Oral, periodontal, and peri-implant soft tissues present particular characteristics that clearly differentiate them from other tissues in the body. Non-surgical and surgical treatment of periodontal and peri-implant diseases generate different wound types in which a repair process is activated. The stages of wound healing proceed in an organized way, following four phases: hemostasis, inflammation, proliferation, and tissue remodelling, which are the same in all tissues. However, oral soft tissues present special features such as rapid wound closure and reduced scar formation. In order to understand the wound repair behaviour of the different soft tissues, it is essential to deepen our knowledge of tissues characteristics in health and disease.

As the normal wound repair process is critical for successful non-surgical and surgical outcomes, and considering that soft tissues are the first barrier in this process, a better understanding of the intrinsic features of different soft tissues in health, disease, and during the healing process seems to be of paramount importance. The widespread occurrence of periodontal and peri-implant diseases and the awareness that lost tissues can be both repaired and regenerated determined considerable interest on factors and cells that mediate the healing process. In the last few years, various streams of research have been developed in this field, from a biomolecular point of view –through gene profiling and protein expression analysis – and also exploring the possible applications of different biomaterials/biomodulators as adjunctive non-surgical and surgical therapy with the aim of improving the wound microenvironment.

Therefore, the aim of this Special Issue is to update the current knowledge and understanding of the oral, periodontal, and peri-implant soft tissues features at clinical, cellular, and molecular levels, in health, disease, and during the repair processes. For this Special Issue, we especially welcome basic science, original clinical research, or review articles that provide relevant information, describe important novel results, and highlight the current state of oral soft tissues features in health, disease, and during wound healing. The abovementioned issues would in turn open the discussion to the development of novel approaches to improve soft tissues healing in general.

Potential topics include but are not limited to the following:

• Cross-talk between connective tissue cells (mainly fibroblast/myofibroblast), inflammatory cells, protein expression, and clinical behaviour of the different oral, periodontal, and peri-implant soft tissues
• In vitro and in vivo human studies evaluating extracellular matrix components (mainly hyaluronan), cellular response and interactions, growth factors, integrins, cytokines, differentially expressed genes, and protein expression in the different oral soft tissues in health, disease, and repair process
• Recent advances in gene expression profiling and proteomic analysis to deepen and understand the different tissue response after non-surgical and surgical periodontal and peri-implant treatment
• Analysis of individual cells of each of the different oral soft tissues related to the repair process to understand their biological potential in the healing process
• Development of adjunctive approaches for non-surgical and surgical treatment of periodontal and peri-implant disease in order to optimize the wound microenvironment
• Novel developments in surgical approaches, which incorporate biomaterials/bio modulators as an adjunctive treatment
• Currents concepts in the treatment of scar formation in the oral wound healing
• New insights of gene therapy and improvement in oral soft tissues injury repair using small and large animal models
• Periodontal and peri-implant soft tissue regeneration and repair using gene therapy-based strategies in clinical trials