Project description:Deteriorated bone quality in osteoporosis challenges the success of implants, which are in urgent need for better early osseointegration as well as antibacterial property for long-term stability. As osteoporotic bone formation tangles with angiogenic clues, the relationship between osteogenesis and angiogenesis has been a novel therapy target for osteoporosis. However, few designs of implant coatings take the compromised osteoporotic angiogenic microenvironment into consideration. Here, we investigated the angiogenic effects of bioactive strontium ions of different doses in HUVECs only and in a co-culture system with BMSCs. A proper dose of strontium ions (0.2-1 mM) could enhance the secretion of VEGFA and Ang-1 in HUVECs as well as in the co-culture system with BMSCs, exhibiting potential to create an angiogenic microenvironment in the early stage that would be beneficial to osteogenesis. Based on the dose screening, we fabricated a bioactive titanium surface doped with zinc and different doses of strontium by plasma electrolytic oxidation (PEO), for the establishment of a microenvironment favoring osseointegration for osteoporosis. The dual bioactive elements augmented titanium surfaces induced robust osteogenic differentiation, and enhanced antimicrobial properties. Augmented titanium implant surfaces exhibited improved bone formation and bone-implant contact under comprehensive assessment of an in vivo bone-implant interface. In conclusion, zinc- and strontium-augmented titanium surface benefits the osseointegration in osteoporosis via promoting osteogenic differentiation, exerting antibacterial efficacy, and stimulating early angiogenesis.
Project description:ObjectivesThis study determined whether implant surfaces that promote osseointegration in normal rats can promote osseointegration in osteoporotic rats without pharmacologic intervention.Materials and methodsVirgin female 8-month-old CD Sprague Dawley rats (N = 25) were ovariectomized. At 6 weeks, microstructured/non-nanostructured/hydrophobic, microstructured/nanostructured/hydrophobic, or microstructured/nanostructured/hydrophilic Ti implants (Ø2.5 × 3.5 mm; Institut Straumann AG, Basel, Switzerland) were placed in the distal metaphysis of each femur. At 28 days, bone quality and implant osseointegration were assessed using microCT, histomorphometrics, and removal torque values (RTVs). Calvarial osteoblasts were isolated and cultured for 7 days on Ø15 mm Ti disks processed to exhibit similar surface characteristics as the implants used for the in vivo studies. The phenotype was assessed by measuring the production of osteocalcin, osteoprotegerin, osteopontin, BMP2, VEGF, and RANKL.ResultsMicrostructured/nanostructured/hydrophilic implants promoted increased bone-to-implant contact and RTVs in vivo and increased osteoblastic marker production in vitro compared to microstructured/non-nanostructured/hydrophobic and microstructured/nanostructured/hydrophobic implants, suggesting that osseointegration occurs in osteoporotic animals, and implant surface properties improve its rate.ConclusionsAlthough all modified implants were able to osseointegrate in rats with OVX-induced osteoporosis without pharmacologic intervention, the degree of osseointegration was greater around microstructured/nanostructured/hydrophilic implant surfaces. These results suggest that when appropriate microstructure is present, hydrophilicity has a greater influence on Ti implant osseointegration compared to nanostructures. Moreover, modified implant surfaces can exert their control over the altered bone turnover observed in osteoporotic patients to stimulate functional osseointegration. These results provide critical insight for developing implants with improved osseointegration in patients with metabolic disorders of bone remodeling.
Project description:BackgroundThe present observational clinical investigation is based on the hypothesis that subgingival yeast carriage (SYC) is higher in cigarette-smokers with peri-implant mucositis (PM) than non-smokers with and without PM.ObjectiveThe aim was to assess peri-implant clinical profile and SYC among cigarette-smokers with PM.MethodologyParticipants were divided into four groups: Group-1-Cigarette-smokers with PM; Group-2-Cigarette-smokers without PM; Group-3-Non-smokers with PM; and Group-4-Non-smokers without PM. Information on duration and daily frequency of cigarette smoking (pack years), age, gender, familial history of smoking and most recent visit to a dentist and/or dental hygienist was collected. The following information was retrieved from healthcare records: implant dimensions, implant insertion torque, depth of insertion (credidastal or subcrestal), implant abutment connection, jaw location, implant surface characteristic, and mode of implant prosthesis retention. Peri-implant modified plaque and gingival indices (mPI and mGI), probing depth (PD) and crestal bone loss were recorded. Subgingival biofilm samples were collected, and SYC was recorded in colony forming units per milliliter (CFU/ml). P < 0.05 were considered statistically significant.ResultsEighty male individuals (20, 19, 21 and 20 individuals were included in groups 1, 2, 3 and 4, respectively) were included. The mPI was higher in Group-1 than groups 2 (P < 0.05) and 4 (P < 0.05). The mPI was higher in Group-3 than groups 2 (P < 0.05) and 4 (P < 0.05). The mGI was higher in Group-3 than groups 1 (P < 0.05), 2 (P < 0.05) and 4 (P < 0.05). The PD was higher in Group-1 than groups 2 (P < 0.05) and 4 (P < 0.05). The PD was higher in Group-3 than Groups 2 (P < 0.05) and 4 (P < 0.05). The CFU/ml were higher in Group-1 than groups 2 (P < 0.05) and 4 (P < 0.05). The CFU/ml were higher in Group-3 than groups 2 (P < 0.05) and 4 (P < 0.05).ConclusionPeri-implant soft-tissue inflammatory parameters are worse and SYC is higher in moderate smokers than light smokers with PM and non-smokers without PM.
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 article, we propose a simple scheme of using berberine (BBR) to modify porous calcium phosphate ceramics (named PCPC). These BBR molecules regulate the crystallization of hydroxyapatite nanorods on PCPC. We found that these nanorods and the adsorbed BBR changed the interface micro-environment of PCPC by SEM images. The microenvironment of PCPC surface is essential for promoting BMSCs' proliferation and differentiation. These results demonstrated that PCPC/BBR markedly improved the bone regeneration of osteoporosis rats. Moreover, PCPC/BBR had significantly increased the expression levels of ALP, osteocalcin and bone morphogenetic protein2 and RUNX2 in BMSCs originated from osteoporosis rats.
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.