Evaluation of the Root Canal Centering Ratio and Canal Transportation Associated With Three Rotary File Systems Using Cone Beam Computed Tomography (CBCT) Analysis.

Aim The aim of the present study was to evaluate the in vitro comparative assessment of root canal centering ratio and canal transportation associated with ProTaper Universal (PTU) (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next (PTN) (Dentsply Maillefer, Ballaigues, Switzerland), and ProTaper Gold (PTG) (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA) rotary file systems, with or without glide-path preparation, using cone beam computed tomography (CBCT) analysis. Materials and methods A total of 120 mesial roots of extracted human mandibular first molar teeth were collected and randomly divided into three groups (n = 40) depending on the type of rotary file system used for mesiobuccal root canal instrumentation: Group 1: PTU, Group 2: PTN, and Group 3: PTG rotary file systems. Each group was further divided into two Sub-groups (a and b) with 20 specimens, depending on whether glide-path preparation was performed using the ProGlider (PG) file (Dentsply Maillefer, Ballaigues, Switzerland).

Field Emission Scanning Electron Microscope Analysis of the Marginal Adaptation of Various Root Canal Sealers at the Dentin-Sealer and Sealer-Guttapercha Interfaces at Three Root Canal Levels: An In Vitro Study.

Aims An in vitro evaluation of the marginal adaptation of four root canal sealer variants at the dentin-sealer and sealer gutta-percha interfaces in the coronal, middle, and apical thirds of root canals was conducted using field emission scanning electron microscope (FESEM) analysis.  Materials and methods In total, 80 extracted human mandibular premolar teeth were used in this study. All teeth were decoronated to standardize the root length to 14 mm.

Cell-type-specific cholinergic control of granular retrosplenial cortex with implications for angular velocity coding across brain states.

Cholinergic receptor activation enables the persistent firing of cortical pyramidal neurons, providing a key cellular basis for theories of spatial navigation involving working memory, path integration, and head direction encoding. The granular retrosplenial cortex (RSG) is important for spatially-guided behaviors, but how acetylcholine impacts RSG neurons is unknown. Here, we show that a transcriptomically, morphologically, and biophysically distinct RSG cell-type - the low-rheobase (LR) neuron - has a very distinct expression profile of cholinergic muscarinic receptors compared to all other neighboring excitatory neuronal subtypes.

An evaluation of Icon resin infiltrant penetration into demineralized enamel lesions using an indirect staining technique with confocal laser scanning microscope analysis in dual fluorescence mode.

Context: White spot lesion is the first clinical sign of a caries lesion and represents mineral loss from the enamel subsurface.

Aim: The aim of this study was to evaluate the penetration depth (PD) of Icon resin infiltrant into artificially demineralized enamel lesions using confocal laser scanning microscope (CLSM) analysis in dual fluorescence mode.

Settings And Designs: The design of the study was an study.

In-Vitro Evaluation of Dental Adhesive Bond Strength With Diode Laser Irradiation Before Photopolymerization.

Aim: In-vitro evaluation of shear bond strength, mode of failure, and adaptation of fifth-generation (etch-and-rinse), seventh-generation,and eighth-generation self-etch dental adhesives to human dentin with or without diode-laser irradiation before photopolymerization.

Materials And Methods: Seventy-two extracted human maxillary premolar teeth were collected. The buccal and lingual surfaces of teeth were grounded until dentin was exposed.

Running speed and REM sleep control two distinct modes of rapid interhemispheric communication.

Rhythmic gamma-band communication within and across cortical hemispheres is critical for optimal perception, navigation, and memory. Here, using multisite recordings in both rats and mice, we show that even faster ∼140 Hz rhythms are robustly anti-phase across cortical hemispheres, visually resembling splines, the interlocking teeth on mechanical gears. Splines are strongest in superficial granular retrosplenial cortex, a region important for spatial navigation and memory.

Instantaneous amplitude and shape of postrhinal theta oscillations differentially encode running speed.

Hippocampal theta oscillations have a temporally asymmetric waveform shape, but it is not known if this theta asymmetry extends to all other cortical regions involved in spatial navigation and memory. Here, using both established and improved cycle-by-cycle analysis methods, we show that theta waveforms in the postrhinal cortex are also temporally asymmetric. On average, the falling phase of postrhinal theta cycles lasts longer than the subsequent rising phase.

Variable transmission optical filter based on an actuated origami structure.

A variable transmission thin film for visible light is proposed based on a mechanically actuated origami structure coated with metallic nanoparticles. The transmissivity can be tuned continuously from 0 to >90 for unpolarized incident light. Power is only required for switching and is not necessary to maintain the desired transmittance state.