A total of 24 type 2 DM patients with periodontitis will be selected for the study, and randomly divided into two equal groups,who are at least 35 years of age and 16 teeth and type II diabetes are (at least the last 3 months of diagnosis of diabetes and its FBS More than 110 have), and also with periodontal disease are chronic moderate (at least in three areas Attachment level to a depth of 3-4 mm maxillary or mandibular been confirmed by clinical examination and radiographic signs are being); Takes place. The initial HbA1c Patients should be between 7-9 percent over the past three months has changed his medication also found the necessary explanations on how to do that consent, Plaque index (PI) by Loe & Silness, bleeding on probing (BOP) based on Carter and Barnes (if any bleeding number 1 and its absence is 0), probing depth (PD) and clinical attachment levels (CAL) were recorded. "Group 1": (12 patients) was treated with oral hygiene instruction, scaling and root planing, and doxycycline gel for 15 days; and "Group 2": (12 patients) has the same treatment but with placebo gel, After 12 weeks their periodontal condition and Fasting blood sugar (FBS), glycated hemoglobin (HbA1c) level, will be reevaluated.