At the initial visit, a clinical examination will be performed on each patient and clinical parameters such as plaque index, gingival index, pocket depth and clinical attachment level will be recorded. At baseline all the patients will receive phase I therapy which includes Supragingival scaling and thorough oral hygiene instructions. Patients will be recalled after one week for Subgingival plaque sample collection. One week after scaling and root planning, baseline subgingival plaque sample will be collected using sterile curettes. The collected sample will be immediately transferred to a transport medium and sent to laboratory for microbiological analysis of Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa) by using multiplex PCR.

   In Group A subgingival scaling and root planing will be done and satranidazole gel is placed. In Group B after subgingival scaling and root planing hyaluronic acid gel will be injected into the pocket until the material is detected at the gingival margin. Then periodontal dressing (coe-pak) will be placed on treated site to ensure that gel will stay long enough to be effective in the pocket. After one-week periodontal dressing is removed.

   Clinical parameters will be recorded after 1 month and 3 months after treatment and post operative subgingival plaque samples will be collected from two groups and sent for microbiological analysis after 3 months.