in a May 15, 2026 report indicates that apical periodontitis—an infection around the tip of a tooth root that can be painless and go unnoticed—may contribute to low-grade systemic inflammation and be associated with worse blood sugar regulation. In observational research cited in the report, people treated with root canal therapy for these infections showed improved long-term blood sugar measures and lower inflammatory markers during follow-up, though researchers caution that causation has not been proven.
Researchers describe apical periodontitis as a deep infection and inflammatory condition located around the end of a tooth root, typically caused by microbes in an infected root canal.
Because it can cause little or no pain, the condition is often detected only when a dentist finds changes on dental X-rays, according to the report.
The article points to studies in which people who received root canal treatment for chronic infections at the tooth-root tip subsequently showed improvements in measures of blood sugar control along with reductions in inflammatory markers over as long as two years of follow-up. The report also describes a proposed mechanism: persistent dental infection may help sustain low-grade inflammation, which could interfere with insulin’s action and make blood sugar harder to regulate.
Researchers emphasized that these findings do not establish root canal therapy as a treatment for diabetes, and that more controlled research is needed to determine whether treating apical periodontitis directly improves metabolic outcomes.
