When Tristen Boyer recently had a couple of cavities filled, her dentist suggested she get fluoride treatment afterward. She has Crohn’s disease, which puts her at increased risk for tooth decay.

Alexander Daniel, DDS, left, demonstrates fluoride treatment on resident Cameron Onken, right, at the Johns Hopkins Outpatient Center, Friday, Feb. 28, 2025, in Baltimore. (AP Photo/Nick Wass) ...