Assessment of different irrigation techniques on the penetration depth of different sealers into dentinal tubules by confocal laser scanning microscope: An in vitro comparative study.

Background: The effective disinfection of the entire root canal system aids in the penetration of irrigants into the dentinal tubules further improving sealer penetration and achieving a three-dimensional seal in endodontically treated teeth. Various final irrigation techniques can be employed to achieve this goal. Therefore, this study intended to assess and compare the efficacy of three final irrigation techniques on the depth of penetration of two root canal sealers into dentinal tubules using confocal laser scanning microscope (CLSM). Methods: Forty-eight single-rooted mandibular premolars were selected and decoronated to a length of 12 mm. All the samples were prepared using ProTaper Gold rotary files and divided into three groups: Group 1 - Conventional syringe irrigation (CSI), Group 2 - passive ultrasonic irrigation (PUI), and Group 3 - Pro-agitator tip system (PATS). Each group was divided into two subgroups: Subgroup A - AH Plus and Subgroup B - GuttaFlow Bioseal (GFB). Then, sealers were mixed with 0.1% rhodamine B dye and the samples were obturated. All the samples were sectioned at 2 mm and 5 mm from the apex and visualized under confocal laser scanning microscope (CLSM) (10×) for maximum mean penetration depth and percentage of sealer penetration. Statistical analysis was done using the independent t-test and one-way analysis of variance test, followed by Tukey's Post hoc analysis. Results: PUI performed better in the apical third, whereas PUI and PATS showed comparable results in the middle third for both depth and percentage of sealer penetration. Among the two sealers, GFB performed better than AH Plus in both the apical and middle third. These values were statistically significant. (P < 0.05). Conclusion: Final irrigation activation with PUI or PATS can significantly improve sealer penetration. The average depth of penetration of GFB both at the middle and apical third of the root was significantly superior to AH Plus.

A Facile Two-Step Hydrothermal Synthesis of Co(OH)2@NiCo2O4 Nanosheet Nanocomposites for Supercapacitor Electrodes.

The composites of NiCo2O4 with unique structures were substantially investigated as promising electrodes. In this study, the unique structured nanosheets anchored on nickel foam (Ni foam) were prepared under the hydrothermal technique of NiCo2O4 and subsequent preparation of Co(OH)2. The Co(OH)2@NiCo2O4 nanosheet composite has demonstrated higher specific capacitances owing to its excellent specific surface region, enhanced rate properties, and outstanding electrical conductivities. Moreover, the electrochemical properties were analyzed in a three-electrode configuration to study the sample material. The as-designed Co(OH)2@NiCo2O4 nanosheet achieves higher specific capacitances of 1308 F·g-1 at 0.5 A·g-1 and notable long cycles with 92.83% capacity retention over 6000 cycles. The Co(OH)2@NiCo2O4 nanosheet electrode exhibits a long life span and high capacitances compared with the NiCo2O4 and Co(OH)2 electrodes, respectively. These outstanding electrochemical properties are mainly because of their porous construction and the synergistic effects between NiCo2O4 and Co(OH)2. Such unique Co(OH)2@NiCo2O4 nanosheets not only display promising applications in renewable storage but also reiterate to scientists of the unlimited potential of high-performance materials.

Noncytotoxic Dy3+ -activated glass emits cool white light for near ultraviolet-based white light-emitting diodes, visible lasers, and biomedical applications.

Using the melt quenching technique, a lithium zinc borate glass (LZB) system with trivalent dysprosium ions (Dy3+ ) was synthesized, and the luminescence and lasing properties of these materials were examined for the generation of white light. Structural investigation through X-ray diffraction revealed that the prepared glass had an amorphous nature. The optimized glass containing 0.5 Dy3+ had a direct optical band gap of 2.782 eV and an indirect optical band gap of 3.110 eV. A strong excitation band at 386 nm (6 H15/2 →4 I13/2 ) was recognized in the ultraviolet (UV) light region of its excitation spectrum. Emission bands could be seen in the photoluminescence spectrum at 659, 573, and 480 nm under the 386 nm excitation. These transitions of emission resembled electronic transitions such as (4 F9/2 →6 H11/2 ), (4 F9/2 →6 H13/2 ), and (4 F9/2 →6 H15/2 ). In a pristine glass matrix, the higher intensity ratio of yellow to blue can result in the production of white light. The optimized Dy3+ ion concentration was observed to be 0.5 mol%. In addition, an analysis of lifetime decay was conducted for all synthesized glasses, and their decay trends were systematically investigated. Noticeably, we assessed the photometric parameters and found that they were close to the white light standard. Furthermore, a cytotoxicity study was carried out using lung fibroblast (WI-38) cell lines for the optimized 0.5Dy3+ -doped LZB glass and it appeared to be noncytotoxic. It is clear from the results that the noncytotoxic LZB glass doped with 0.5 Dy3+ ions could be a suggestive choice for the manufacture of white light-emitting diodes and lasers using near-UVs.

An in vitro assessment of cytotoxicity and genotoxicity of root repair materials.

Background: The success of the root-end procedure depends on the regeneration of the functional periodontal attachment system, including the cementum on the resected root-end surface, periodontal ligament (PDL), and alveolar bone. As root end filling materials remain in close contact with live periapical tissues, they may influence the endodontic treatment outcome. Aim: To assess and compare the cytotoxicity and genotoxicity of three root repair materials, mineral trioxide aggregate (MTA), endosequence, and geristore in human-cultured periodontal ligament fibroblasts. Materials and Methods: Cultured human periodontal ligament fibroblasts of the third passage were used in the study. They were placed in contact with the root repair materials. The cytotoxic effect on PDL fibroblasts was determined by (3-(4,5-dimethylthiazol-2-yl)-2,5-tetrazolium bromide) assay after 24 hours and 48 hours intervals. Cell viability was determined using an inverted phase contrast microscope. The genotoxic effect on the periodontal fibroblast cells was determined by comet assay using imaging software. Statistical Analysis Used: Data were analyzed using Tukey's multiple comparison test and Dunnett's multiple test. Results: All the test materials showed higher cytotoxicity and genotoxicity at the 48th hour interval with a statistically significant difference from the control group (P < 0.05). MTA was shown to be least cytotoxic and genotoxic to PDL fibroblasts, followed by endosequence root repair material and geristore at 24 hour and 48 hour intervals. Conclusion: The cytotoxicity and genotoxicity of MTA were the least compared to endosequence and geristore on human-cultured PDL fibroblasts.

Non-cytotoxic Dy3+ activated La10W22O81 nanophosphors for UV based cool white LEDs and anticancer applications.

White-light-emitting La10W22O81 (LWO): xDy3+ (0.5 ≤ x ≤ 10 mol%) nanocrystalline phosphors were developed by a facile hydrothermal assisted solid-state reaction. X-ray diffraction (XRD) pattern indicated that the prepared samples adopted orthorhombic crystal structures. The agglomeration of uniform nanorods was identified from the FE-SEM analysis of the optimized LWO: 1.5 mol% Dy3+ nanocrystalline phosphors. Additionally, transmission electron microscope, scanning transmission electron microscopy, selected area electron diffraction, and X-ray photoelectron spectroscopy were employed to explore the surface morphology, size, interplanar distance, and chemical composition with valence states of the LWO: 1.5 mol% Dy3+ phosphors, respectively. By exciting with 387 nm, the LWO: Dy3+ emission spectra showed two intense peaks at 476 nm (4F9/2→6H15/2) and 571 nm (4F9/2→6H13/2) and a shoulder peak at 659 nm (4F9/2→6H11/2). Optimum emission intensity was achieved for 1.5 mol% Dy3+ in the LWO host lattice. The luminescence quenching beyond 1.5 mol% Dy3+ is attributed to the dipole-dipole interactions when the Dy3+ (donor) and Dy3+ (acceptor) ions are at a critical distance of 58.53 Å. Photometric studies were conducted to evaluate the performance and practical applicability of the phosphors. The CIE chromaticity diagram suggests that the LWO: 1.5 mol% Dy3+ nanophosphor conspicuously exhibits cool white light. Therefore, this material could be a promising and potential white light-emitting nanocrystalline phosphor material for white light emitting diodes (LEDs) under near-UV excitation. In addition, the toxicity of the optimized nanophosphor in normal WI-38 lung fibroblast cells and MCF-7 breast cancer cells was examined. Surprisingly, LWO: 1.5 mol% Dy3+ nanophosphor was found to be non-cytotoxic to normal cells, but extremely toxic to cancer cells. Therefore, the nanophosphor materials can be considered potential candidates for biomedical applications, particularly for cancer treatment.

Clinical efficacy of universal adhesives for the restoration of noncarious cervical lesions: A randomized clinical trial.

INTRODUCTION: The efficacy of an adhesive agent is an important aspect in restoring noncarious cervical lesion (NCCL) as studies have proved that compromise in adhesive agent results in reduced bond strength. The purpose of this prospective randomized double-blind clinical trial was to evaluate the efficacy of the newly formulated "universal" dental adhesive in the restoration of NCCLs in permanent dentition using either a self-etch or a selective-etch approach. MATERIALS AND METHODS: The study was done following the consolidated standards of reporting trials. 100 NCCLs randomly divided into 2 groups were restored using G-Premio Bond adhesive and Genial flowable composite in selective etch mode and self-etch mode. Restorations were evaluated at 1 week, 6 months, and 12 months using modified US Public Health Service criteria for marginal staining, fracture, and postoperative sensitivity. Statistical analysis was performed using appropriate tests. RESULTS: Recall rates were 100%, 98%, and 78% at the evaluation time. The result showed that neither the self-etch nor the selective etch mode had significant difference in ALPHA/BRAVO/CHARLIE scores (P > 0.05). Percentage-wise comparison showed less changes reported in the selective etch group compared to self-etch group. CONCLUSION: It was concluded that there was no statistical significance between the groups for the parameters evaluated, but selective etch performed better than self-etch group.

Unravelling the process of energy transfer and color tuning from warm to cool white light emission in (Tb3+/Sm3+): lithium borate glasses.

A set of individually and co-doped (Tb3++Sm3+): lithium borate glasses were synthesized by melt quenching. Photoluminescence properties were analyzed by excitation, emission, and decay dynamics. 1.5 mol% Sm3+ glass displayed an intense orange emission at 603 nm (G5/24→H7/26) under 403 nm excitation. Interestingly, Sm3+ emission was remarkably embellished by the inclusion of Tb3+ ions owing to energy transfer from Tb3+ to Sm3+. Chromaticity coordinates and correlated color temperatures were tuned from a warm orange to a cool white region in Sm3+ and (Tb3++Sm3+): glasses, respectively. These studies suggest that (Tb3++Sm3+): lithium borate glasses are favorable candidates for white light emitting diode applications.

Investigation of Upconversion Photoluminescence of Yb3+/Er3+:NaLaMgWO6 Noncytotoxic Double-Perovskite Nanophosphors.

Bright fluorescent rare-earth-ion-doped upconversion nanomaterials are attractive choices for photonic devices. A remarkable green upconversion emission has been obtained by the sensitizing effect of Yb3+ in a Yb3+/Er3+:NaLaMgWO6 (NLMWO) nanophosphor under near-infrared (NIR) excitation. A citrate sol-gel method was employed to synthesize the nanophosphor samples. The lack of a secondary phase in the X-ray diffraction pattern confirms that the Er3+ and Yb3+ ions are incorporated in the ordered double-perovskite structure. Surface analysis and particle evaluation are performed by field-emission scanning electron microscopy and transmission electron microscopy analysis. Upconversion and downconversion emission performances were systematically studied by varying the dopant concentrations. A strong upconversion green emission can be observed with the naked eye, and it resembles the upconversion spectra of Er3+-doped phosphors. Remarkably, because of an energy-transfer process, the green upconversion emission can be converted into a strong red emission by codoping with Yb3+ ions. We observed the color tuning effect from green to red, which can be controlled by varying the Yb3+ concentration in the codoped phosphors during NIR excitation. A systematic investigation of the upconversion mechanism from Yb3+ to Er3+ doubly doped NLMWO nanocrystals is demonstrated. The upconversion mechanism was evaluated only by varying the excitation power of the laser as well. A strong NIR emission at 1.57 µm corresponding to Er3+ can be significantly enhanced by increasing the codoping concentration of Yb3+ ions. The energy migration pathway is accurately presented. The Commission internationale de l'éclairage color coordinates were analyzed for singly and doubly doped nanophosphors. The cytotoxicity of the codoped nanophosphor system was evaluated using WI-38 cell lines. This optimized codoped nanophosphor material is noncytotoxic; thus, it can be useful for in vitro studies in biological studies. On the basis of the obtained results, the NLMWO:Yb3+/Er3+ nanophosphors can be a promising choice for novel upconversion photonic applications.

A comparative evaluation of antimicrobial efficacy and flow characteristics of two epoxy resin-based sealers-AH plus and Perma Evolution: An in vitro study.

AIM OF THE STUDY: Bacteria that persist at the time of obturation increase the possibility of persistent apical periodontitis. An ideal sealer should be able to kill these remaining bacteria that are present on the dentinal walls as well as inside the dentinal tubules. This could be possible if a sealer has antimicrobial properties with optimum flow characteristics. Hence, the aim of this in vitro study was to assess the antimicrobial efficacy of epoxy resin-based sealer: AH Plus and Perma Evolution against Enterococcus faecalis on the 1st, 3rd, 5th, and 7th day and also to compare the flow characteristics of both epoxy resin-based sealers. MATERIALS AND METHODS: E. faecalis ATCC 35550 strain was used to assess the antibacterial efficacy of sealers by agar-diffusion test (ADT) and direct-contact test (DCT). Flow characteristics of sealers were measured according to the ADA specification no. 57. RESULTS: In ADT, Perma Evolution sealer showed larger zone of inhibition than AH plus on the 1st, 3rd, 5th, and 7th day, and in DCT, both sealers were equally effective in inhibiting E. faecalis growth on the 1st, 3rd, 5th, and 7th day. Flow test showed no significant difference between Perma Evolution and AH Plus sealer. CONCLUSION: Both the tested sealers were equally effective against E. faecalis up to 7 days of incubation period. Considering flow properties, both the tested sealers showed optimum flow as per the ADA specification no. 57.

Traumatic myositis ossificans of the masseter muscle: a case report with conventional and advanced imaging features.

Myositis ossificans of the head and neck is a rare heterotopic, nonneoplastic bone formation within a muscle. Traumatic myositis ossificans (TMO), also known as myositis ossificans circumscripta, is the most common form, resulting in muscle ossification after trauma or hematoma. This article presents a case of TMO in the left masseter muscle of a 26-year-old male patient who suffered from epilepsy. The various types of myositis ossificans, its epidemiology, pathogenesis, differential diagnoses, and various treatment modalities are outlined.

Calculation of intraocular lens power using Orbscan II quantitative area topography after corneal refractive surgery.

PURPOSE: To present the prospective application of the Orbscan II central 2-mm total-mean corneal power obtained by quantitative area topography in intraocular lens (IOL) calculation after refractive surgery. METHODS: Calculated and achieved refraction and the difference between them were studied in 77 eyes of 61 patients with previous radial keratotomy (RK), RK and additional surgeries, myopic LASIK, myopic photorefractive keratectomy (PRK), or hyperopic LASIK who underwent phacoemulsification without complications in 3 eye centers. All IOL calculations used the average from the central 2-mm Orbscan II total-mean power of maps centered on the pupil without the use of previous refractive data. Six IOL styles implanted within the bag were used. RESULTS: Using the SRK-T formula, the overall calculated refraction was -0.64+/-0.93 diopters (D). The overall achieved spherical equivalent refraction (-0.52+/-0.79 D; range: -3.12 to 1.25 D; 95% confidence interval [CI]: -0.70/-0.34 D) was +/-0.50 D in 53% of eyes, +/-1.00 D in 78% of eyes, and +/-2.00 D in 99% of eyes. The overall difference between the calculated and achieved refraction (0.12+/-0.93 D, P=.27; range: -2.18 to 2.62 D; 95% CI: 0.09/0.33 D) was +/-0.50 D in 39% of eyes, +/-1.00 D in 77% of eyes, and +/-2.00 D in 96% of eyes. This difference was +/-1.00 D in 77% of eyes with RK (P=.70), 82% of eyes with myopic LASIK (P=.34), and 90% of eyes with myopic PRK (P=.96). In eyes with RK followed by LASIK, a trend toward undercorrection was noted (P=.03). In eyes with hyperopic LASIK, a trend toward overcorrection was noted (P=.005). CONCLUSIONS: In eyes with previous corneal refractive surgery, IOL power calculation can be performed with reasonable accuracy using the Orbscan II central 2-mm total-mean power. This method had better outcomes in eyes with previous RK, myopic LASIK, and myopic PRK than in eyes with hyperopic LASIK or RK with LASIK.

An asymmetric dimer of beta-lactoglobulin in a low humidity crystal form--structural changes that accompany partial dehydration and protein action.

Dimeric lactoglobulin molecules exist in the open conformation at basic pH, whereas they exist in the closed conformation at acidic pH, after undergoing the Tanford transition around neutral pH. Orthorhombic crystals consisting of molecules in the open conformation, grown close to neutral pH, undergo a water-mediated transformation when the relative humidity around the crystals is reduced. The two subunits in the dimer are related by a crystallographic twofold axis in the native crystals while the dimer is asymmetric in the low humidity form. Interestingly, one of the subunits in the dimer in the low humidity form is in an open conformation while the other is in a closed conformation. This is the first observation of such an asymmetric dimer. A hydrogen bond between the side chains of Gln35 and Tyr42 exists and the side chain of Glu89 is substantially buried in the closed subunit of the asymmetric unit, as in other structures with molecules in the closed conformation. However, the closure of the EF loop is not complete; its conformation can be described as half-closed. A comparison of different crystal structures of beta-lactoglobulin indicates that the conformation of the loops in the molecule is substantially influenced by other factors such as crystal packing, the pH, and the composition of the medium, while the change in the conformation of the EF loop follows the Tanford transition. The mutual disposition of the two subunits in the low humidity form is halfway between those in the open and closed structures. The present work further demonstrates that structural changes that occur during partial dehydration could mimic those that occur during the action of proteins.

Piperidinium 3-[(4-hydroxy-5-dimethyl-2-oxo-2H-chromen-3-yl)-phenylmethyl]-5,7-dimethyl-2-oxo-2H-chromen-4-olate.

In the title salt, C5H12N+*C29H23O6-, both benzopyran systems are planar. Intermolecular N--H...O hydrogen bonds and a short O--H...O intramolecular hydrogen bond are observed in the structure.

2,4-Bis(o-tolyl)-3-azabicyclo

The crystal structure of the title compound, C(22)H(25)NO, confirms that the bicyclic ring system adopts the chair-chair conformation. The phenyl rings are equatorially disposed with respect to the bicyclic ring. There is a slight deviation from the chair conformation in the case of the cyclohexane ring.