An inflammatory process in the gingival and/or periodontal tissues prior to implantation seems to be a significant risk factor contributing to impaired osteointegration with implant rejection in the early or late stages due to the development of periimplantation mucositis followed by periimplantitis. In this regard, the task of searching for highly informative markers, both morphological and laboratory, as well as molecular genetic markers, remains extremely relevant, allowing predicting the risk of developing periimplantitis in various populations. An equally urgent task is the search for effective means of adjuvant therapy and prevention of inflammatory complications after dental implantation. The aim of this study was a comprehensive histopathological assessment of the state of the gingiva by biopsy at the stage before implantation in a clinical case series.
 In a clinical case series (25 patients), using a descriptive histological method, a histopathological analysis of gingival biopsy samples obtained at the stage of implant placement was performed. The data of the descriptive histological analysis were supplemented by the results of an immunohistochemical study for the expression of vitamin D receptors (VDR) in the gingival tissues and inflammatory infiltration cells.
 According to the results of a descriptive histopathological analysis, in 7 out of 25 cases (28%) in the gingival tissues of the edentulous area of the jaw in the area of the included defect of the dentition, the phenomenon of less or more pronounced chronic inflammation was revealed, manifested in lymphocytic or mixed lymphohistiocytic infiltration. Other significant histopathological changes were presented by the changes in the gingival epithelium, as well as disorders in the vessels of the microvasculature. Immunohistochemical analysis demonstrated the presence of a strong nuclear and/or cytoplasmic expression of VDR both in the epithelium and cells of the inflammatory infiltrate, regardless of the age and gender of the patients or the severity of inflammatory changes in the gingival tissues.
 The results of the pilot analysis of clinical case series are of interest for further study of pre-implantation gingival or periodontal lesions, and may help identify biomarkers of the subsequent development of periimplantitis, as well also provide a fundamental rationale for the use of vitamin D as a prophylactic or therapeutic adjuvant.