As a dentist, it is fairly common to meet patients who suffer from systemic medical conditions or diseases that can impact oral health and dental treatment. Possessing background knowledge of the systemic-oral health relationship must be emphasized to have a safe and successful treatment course for both the dentist and the patient. Dentists need to learn the fundamental pathomechanisms of common diseases and what oral manifestations may appear according to the underlying systemic diseases. Also, what kind of medications to use and their general brand names for treating the corresponding illnesses. There will be times when patients don’t really understand how their systemic medical conditions or the corresponding drugs impact the dental operation, so dentists must correctly inform them of the significance.