This study evaluated cell viability and cytokine release in immortalized human oral fibroblasts (hTERT-hNOFs) and keratinocytes (IHOK) exposed to a dental-impregnated gingival retraction cord. To prepare the extracts, dental gingival retraction cords impregnated with aluminum chloride hexahydrate were immersed in a cell culture medium for 24 h at 37 °C. hTERT-hNOFs and IHOK were cultured for 24 h. The cell culture medium was removed and extracts of the dental gingival retraction cords were added. After incubation with the extract solution, cell viability was evaluated using an MTT assay. The levels of the cytokines IL-1α and IL-8 were measured in the supernatants of each cell type. The cell viability after exposure to the extract solution for 10 min exceeded 70 % in both cell types. The ET50 values for hTERT-hNOF and IHOK were 35.75 and 28.98 min, respectively. For IHOK, the IL-1α level was (5.35 ± 5.22) pg/mL at 10 min, (3.58 ± 5.38) pg/mL at 20 min, and (2.85 ± 4.28) pg/mL at 60 min of exposure (p > 0.05). The IL-8 level in IHOK was (67.16 ± 18.70) pg/mL at 10 min, (78.36 ± 7.50) pg/mL at 20 min, and (111.9 ± 26.10) pg/mL at 60 min of exposure (p > 0.05). Cytokine release was not observed from hTERThNOFs. Based on these results, cell viability and cytokine release were confirmed in cells exposed to the impregnated gingival retraction cord. In addition, the application of the extracts to hTERT-hNOF and IHOK during the actual contact time and determination of ET50 may be beneficial for evaluating the biocompatibility of dental-impregnated gingival retraction cords.

When exposed to different types of bacteria in the oral cavity, denture based resins are prone to bacteria attachment. The purpose of this study was to investigate the physical, biological, and antimicrobial properties of denture base resins coated with Peony extract (200, 400, and 600 μg/mL). Specifically, the surface properties (microhardness, contact angle, and color change of the coated specimens), cell cytotoxicity (measured using MTT assay), and antimicrobial activity (against S. mutans (Streptococcus mutans) and C. albicans (Candida albicans) using a growth inhibition assay) were evaluated. The polyphenol content was measured using ultraviolet-visible (UV-vis) spectrometry. The experimental groups (specimens coated with Peony extract) and a control group (specimens coated without Peony extract) were statistically compared using a one-way analysis of variance and Tukey’s post-hoc tests. No statistically significant differences in surface properties or cell cytotoxicity were observed, which demonstrated their biocompatibility. Conversely, a statistically significant difference in antimicrobial activity was observed between the experimental and control groups after 48 h. This confirms the antimicrobial activity of the denture base resin coated with Peony extract and demonstrates that it is a promising dental material for preventing stomatitis.

Ips acuminatus is a minute bark beetle found in forest and can cause economic damage to pine and spruce trees. This beetle has well developed sensory system respond to both of visual and chemical stimuli. Both sexes have a pair of faceted compound eyes and another pair of knobbed antennae, work together to collect vital information. The antennae look similar in both sexes and consist of scape, pedicel, and segmented flagellum. The pedicel is the first segment by which the antenna is attached to the head and the scape is set in a membranous socket and surrounded by the antennal sclerite on which a single articulation occurs. The beetle’s antennae enlarge abruptly at the last segment of a flagellum giving the antenna a knobbed appearance. There are a number of sensory receptors, including olfactory and mechanical receptors. Here, the fine structural characteristics of the antennal sensory organs in male and female bark beetle Ips acuminatus (Coleoptera: Curculionidae: Scolytinae) were analysed with field emission scanning electron microscopy (FESEM).

The effect of Cu on the hydrogen reduction of powders was investigated by measuring the humidity change during a non-isothermal process of hydrogen reduction. The presence of Cu induced a shift in the reduction temperature and strongly affected the reduction processes of , which comprised the contained chemical vapor transport of . This study suggests that the surface of the Cu grains acts as a nucleation site for the reduction of to particles from or . Such an activated reduction process results in the deposition of Mo and particles on the surface of the Cu.