 - completed initial periodontal treatment consisting of oral hygiene instruction, scaling and root planing under local anesthesia according the concept of full-mouth disinfection and re evaluation of the tissue response and the patients plaque control 3 months later. Sites with infrabony defects and persisting pockets PD 5 mm and bleeding on probing, BOP that occur at re evaluation or supportive periodontal treatment SPT are subjected to surgical therapy. 