Among various systemic diseases, diabetes, in particular, is associated with a high prevalence of periodontal disease. The patient was a 68-year-old woman who first visited our clinic in November 2012 with the chief complaints of tooth mobility, gingival swelling and chewing disorder. She had been diagnosed as having type-2 diabetes and was receiving lifestyle guidance and regular examinations/blood tests every 3 months, but no medications. According to the latest blood test results, the HbA1c value was 7.2%. The patient had no history of smoking. In this report, we describe that as a result of periodontal treatment, the patient's periodontitis as well as HbA1c improved. We shall report cases that have been progressing smoothly after SPT transition.