The aim was to analyse the influence of an apical ledge on root canal disinfection. Forty-four single-rooted teeth were micro-CT scanned and inoculated with Enterococcus faecalis. In Group S shaping was performed with ProTaper Next (PTN) up to X3 at working length (WL). In Group L an apical ledge was created with K-Files #40 and shaping completed up to PTN X3. NaOCl 5% and EDTA 10% irrigant solutions were alternated. Confocal laser scanning microscope (CLSM) and viability staining were used to analyse the proportions of dead (red) and live (green) bacteria and penetration ability inside dentinal tubules. Data were analysed with the Mann-Whitney test with Bonferroni correction (p < 0.05). In Group L the amount of red fluorescence resulted significantly lower, and penetration ability was decreased in the apical and middle portion (p < 0.05). The presence of an apical ledge may negatively influence the disinfection both in the apical and middle third.

UNASSIGNED: The objective of the study was to compare and evaluate the depth of penetration of an epoxy resin-based sealer following a final rinse of 17% ethylenediaminetetraacetic acid (EDTA) and 18% 1-hydroxyethylidene 1, 1-diphosphonate (HEDP), with diode laser and passive ultrasonic activation (PUI): an in vitro confocal laser scanning microscopy study.
UNASSIGNED: Fifty-two extracted human mandibular premolar teeth with single root and single canal were selected. They were disinfected in 0.1% thymol solution, cleaned of calculus and soft tissues, and stored in 0.1% thymol solution till use. All teeth were radiographed and selected as per the inclusion and exclusion criteria. The teeth were decoronated using a diamond disk under copious water spray to acquire a standardized root length of 14 mm. Working length was established by inserting a size 10-K file into each root canal until it is visible at the apical foramen and by subtracting 1 mm from the recorded length. Instrumentation of the root canal was done till master apical file size of F3 using ProTaper universal, rotary instruments. The canals were irrigated with 2 mL of 3% sodium hypochlorite between successive files. Teeth were randomly divided into four subgroups n = 12 according to the intervention. Passive ultrasonic irrigation and diode laser were used to activate the irrigants. Final irrigation was performed with distilled water. These specimens were examined using confocal laser scanning microscope (OLYMPUS FLUOVIEW FV 3000) for dentinal tubule penetration of the sealer. Two-way ANOVA test and Tukey\'s multiple post hoc test were used for statistical analysis.
UNASSIGNED: Highly significant difference was seen between the groups with EDTA and HEDP, with HEDP demonstrating the highest penetration. Among the activation techniques used in this study, PUI showed the highest penetration of the sealer. The least penetration was seen with diode laser activation and EDTA.
UNASSIGNED: The irrigation activation techniques significantly influence the penetration of sealer into root dentinal tubules. When penetration of sealer with different irrigation techniques and irrigants was evaluated, significant greater level of sealer penetration was attained with PUI activation of HEDP.

UNASSIGNED: Smear layer clearance and sealer penetration into dentinal tubules play a crucial role in root canal treatment. Hence, efficient irrigation is a crucial component of the root canal debridement. This in vitro study\'s objective was to assess the effectiveness of passive ultrasonic activation and Erbium: yttrium-aluminum-garnet (Er: YAG) laser-activated irrigation on irrigation solution penetration and sealer penetration into dentinal tubules.
UNASSIGNED: The aim of this study was to evaluate and compare the dentinal tubule penetration of epoxy resin-based sealer and bioceramic sealer after ultrasonic agitation and Er: YAG laser activation of the irrigant.
UNASSIGNED: This was an in vitro study.
UNASSIGNED: Extracted tooth samples (n = 42) into 06 groups (Group A-F) with 7 samples in each group. Postobturation transverse section was made and assessed under a confocal laser scanning microscope for the total dentinal tubule penetration area and recorded as the mean apical, middle, and coronal penetration.
UNASSIGNED: One-way analysis of variance test, followed by post hoc was used.
UNASSIGNED: The intergroup comparison showed that Group E and Group F have significantly more penetration as compared to the controls and ultrasonic irrigation, P < 0.001 and P < 0.01, respectively.
UNASSIGNED: Er: YAG laser with AH plus sealer has the highest penetration in all the sections of tooth, followed by CeraSeal sealer.

Adequate root canal sealing is essential for the success of endodontic treatment. There are numerous techniques available; identifying simple and efficient techniques is important to provide good patient care. The purpose of the study was to compare the maximum penetration depth and the percentage of sealant penetration of an endodontic sealer into dentine tubules using cold lateral condensation, continuous wave, and hybrid techniques, and to contrast the effectiveness of two different tapered gutta-percha master cones (0.02 and 0.04). A sample of sixty single root teeth was used. Six experimental groups were formed from the three filling techniques and the two tapered master cones. Images were acquired using a confocal laser scanning microscope. In the apical root third, the penetration percentage was higher in the hybrid compared with the continuous wave technique. The results indicated a higher penetration depth of hybrid compared with cold lateral condensation in the middle and coronal thirds, and in the apical third, a higher penetration was identified in the hybrid group compared with the continuous wave group. No significant differences in penetration were found comparing 0.02 with 0.04 taper gutta-percha groups. The coronal cross-sections presented a higher penetration than the apical third sections. In conclusion, the hybrid technique a had higher maximum sealer penetration than the continuous wave in the apical third, and the coronal third hybrid and continuous wave had a higher penetration than cold lateral condensation.

Aquatic ecosystems are facing increasing exposure to pollutants, posing potential threats to the stability and wellness of aquatic species. This study focused on evaluating the impacts of single and combined exposure to 80 nm polystyrene nanoplastics (PS-NPs, 0.1, 1, 10, 20 mg/L) and decabromodiphenyl ether (BDE-209, 300 ng/L) for 14 days on the bioaccumulation, growth, photosynthesis and oxidative stress in the free-floating fern Salvinia natans. PS-NPs primarily accumulated in the epidermis and trichomes of S. natans. Meanwhile, the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were significantly increased, while those for peroxidase (POD), catalase (CAT), total antioxidant capacity (T-AOC), and relative growth rate (RGR) decreased. Furthermore, the chlorophyll contents in submerged leaves were decreased, while those in floating leaves were increased at PS-NPs concentrations of 0.1 and 1 mg/L. However, the chlorophyll contents in both submerged and floating leaves displayed a decreasing trend with increasing concentrations of PS-NPs. Under the co-exposure of PS-NPs and BDE-209, the contents of MDA were significantly elevated, whereas CAT, POD, SOD, T-AOC and RGR were significantly decreased (p < 0.05). Our results revealed that, compared to single exposure, more pronounced ecotoxic effects are observed in S. natans under co-exposure to PS-NPs and BDE-209. These findings offer valuable perspectives into the possible environmental risks of BDE-209 and PS-NPs in freshwater ecosystems, contributing to the development of effective management strategies for protecting aquatic organisms and ecosystems. This research highlights the urgent need to understand the toxic effects of emerging contaminants on different aquatic organisms, emphasizing the importance of protecting and preserving aquatic ecosystems.

The effects of Y on the solidification process of 7Mo super austenitic stainless steel (7MoSASS) under low cooling rate conditions (10 °C/min) were investigated using high-temperature confocal laser scanning microscopy (HT-CLSM). The in situ observation results indicate that Y samples promote an increase in austenite nucleation density. After 10 s of nucleation, the nucleation density increased by 149.53/mm2 for the Y sample. Furthermore, variance analysis indicated that Y addition improved the uniformity of the 7MoSASS solidification microstructure under low cooling rate conditions. The Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory results showed that when the solid phase ratio was 0.5, the nucleation mode of the Y sample transitioned from saturation site nucleation to saturation site nucleation + Avrami nucleation. YAlO3 has a low lattice disregistry value with austenite, making it a suitable heterogeneous nucleation core for promoting the early nucleation of austenite. During the late stages of solidification, Y accumulates in the residual liquid phase, providing a greater degree of compositional undercooling. SEM-EDS analysis showed that Y contributed to the refinement of the 7MoSASS solidification microstructure, with the proportion of precipitated phases decreasing by approximately 7.5%. Cr and Mo were the main elements exhibiting positive segregation in 7MoSASS, and the Cr segregation ratio increased in the Y sample, while the Mo segregation ratio decreased.

The properties of centimeter-sized thin-film compound semiconductors depend upon the morphology and chemical composition of the multiple submicrometer-thick elemental and alloy precursor layers from which they are synthesized. The challenge is to characterize the individual precursor layers over these length scales during a multistep synthesis without altering or contaminating them. Conventional electron and X-ray-based morphological and compositional techniques are invasive, require preparation, and are thus incompatible with in-line synthesis processes. In a proof-of-concept study, we applied confocal laser scanning microscopy (CLSM) as a noninvasive optical imaging technique, which measures three-dimensional surface profiles with nanoscale resolution, to this challenge. Using an array of microdots containing Cu(In,Ga)Se2 semiconductor layers for solar cells as an example, we performed CLSM correlative studies to quantify morphological and layer thickness changes during four stages of a thin-film compound synthesis. Using simple assumptions, we measured the micrometer-scale spatially resolved chemical composition of stacked precursor layers to predict the final material phases formed and predict relative device performance. The high spatial resolution, coupled with the ability to measure sizeable areas without influencing the synthesis at high speed, makes CLSM an excellent prospect for research and quality control tool for thin films.

Exopolysaccharides (EPS) are essential constituents of the extracellular matrix within oral biofilms and are significantly influenced by the local microenvironment. This study aimed to investigate the impact of two distinct antimicrobial agents, DJK-5 and chlorhexidine (CHX), on the EPS volume and pH levels in oral biofilms.
Oral biofilms obtained from two donors were cultured on hydroxyapatite discs for durations of 3 days, 1 week, 2 weeks, 3 weeks, and 4 weeks. Subsequently, these biofilms were subjected to treatment with 10 µg/mL DJK-5 or 2% CHX for 3 min. The impact of these antimicrobial treatments on factors such as the proportion of dead bacterial, in situ pH, and EPS volume within the biofilms was assessed using corresponding fluorescent probes. The examination was carried out utilizing confocal laser scanning microscopy, and the resulting images were analyzed with a focus on the upper and lower layers of the biofilm, respectively.
DJK-5 exhibited a more potent bactericidal effect compared to CHX across the 3-day to 4-week duration of the biofilm (P < 0.05). The biofilms were acidic, with the upper layer being less acidic than the lower layer (P < 0.05). Both antimicrobial agents increased the pH, but DJK-5 had a greater effect than CHX (P < 0.05). The volume of EPS was significantly lower in DJK-5 treated biofilms compared to that of CHX, regardless of age or layer (P < 0.05).
DJK-5 exhibited superior effectiveness in reducing viable bacteria and EPS volume, as well as in raising extracellular pH, as compared to chlorhexidine.

Porous phase-separated ethylcellulose/hydroxypropylcellulose (EC/HPC) films are used to control drug transport out of pharmaceutical pellets. Water-soluble HPC leaches out and forms a porous structure that controls the drug transport. Industrially, the pellets are coated using a fluidized bed spraying device, and a layered film exhibiting varying porosity and structure after leaching is obtained. A detailed understanding of the formation of the multilayered, phase-separated structure during production is lacking. Here, we have investigated multilayered EC/HPC films produced by sequential spin-coating, which was used to mimic the industrial process. The effects of EC/HPC ratio and spin speed on the multilayer film formation and structure were investigated using advanced microscopy techniques and image analysis. Cahn-Hilliard simulations were performed to analyze the mixing behavior. A gradient with larger structures close to the substrate surface and smaller structures close to the air surface was formed due to coarsening of the layers already coated during successive deposition cycles. The porosity of the multilayer film was found to vary with both EC/HPC ratio and spin speed. Simulation of the mixing behavior and in situ characterization of the structure evolution showed that the origin of the discontinuities and multilayer structure can be explained by the non-mixing of the layers.

Detergency determination for single polymeric fibers is of significant importance to screening effective detergents for laundry, but remains challenging. Herein, we demonstrate a novel and effective method to quantify the detergency for single polymeric fibers using a confocal laser scanning microscope (CLSM). It was applied to visualize the oil-removing process of single polymeric fibers and thus assess the detergency of various detergents. Four typical surfactants were selected for comparison, and a compounded detergent containing multiple components (e.g., anionic and nonionic surfactants, enzymes) was demonstrated to be the most effective and powerful soil-removing detergent because more than 50% of oil on the cotton fiber could be easily removed. Moreover, the oil removal process of three kinds of fibers (i.e., cotton, viscose, and polyester) was imaged and monitored by confocal microscopy. It was found that the percentage of the detergency of a single polyester fiber exceeded 70%, which is much higher than that of cotton and viscose fibers (~50%), which may be due to its relatively smooth surface. Compared to traditional methods, the CLSM imaging method is more feasible and effective to determine the detergency of detergents for single polymeric fibers.