In my many years in the dental field I am often asked, "Why does the dentist need to know my medical history and all my medications? I'm only here for a checkup."
Many diseases and medications have significant effect on your mouth and teeth. For instance Diabetes can increase the risk of periodontal disease. Certain medications can cause dry mouth which in turn can increase the risk of cavities. Some medications may require the use of a different type of anesthetic.
Dentists will make sure that any prescriptions given will not interfere with medications a patient is currently taking. It is best to keep your dental office updated with any surgeries, allergies, health changes or prescription changes. Depending on your health status at the time of your visit different treatment alternatives or even delaying treatment, may be recommended. One of the hygienists in our office said it best, "your head is attached to your body and it all works together." Amusing but true.