Mesenchymal stem cells (MSCs) have the ability to differentiate into osteoblasts, chondroblasts, adipocytes, and even myoblasts. Most studies have focused on finding MSCs in different parts of the body for medical treatment. Every joint structure, including bone, joint fat, articular cartilage, and synovium, potentially contains resident MSCs. Recently, a progenitor cell population has been found in synovial fluid and showed similarities with both bone marrow and synovial membrane MSCs. Synovial fluid MSCs have been studied in healthy persons and osteoarthritic patients in order to explore its potential for treatment of some orthopedic disorders. Here, we briefly review the current knowledge on synovial fluid MSCs, their origin, relation to some orthopedic diseases, and future applications.

Purpose: The aim of this study was to evaluate the presence of periodontopathogens in subgingival periimplant sites in partially edentulous patients using polymerase chain reaction procedures, with regard to areas with clinical and radiographic signs of health and areas presenting periimplant disease. Materials and Methods: Thirty nonsmoking, partially edentulous patients, aged 30 to 76 years, were included in this study and divided in 3 groups according their clinical and radiographic characteristics. Group A (n = 10) presented periimplant health, group B (n = 10) presented periimplant mucositis, and group C (n = 10) were patients with periimplantitis. Periimplant tissues were clinically examined as regards the color of mucosae, presence of bacterial plaque, depth and bleeding on probing, and local suppuration. History of periodontal disease was also considered. Radiographic analysis evaluated the presence of bone loss around the implant. Samples of periimplant crevicular fluid were collected to analyze the presence of periodontal pathogens, Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythensis (Tf), and Treponema denticola (Td). Results: The results showed that the history of periodontal disease is associated with periimplant disease. The bacteria Aa, Pg, Pi, Td, and Tf were present in periimplant sites clinically and radiographically characterized, as healthy periimplant tissues, mucositis, and periimplantitis. Conclusions: We concluded that Aa, Pg, Pi, Td, and Tf are present in healthy and diseased conditions. Therefore, these periodontal pathogens are not strictly related to periimplant disease sites.

To analyze the interleukin (IL)-1β and IL-10 expressions in periimplant crevicular fluid (PICF) in healthy and diseased regions to elucidate the inflammatory process around implants and its influence on clinical diagnosis. PICF samples from 30 patients were analyzed for IL-1β and IL-10 concentrations by enzyme-linked immunosorbent assay. Patients were divided in Groups A (health), B (mucositis), and C (periimplantitis). Plaque accumulation, periodontal phenotype (PP), depth on probing, and history of periodontitis (HP) were evaluated. IL-1β levels were lower in healthy group compared with Groups B (P < 0.0005) and C (P < 0.001). IL-10 levels were higher in Groups A compared with B (P = 0.033) and C (P = 0.0001). Patients with HP and thin PP had 9 and 4.5 times more chance of presenting disease, respectively. Lower IL-1β and higher IL-10 levels characterized healthy periimplant conditions, which demonstrate the anti-inflammatory predominance in sites without disease signs. IL-10 levels decrease significantly according to increase of disease status. Therefore, its levels can differentiate healthy, mucositis, and periimplantitis. Thin PP and HP are associated with periimplant disease. These findings suggest the use of ILs as a biochemical marker for early diagnosis of periimplant disease.

This case report presents an analysis of the clinical, radiographic, and histological features of a peri-implant lesion around an implant placed immediately after extraction of a tooth with a periapical lesion. A 52-year-old man received an immediate implant (3.75 x 11.5 mm2) placed in the anterior region of the maxilla. Three years after implant placement, the patient presented with swelling in the anterior portion of the maxilla. Radiographic examination showed a well-circumscribed radiolucency around the implant. The implant and the lesion were removed and fixed in 10% buffered formalin and processed. Histological analysis showed 3 types of epithelium: respiratory, cuboidal, and non-keratinized stratified squamous. In the cyst wall peripheral nerves, arteries, veins, and chronic inflammation were present. The diagnosis was nasopalatine duct cyst. We concluded that the nasopalatine duct cyst can develop in association with dental implants. Clinically, the lesion is similar to the classical nasopalatine duct cyst. Histological analysis should be mandatory in all cases of peri-implant lesions and in all dental periapical lesions before immediate implant placement.