The patient was diagnosed with type 1 diabetes mellitus at the age of 15. Medical management of her diabetes is with a multiple-dose insulin regimen, consisting of insulin glargine 16 units hs (long-acting insulin, see Table 1) and insulin aspart (rapid-acting insulin, Table 1) before meals. The dose of insulin aspart is calculated based on the carbohydrate content of the planned meal and the blood glucose level as determined by a fingerstick test. Her most recent hemoglobin A1c (HbA1c) was 6.8%, indicating excellent metabolic control. She has no history of severe hypoglycemic events. She takes no other medications.

Dental history and history of the current problem

Tooth #4 was extracted more than 10 years ago. The tooth was replaced with a fixed partial denture extending from #3 to #5. The patient visited her dentist intermittently, and received dental cleanings. She occasionally required amalgam and composite restorations, but noticed the fixed partial denture appeared loose approximately two months ago. Upon clinical evaluation, it was determined that the cement seal had been lost, and caries was present on the remaining tooth structure of the abutment teeth. In order to fabricate a new fixed restoration, periodontal surgery is necessary to expose sound tooth structure on the abutment teeth (crown lengthening procedure). The patient is scheduled for periodontal surgery in the morning and will not eat (NPO) after midnight in preparation for surgery. The dentist is concerned that she may become hypoglycemic before or during the procedure and contacts her endocrinologist for guidance.