ABSTRACT
The purpose of this study was to investigate the effect of sodium butyrate (SB)-containing calcium sulfate (CaS) bone graft on fibroblasts, oral mucosa and bone tissue. All the tests were performed according to the standard method of ISO 10993. For the cytotoxicity assay, the SB/CaS mixture was set for 24 h, and was placed on the layer of fibroblasts covered with agar for 24 h. Most cells under and near the mixture were viable and showed the morphology of healthy cells, which indicated that there was no cytotoxicity. The effect of SB/CaS mixture on oral mucosa was evaluated using the hamster cheek pouch. There were no signs of tissue responses indicating inflammatory reactions to SB/CaS mixture. Finally, there was no appearance of inflammatory cells, and normal tissue histology was shown by the implantation of SB/CaS mixture to the femur of rabbits. Therefore, it was considered that the SB/CaS mixture was non-cytotoxic and non-irritant to oral mucosa and bone tissue.
ABSTRACT
Phosphatidylserine (PS) mimics the anti-inflammatory effect of apoptotic cells by binding to the PS receptor of macrophages. In this study, the effect of PS-modified polylactide-co-glycolide (PLGA) nanoparticles on macrophage polarization was investigated.PLGA nanoparticles (PLGAnPs) containing phosphatidylcholine (PC) and PS were prepared using the emulsificationsolvent-evaporation (ESE) technique and classified as follows: 1) PC 100% (PCnP); 2) PS:PC = 50:50 (PSPCnP); and 3) PS 100% (PSnP). PS-grafted PLGAnPs tended to inhibit LPS-induced morphological change into M1 macrophages and mRNA expression of the M1 markers (TNF-α, IL-1β, IL-6, IL-12p40, CD86, and iNOS). In particular, the expressions of TNF-α, IL-6, and IL-12p40 were significantly decreased in the PSPCnP group, as compared to those of the positive control and and PLGAnP groups (p<0.05). Therefore, the study results demonstrate the potential of PS-grafted PLGAnPs in attenuating inflammation and modulating the drug delivery system.
ABSTRACT
The purpose of this study was to evaluate the effect of dicalcium phosphate dihydrate (DCPD) on the biocompatibility of mineral trioxide aggregate (MTA). DCPD was added to MTA (OrthoMTA) to suppress the increase in pH of MTA during hardening, and the change of pH, cytotoxicity, and subcutaneous inflammation reactions in mouse model were observed. The pH of OrthoMTA and DCPD-OrthoMTA at 1st day in phosphate-buffered saline was 12.5 and 12.8, respectively. At 19th day, the pH was 11.6 (OrthoMTA) and 8.8 (DCPD-OrthoMTA). Cytotoxicity of DCPD-OrthoMTA extract was lesser than that of OrthoMTA at high concentration (above 50%) (p<0.05). No significant differences appeared in subcutaneous inflammatory reactions among ProRoot MTA, OrthoMTA and DCPD-OrthoMTA. Therefore, it is likely that there is no apparent relationship between the cytotoxicity and subcutaneous inflammation in our experimental conditions.
ABSTRACT
The purpose of this study was to evaluate the effect of dicalcium phosphate dihydrate (DCPD) on the biocompatibility of mineral trioxide aggregate (MTA). DCPD was added to MTA (OrthoMTA) to suppress the increase in pH of MTA during hardening, and the change of pH, cytotoxicity, and subcutaneous inflammation reactions in mouse model were observed. The pH of OrthoMTA and DCPD-OrthoMTA at 1st day in phosphate-buffered saline was 12.5 and 12.8, respectively. At 19th day, the pH was 11.6 (OrthoMTA) and 8.8 (DCPD-OrthoMTA). Cytotoxicity of DCPD-OrthoMTA extract was lesser than that of OrthoMTA at high concentration (above 50%) (p<0.05). No significant differences appeared in subcutaneous inflammatory reactions among ProRoot MTA, OrthoMTA and DCPD-OrthoMTA. Therefore, it is likely that there is no apparent relationship between the cytotoxicity and subcutaneous inflammation in our experimental conditions.
ABSTRACT
PURPOSE: This study aimed to evaluate the effects of fibronectin and oxysterol immobilized on machined-surface dental implants for the enhancement of cell attachment and osteogenic differentiation, on peri-implant bone healing in the early healing phase using an experimental model in dogs. METHODS: Five types of dental implants were installed at a healed alveolar ridge in five dogs: a machined-surface implant (MI), apatite-coated MI (AMI), fibronectin-loaded AMI (FAMI), oxysterol-loaded AMI (OAMI), and sand-blasted, large-grit, acid-etched surface implant (SLAI). A randomly selected unilateral ridge was observed for 2 weeks, and the contralateral ridge for a 4-week period. Histologic and histometric analyses were performed for the bone-to-implant contact proportion (BIC) and bone density around the dental implant surface. RESULTS: Different bone healing patterns were observed according to the type of implant surface 2 weeks after installation; newly formed bone continuously lined the entire surfaces in specimens of the FAMI and SLAI groups, whereas bony trabecula from adjacent bone tissue appeared with minimal new bone lining onto the surface in the MI, AMI, and OAMI groups. Histometric results revealed a significant reduction in the BIC in MI, AMI, and OAMI compared to SLAI, but FAMI demonstrated a comparable BIC with SLAI. Although both the BIC and bone density increased from a 2- to 4-week healing period, bone density showed no significant difference among any of the experimental and control groups. CONCLUSIONS: A fibronectin-coated implant surface designed for cell adhesion could increase contact osteogenesis in the early bone healing phase, but an oxysterol-coated implant surface designed for osteoinductivity could not modify early bone healing around implants in normal bone physiology.
Subject(s)
Animals , Dogs , Alveolar Process , Bone and Bones , Bone Density , Cell Adhesion , Dental Implants , Fibronectins , Models, Theoretical , Osteogenesis , Physiology , Surface Properties , TitaniumABSTRACT
PURPOSE: The purpose of this study was to characterize the osseointegration of the fibronectin-coated implant surface. METHODS: Sand-blasted, large-grit, acid-etched (SLA) surface implants, with or without a thin calcium phosphate and fibronectin coating, were placed in edentulous mandibles of dogs 8 weeks after extraction. All dogs were sacrificed forhistological and histomorphometric evaluation after 4- and 8-week healing periods. RESULTS: All types of implants were clinically stable without any mobility. Although the bone-to-implant contact and bone density of the SLA implants coated with calcium phosphate (CaP)/fibronectin were lower than the uncoated SLA implants, there were no significant differences between the uncoated SLA surface group and the SLA surface coated with CaP/fibronectin group. CONCLUSIONS: Within the limits of this study, SLA surfaces coated with CaP/fibronectin were shown to have comparable bone-to-implant contact and bone density to uncoated SLA surfaces.