Project description:The mucosal penetration area formed by implant placement is critical problems of dental implant treatment, because epithelial barrier is broken and it can become a source of inflammation. To clarify the influence and risk caused by dental implant treatment in peri-implant soft tissue, we compared to gene expression profile of peri-implant soft tissue and oral mucosal tissue with microarray analysis. Both side upper first molars of 4 week-old rat were extracted, and titanium alloy implants were placed only in the left extraction socket. Four weeks after surgery, samples were harvested from left side of peri-implant soft tissue and right side of oral mucosal tissue.
Project description:The mucosal penetration area formed by implant placement is critical problems of dental implant treatment, because epithelial barrier is broken and it can become a source of inflammation. To clarify the influence and risk caused by dental implant treatment in peri-implant soft tissue, we compared to gene expression profile of peri-implant soft tissue and oral mucosal tissue with microarray analysis.
Project description:Peri-implant fibrosis is one of the most common reasons for implant failure and surgical revision after prosthetic joint replacement. This type of surgical revisionis associated with substantial additional morbidity and healthcare costs. However, the cellular and molecular mediators of peri-implant fibrosis remain unclear. Here, we show that peri-implant fibrotic tissue in mice and humans is largely composed of a specific population of leptin receptor-expressing(LEPR+) cells and that these LEPR+cells are necessary and sufficient to both generate and maintain peri-implant fibrotic tissue. Genetic ablation of LEPR+cells prevents peri-implant fibrosis, and implantation of LEPR+cells from peri-implant fibrotic tissue is sufficient to induce fibrosis in secondary hosts. We further identify adhesion G protein-coupled receptorF5 (ADGRF5) as a crucial mediator of the fibrotic response by LEPR+cells, as conditional deletion of ADGRF5 in LEPR+cells attenuates peri-implant fibrosis while augmenting peri-implant bone formation. Finally, we demonstrate that inhibition of ADGRF5 by intra articular or systemic administration of neutralizing anti-ADGRF5prevents and reverses peri-implant fibrosis. Thus, pharmaceutical agents that inhibit the ADGRF5 pathway inLEPR+cells may represent a new approach to prevent and treat peri-implant fibrosis.
Project description:In this study we want to ascertain the differences and similarities of infected and inflammated peri implant tissue versus healthy peri implant tissue at the mRNA level.
Project description:Oral health is associated with a symbiotic microbial community and host-microbe homeostasis is maintained by the controlled immune response. Various factors can disrupt this homeostasis. Dysbiosis, which is characterized by increased immune response and a shift in the microbiome, contributes the pathogenesis of peri-implantitis. Peri-implant mucosa and commensal bacteria play important roles in the maintenance of host-microbe homeostasis, but little is known about how they interact. We have therefore investigated the early host-microbe interaction between a commensal multispecies biofilm (Streptococcus oralis, Actinomyces naeslundii, Veillonella dispar, Porphyromonas gingivalis) and peri-implant mucosa at 24 and 48 h. Our in vitro peri-implant mucosa-biofilm model contained organotypic oral mucosa, implant material and biofilm. After 24 h, the biofilm induced a modest innate immune response in the peri-implant mucosa by the upregulation of 5 genes related to immune and inflammatory response and the increased secretion of IL-6 and CCL20. This controlled immune response protected tissue integrity and the peri-implant mucosa remained intact. The secreted antibacterial proteins human β-Defensins-1, -2, and CCL20 controlled the overgrowth of the biofilm by reducing its volume - without affecting the live/dead ratio or bacterial distribution. Thus, host-microbe homeostasis was established within the first 24 h. In contrast, host-microbe homeostasis was disrupted after 48 h. The mucosa was damaged and detached from the implant, due to the induced downregulation of cell adhesion related genes. The immune response was enhanced by upregulation of additional genes related to the immune and inflammatory response and increased secretion of IL-1β, TNF-α, and CCL20. Moreover, bacterial distribution was altered, with an increased proportion of V. dispar. The disrupted host-microbe homeostasis could lead to incipient dysbiosis. This deeper understanding of the early host-microbe interaction at the peri-implant site may provide the basis for new strategies to improve the prevention and therapy of peri-implant diseases.
Project description:The goal of this study was to compare the gene expression profiles of chronically inflamed human peri-implant and chronically inflamed human periodontal tissues in order to elucidate potential changes at the molecular level. Cells out of the pocket depth of the inflamed peri-implant and periodontal ligament as well as from the middle third of healthy periodontal ligament were applied. Genome-wide gene expression was compared with the help of microarray analysis, and the data were validated by real-time RT-PCR. The expression rates of 14,239 genes were investigated and 2,079 of them were found differentially expressed by at least two-fold; the expression rates of 1,093 genes were significantly up-regulated and the expression rates of 986 genes were significantly down-regulated in inflamed peri-implant cells compared to inflamed periodontal cells. We focused on genes coding for extracellular matrix components and those that degrade them. Only genes of non-fibril-forming collagens (types IV, VI, VII, and XVII) were increased in inflamed peri-implant tissue, whereas only the genes of two fibril-forming collagens (types III and XVII) were decreased, suggesting that peri-implant tissue re-models faster than periodontal tissue. Furthermore, cathepsin D and cathepsin S might participate to a greater extent in connective tissue destruction of peri-implant tissue. The present investigation demonstrated that, despite their clinical similarities, periimplantitis and periodontitis are two different diseases at the genetic level. Keywords: inflammation, peri-implant, periodontal ligament cells