Project description:Human gingival epithelial cells (HGEp) and fibroblasts (HGF) are the main cell types of the peri-implant soft-tissue, with HGEp constantly being exposed to bacteria and HGF residing protected in the connective tissue as long as an intact mucosa-implant seal is preserved. Streptococcus oralis belongs to the commensal bacteria, is highly abundant at healthy implant sites, and might exert host modulatory effects on soft-tissue cells as described for other streptococci. Thus, we aimed to investigate the effects of S. oralis biofilm on HGEp as well as HGF. HGEp or HGF were grown on titanium separately and responded to S. oralis biofilm challenge. The cell condition of HGF was dramatically impaired after 4 hours showing a transcriptional inflammatory and stress response. In contrast, S. oralis challenge induced only transcriptional inflammatory response in HGEp with their cell condition remaining unaffected. Subsequently, HGF were susceptible compared to HGEp. The proinflammatory IL-6 was attenuated in HGF and CXCL8 in HGEp indicating a general tissue-protective role of S. oralis, forasmuch as the HGF are not exposed. In conclusion, an intact implant-mucosa interface is a prerequisite so that commensal biofilms can promote homeostasis for tissue protection.
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 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: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 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: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. Six of the patients where affected by periimplantitis. In situ dental implants where explanted because of inflammation and non-integration. From two patients, implants were explanted because of wrong placement. They where classified as implants with healthy periimplant tissue.