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This study aimed to investigate the inhibitory effects of Colocasia antiquorum var. esculenta (CA) on Porphyromonas gingivalis (P. gingivalis) growth, inflammation, and osteoclastogenesis. CA was effective in inhibiting the growth of P. gingivalis when applied together with an experimental fluoride varnish. CA also significantly decreased the release of interleukin-6, tumor necrosis factor-α, and nitric oxide from lipopolysaccharide-induced RAW 264.7 cells. No significant differences in viability were noted between the cells treated with CA and the controls. In addition, CA significantly attenuated osteoclast differentiation on bone marrow macrophages. In conclusion, CA inhibited the growth of P. gingivalis and showed anti-inflammatory and anti-osteoclastogenic effects. Therefore, CA may have the potential to act as a novel natural agent for preventing periodontitis.

We investigated the inhibitory effect of antibacterial agents mixed with experimental fluoride varnish (EFV) on Streptococcus mutans. The antibacterial agents used were (1 and 10) mM of xanthorrhizol, bakuchiol, bavachalcone, isobavachromene, and bavachromene. Agar diffusion tests were performed on S. mutans (1.1×1010 CFU/mL), using antibacterial agents without and with EFV. Bavachalcone showed the highest inhibition zone without and with EFV at both (1 and 10) mM (p 0.05), except xanthorrhizol and bakuchiol at 1 mM. All antibacterial agents were effective, while antibacterial agents with EFV co-formulations were more effective than EFV alone. Bavachalcone was the most effective agent against S. mutans, indicating its potential usefulness with fluoride varnish in preventing dental caries.

Background and Objectives:Asplenium incisum, a natural plant, is known to possess numerous pharmacological and biochemical properties. However, the inhibitory effect of A. incisum against Porphyromonas gingivalis and other factors related to periodontal disease have not yet been demonstrated. This study aimed to investigate the potential of A. incisum extract as a phytotherapeutic candidate for improving periodontal diseases by assessing its antibacterial, anti-inflammatory, and anti-osteoclastogenic activities. Materials and Methods: The inhibition of proliferation of P. gingivalis by A. incisum and the sustainability of its antibacterial activity were evaluated in this study. The production of inflammatory cytokines (tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)) and nitric oxide (NO) from lipopolysaccharide-stimulated RAW 264.7 cells was assessed using an enzyme-linked immunosorbent assay. To identify the anti-osteoclastogenic activity, tartrate-resistant acid phosphatase (TRAP) staining and TRAP activity analyses were performed on bone marrow macrophages. Results: The proliferation of P. gingivalis was significantly inhibited by A. incisum (p &lt, 0.001), and the antibacterial activity was sustained for up to 3 days. A. incisum showed anti-inflammatory activities by significantly decreasing the release of TNF-α, IL-6 (p &lt, 0.05), and NO (p &lt, 0.01). In addition, A. incisum significantly suppressed TRAP-positive cells and TRAP activity (at 30 μg/mL, p &lt, 0.01) without causing any cytotoxicity (p &gt, 0.05). Conclusions:A. incisum showed antibacterial, anti-inflammatory, and anti-osteoclastogenic activities, suggesting it has strong therapeutic potential against periodontal diseases.

We investigated the adhesion, proliferation and osteogenic functionality of osteoblasts cultured on titanium dioxide (TiO 2 ) nanotubes in response to different sterilization methods (dry autoclaving vs. wet autoclaving). We prepared various sizes (30–100 nm diameter) of TiO 2 nanotubes on titanium substrates by anodization, sterilized nanotubes by different conditions, and seeded osteoblast cells onto the nanotube surfaces with two different cell seeding densities (10,000 vs. 50,000 cells/well in 12-culture well). The result of this study indicates that the adhesion, proliferation and alkaline phosphatase activity of osteoblasts cultured on only the larger 70 and 100 nm TiO 2 nanotube arrays were dramatically changed by the different sterilization conditions at a low cell seeding density. However, with a higher cell seeding density (50,000 cells/well in 12-cell culture well), the results revealed no significant difference among altered nanotube geometry, 30–100 nm diameters, nor sterilization methods. Next, it was revealed that the nanofeatures of proteins adhered on nanotubular TiO 2 morphology are altered by the sterilization method. It was determined that this protein adhesion effect, in combination with the cell density of osteoblasts seeded onto such TiO 2 nanotube surfaces, has profound effects on cell behavior. This study clearly shows that these are some of the important in vitro culture factors that need to be taken into consideration, as well as TiO 2 nanotube diameters which play an important role in the improvement of cell behavior and functionality.

The aim of this study was to investigate the cytotoxic and nitric oxide (NO)-inducing effects of bismuth oxide (Bi(2)O(3))-containing Portland cement (BPC) on human dental pulp cells. We also assessed whether heme oxygenase-1 (HO-1) is involved in BPC-induced cytotoxicity in dental pulp cells. Cytotoxicity and NO production induced by BPC were higher than those induced by Portland cement at 12 and 24 hours, and the former gradually decreased to the level observed for PC. HO-1 and inducible nitric oxide synthase messenger RNA expressions in the BPC group showed maximal increase at 24 hours, and it gradually decreased with increasing cultivation time. Hemin treatment reversed the BPC-induced cytotoxicity, whereas zinc protoporphyrin IX treatment increased the cytotoxicity. These results suggested that NO production by BPC correlates with HO-1 expression in dental pulp cells. Moreover, BPC-induced HO-1 expression in dental pulp cells plays a protective role against the cytotoxic effects of BPC.

The purpose of this research was to prepare gold nanorod- (GNR-) grafted TiO2nanotubes by thiolactic acid treatment and evaluate remote-controlled drug elution and antibacterial activity by infrared (IR) light irradiation. Tetracycline used as an antibiotic was loaded into GNR-grafted TiO2nanotubes by using 2 w/v% polylactic acid solutions. A near-IR laser (830 nm) was used for remote-controlled IR light irradiation. Results of SEM, TEM, XRD, and EDX revealed that GNR chemically bonded to the whole surface of the TiO2nanotubes. An antibiotic release test revealed that on-off drug elution was triggered effectively by the photothermal effect of GNR grafted on TiO2nanotubes. Furthermore, an antibacterial agar zone test indicated that the annihilated zone ofStreptococcus mutansin the experimental group with IR light irradiation was significantly larger than that of the corresponding group without IR light irradiation (P<0.05). Therefore, GNR-grafted TiO2nanotubes would be expected to extend the limited usage of TiO2, which show photocatalytic activity only within the ultraviolet (UV) to IR region, thereby allowing the development of novel fusion technologies in the field of implant materials.

We have developed nitrogen-dopedTiO2nanotubes showing photocatalytic activity in the visible light region and have investigated the triggered release of antibiotics from these nanotubes in response to remote visible light irradiation. Scanning electron microscopy (SEM) observations indicated that the structure ofTiO2nanotubes was not destroyed on the conditions of 0.05 and 0.1 M diethanolamine treatment. The results of X-ray photoelectron spectroscopy (XPS) confirmed that nitrogen, in the forms of nitrite (NO2-) and nitrogen monoxide (NO), had been incorporated into theTiO2nanotube surface. A drug-release test revealed that the antibiotic-loadedTiO2nanotubes showed sustained and prolonged drug elution with the help of polylactic acid. Visible light irradiation tests showed that the antibiotic release from nitrogen-dopedTiO2nanotubes was significantly higher than that from pureTiO2nanotubes (P<0.05).

The aim of this study was to evaluate the reinforcing effects of three types of fibers at various concentrations and in different combinations on flexural properties of denture base resin. Glass (GL), polyaromatic polyamide (PA) and ultra-high molecular weight polyethylene (PE) fibers were added to heat-polymerized denture base resin with volume concentrations of 2.6%, 5.3%, and 7.9%, respectively. In addition, hybrid fiber-reinforced composite (FRC) combined with either two or three types of fibers were fabricated. The flexural strength, modulus and toughness of each group were measured with a universal testing machine at a crosshead speed of 5 mm/min. In the single fiber-reinforced composite groups, the 5.3% GL and 7.9% GL had the highest flexural strength and modulus; 5.3% PE was had the highest toughness. Hybrid FRC such as GL/PE, which showed the highest toughness and the flexural strength, was considered to be useful in preventing denture fractures clinically.

Statement of problem Current implant systems cannot completely prevent microleakage from the access holes of screw-retained implant prostheses, which may constitute risks to the clinical success of the implants. Purpose The purpose of this study was to evaluate the levels of microleakage through the access holes of screw-retained implant prostheses sealed with different materials. Material and methods An implant with an internal hexagonal configuration was connected to a temporary abutment with an acrylic resin crown. The apical 6.5 mm of the access hole was filled with 1 of the following materials: cotton pellet, silicone sealing material, vinyl polysiloxane, or gutta-percha. The remaining coronal 3 mm was sealed with composite resin. Cyclic loading with 21 N at 1 Hz was applied 16 000 times to the specimens in 0.5% basic fuchsin solution according to the long axis of the tooth. Basic fuchsin dye which penetrated into the internal wall of the abutment through the access hole was dissolved with methyl alcohol. Then the absorbance was measured by a spectrophotometer at 540 nm to evaluate the degree of microleakage. The results were statistically analyzed with 1-way ANOVA and the Tukey HSD test. Results From greatest to least, the levels of microleakage were in the following order: cotton pellet, silicone sealing material, vinyl polysiloxane, and gutta-percha. The microleakage associated with gutta-percha was not significantly different from that of vinyl polysiloxane. Conclusions When sealing the access holes of screw-retained implant prostheses, gutta-percha or vinyl polysiloxane would help reduce microleakage.

Osteoclasts are responsible for bone erosion in diseases as diverse as osteoporosis, periodontitis, and rheumatoid arthritis. Natural plant-derived products have received recent attention as potential therapeutic and preventative drugs in human disease. The effect of rotenone in RANKL-induced osteoclast differentiation was examined in this study. Rotenone inhibited RANKL-mediated osteoclast differentiation in bone marrow macrophages (BMMs) in a dose-dependent manner without any evidence of cytotoxicity. The mRNA expression of c-Fos, NFATc1, TRAP, and OSCAR in RANKL-treated BMMs was inhibited by rotenone treatment. Rotenone strongly inhibited p38 and ERK phosphorylation and I-kappaB degradation in RANKL-stimulated BMMs, and did not inhibit JNK phosphorylation. Further, RANKL-induced c-Fos and NFATc1 protein expression was suppressed by rotenone. Rotenone additionally inhibited the bone resorptive activity of differentiated osteoclasts. A lipopolysaccharide (LPS)-induced bone erosion study was also performed to assess the effects of rotenone in vivo. Mice treated with rotenone demonstrated marked attenuation of bone erosion based on Micro CT and histologic analysis of femurs. These results collectively suggested that rotenone demonstrated inhibitory effects on osteoclast differentiation in vitro and suppressed inflammatory bone loss in vivo. Rotenone may therefore serve as a useful drug in the prevention of bone loss.

It has been reported that Janus tyrosine kinase (JAK)-dependent signaling pathways play a critical role in the pathogenesis of numerous malignancies and immune reactions, and inhibition of JAK has been implicated in cell growth inhibition. The role which JAK has on osteoclast differentiation and anti-bone resorptive activity is not well understood. In this study, we investigated the effects of a pan-JAK inhibitor, pyridone 6, on osteoclast differentiation and bone-resorption in vitro and ex vivo. Pyridone 6 inhibited osteoclast differentiation in mouse bone marrow macrophage (BMM) cultures stimulated by the receptor activator of nuclear factor-kappaB (NF-kappaB) ligand (RANKL) and co-cultures of bone marrow cells and osteoblasts. Pyridone 6 suppressed the expression of c-Fos and nuclear factor of activated T cells (NFAT) c1 in BMMs. It also inhibited the bone resorptive activity of mature osteoclasts that was accompanied by disruption of actin rings. Pyridone 6 also suppressed I-kappaB degradation and extracellular signal-regulated kinase (ERK) in mature osteoclasts, suggesting that these are the key molecules that pyridone 6 targets in the inhibition of osteoclast function. These results demonstrate inhibition of JAK may be useful for the treatment of bone-resorptive diseases, such as osteoporosis.

The purpose of this study was to examine the effect of acid-base surface treatment on the fracture resistance, which is one of main mechanical property, of zirconia restoration in order to improve the bonding characterization between zirconia core and ceramic veneer in bi-layered all ceramic restoration system. 10% hydrofluoric acid (HF) and 1 M sodium hydroxide (NaOH) were used as acid and base chemical solutions for surface treatment, respectively. Fracture-resistance tests were performed to investigate the effects of acid and liner treatment on the improvement of the bonding strength between veneer ceramics and zirconia. Specimens were divided into five groups (n = 4) according to the type of surface treatment: (1) Group A, no treatment (control); (2) Group B, liner treatment; (3) Group C, 10% HF etching for 60 s; (4) Group D, 10% HF etching for 60 s and liner treatment. All results of fracture resistance test showed that there were no significant differences between surface treatment types. Failure mode observation indicated that most specimens of Cerasys, Zmatch, and ICE groups showed cohesive failure mode regardless of the method of surface treatment. From the results of study, the short (1 min) treatment of zirconia in HF solution is supposed to be suitable for improving bond strength of zirconia restoration, but long (more than 30 min) treatment of zirconia in HF solution is expected to deteriorate the zirconia structure. Also, several factors such as liner and acid treatment, which improve the fracture resistance of zirconia restoration, seemed to depend on the type of zirconia materials.