Periodontal disease is today one of the main causes of tooth loss. Pathogenic microorganisms and microbiological biofilm are the primary culprits of these diseases, and their elimination is the key goal of periodontal disease therapy. Through therapy, the aim is to create a biocompatible tooth root surface and ensure that the immune system once again controls the microorganisms within the oral cavity. Residual periodontal pockets, pockets that are present after initial periodontal therapy, represent a challenge in periodontal treatment, and their presence is associated with an increased risk for the progression of periodontitis. Non-surgical therapy of residual pockets includes a mechanical and chemotherapeutic approach to treatment. The mechanical approach consists of supragingival plaque removal and subgingival scaling and root polishing. When signs of active disease persist after mechanical therapy, it may indicate the presence of deeper, less accessible layers of bacterial plaque or the presence of more aggressive bacterial strains. In such cases, additional pharmacotherapeutic measures are often recommended. Agents, such as antiseptics and antibiotics, are used as mechanical cleaning adjuncts. There are numerous antimicrobial preparations for subgingival application that are used as aids in the fight against periodontopathogenic microorganisms, especially in areas that cannot be fully mechanically removed. Increasingly, additional non-surgical methods such as laser application, antimicrobial photodynamic therapy, and air polishing instruments are being used. Although non-surgical periodontal therapy is considered ideal for the initial treatment of periodontitis, it is noted that a significant percentage of residual pockets remain after non-surgical periodontal therapy. For most patients, residual pockets will have to be treated either through surgical procedures or by adjusting the intervals of supportive therapy visits and using adjuvant therapeutic agents according to specific patient needs.