The NSPT, which consisted of subgingival debridement - scaling and root planning (SRP) under local anesthesia. On average, the treatment of the entire oral cavity was completed within four sessions (sessions of 50 minutes). The SRP was performed by one experienced periodontist (KRVV) using Gracey curettes (Hu-Friedy MFG. Co. Inc., Chicago, IL, USA), ultra-sonic devices (Bob-Cat, Dentsply/Cavitron, Long Island City, NY, USA) and, if necessary, with multilaminated drills.