Most dental procedures are minor and do not require you to fast or change your insulin regimen. Typically, you can have a procedure done within two hours of breakfast and your morning insulin injection. Minor dental procedures include cleanings, fillings, root canals, crowns, etc. More involved procedures that require an oral surgeon may require adjustments to your insulin regimen. This should be discussed in detail with your oral surgeon. Only change your insulin regimen with advice of your doctor or dentist.