Study aim: The aim of the present study was to evaluate the effectiveness of Propolis gel under Coe-Pack on gingival on Gingival Healing Indices after periodontal flap surgery. Design: Clinical trials have a control group, two-way blind, easily randomized, phase 3 on 18 patients. The flip coin method was used to randomize each side of the mouth Settings and conduct: In the specialized department of the Faculty of Dentistry, University of Isfahan. Selection of 20 patients by easy sampling method. Everyone is blind except the clinical caregiver. Select the patient's first position using the flip coin method and place in group A. also, gel and placebo have A and B labels Participants/Inclusion and exclusion criteria: Entry requirements: Patients with moderate to severe chronic Periodontitis require two side or whole mouth periodontal flap surgery that is systemically healthy The same type of flap on both sides in each person Age over 18 years Pelaque index Less than or equal to 1 after health education No contraindications for surgery No need for prophylactic Antibiotics Do not take Corticosteroids or Hormones for the past two months Having acceptable cooperation Conditions of non-entry: Smoking Pregnancy Taking anti-inflammatory drugs or Antibiotics Existence of systemic disease Pelaque index 2 or 3 after health education Need to cut more than 2 mm of bone Lack of cooperation and patient satisfaction Intervention groups: Treatment group: after surgery, use 20% propolis gel, which is made by Propolis Manufacturing Company (Green Plants of Life Company) under the Coe Pack dressing(GC America Inc), and then mix the Coe Pack thoroughly and apply it on the surgery site Control group: after periodontal flap surgery, we place the placebo gel and then put the Coe Pack dressing( GC America inc) on the desired place Main outcome variables: Pain index, plaque index, papillary bleeding index, healing index