How to Treat and Prevent Canker Sores features Tom Rogers (MD) sharing what actually helps these painful mouth ulcers—and what often worsens them. He covers common triggers like stress, food sensitivities, and fluoride toothpaste, and explains why immune support with B vitamins, zinc, selenium, and lysine can make a difference. Rogers also discusses helpful remedies like DGL and zinc lozenges, offering simple, practical ways to reduce recurrence and support both oral and digestive health from the root.