Dentists remove tooth decay, fill cavities, and repair fractured teeth. Dentists diagnose and treat problems with patients' teeth, gums, and related parts of the mouth. They provide advice and instruction on taking care of the teeth and gums and on diet choices that affect oral health. They clean teeth, fill cavities, perform surgeries, and promote oral health. What are the duties and responsibilities of a dentist? Dentists examine patients, diagnose dental problems, clean teeth, perform procedures like fillings and extractions, design and fit dental prosthetics, and educate patients on oral hygiene.