What HbA1c level indicates poorly controlled diabetes in a patient?

HbA1c (glycated hemoglobin) reflects average blood glucose levels over the preceding 2-3 months. Normal: below 5.7%. Prediabetes: 5.7-6.4%. Controlled diabetes (ADA goal): below 7.0%. Uncontrolled/poorly controlled diabetes: 8.0% or higher. An HbA1c of 8.0% or greater indicates that blood glucose has been consistently elevated and increases the risk of diabetic complications. In the dental context, patients with HbA1c above 7-8% have increased risk of periodontitis, poor wound healing, and infection. Elective dental procedures may be deferred in patients with significantly uncontrolled diabetes (HbA1c above 9-10%).