Types Of Cavities Research Articles

Realizing the topological rainbow based on cavity-coupled topological edge state

Topological photonic crystals (PCs) can support topologically protected states of light. These states are immune to backscattering and can be used to construct a variety of optical devices. One promising application of topological PCs is the formation of a topological rainbow. We propose a method for realizing a topological rainbow based on cavity-coupled topological edge state (TES) in a topological photonic crystal waveguide (TPCW). This is a new type of cavity coupled TPCW, in which the cavity is located inside the waveguide at the interface between two topologically distinct PCs. We demonstrated that by varying the cavity length in the TPCW, the separation of different frequencies of topological states can be controlled. Moreover, we showed that the topological rainbow is unaffected by the cavity shape inside the TPCW. This method is more robust and versatile than previous methods, as it is unaffected by the cavity shape. This makes it possible to create topological rainbow in a wide variety of high-performance devices. For example, it could be used to build topological rainbow in integrated circuits, which would be very difficult if the cavity shape was precisely controlled. We hope our findings will inspire further research in this area and lead to the development of new and innovative optical devices.

Impact of contracted endodontic access cavity designs on root canal disinfection using diode laser: An “In-Vitro” Study

Introduction: New approaches for minimal invasive endodontic access cavity designs had been introduced for preserving the structural integrity of the offending tooth. Diode laser has been now widely used in root canal disinfection and showing highly promising results. Aim: to evaluate the impact of contracted endodontic access cavity designs on root canal disinfection using diode laser. Materials and Methods: Fifty-four intact freshly extracted human mandibular first molars were selected for the use in this study. Only the mesial roots of the selected samples were included in this study. Samples were randomly divided into three equal groups (n=18) according to the type of access cavity performed. Group (1): conventional access cavities, Group (2): Ninja access cavities, and Group (3): truss access cavities. Isolates of Enterococcus Faecalis (E.Fecacalis) were introduced in the root canals of the mesial roots of the selected samples. Samples were further sub-divided into two equal sub-groups (n=9) according to the disinfection method. Sub-group (a): Diode laser disinfection, and Sub-group (b): NaOCl 2.5% followed by EDTA 17% irrigation. Bacterial evaluation was performed using confocal laser scanning electron microscope. Results: The results showed that using Diode laser disinfection have shown higher bacterial reduction in comparison to NaOCl irrigation, but with no statistically significant difference. For access cavity designs, regardless of the type of disinfection used, conventional access cavities have shown the highest bacterial reduction, with the least bacterial reduction with Ninja access cavities. Conclusion: Contracted endodontic access cavities did not offer any advantages in comparison with the conventional endodontic access cavities regarding bacterial reduction. Diode laser can be used as an effective adjunct tool in root canal disinfection.

Perioperative complications of using freezing nitrogen ethanol composite to treat bone tumors: Clinical experience from a single center.

The cryoablation efficacy of semisolid freezing nitrogen ethanol composite (FNEC) has been demonstrated. We aimed to investigate the feasibility of adjuvant FNEC-assisted cryoablation in different bone cavity types by assessing the perioperative complication rates. The medical charts of patients who received intraoperative adjuvant cryoablation using semisolid FNEC for bone tumors from December 2013 to January 2018 were reviewed. The bone cavities were categorized into three types according to liquid spill potential (type 1, able to hold liquid without limb manipulation; type 2, required extensive limb manipulation to retain liquid; type 3, unable to retain liquid). The overall complication rate and the complication rates stratified by bone cavity type were determined. Among the 76 patients, 30.3%, 57.9%, and 11.8% had type 1, 2, and 3 bone cavities, respectively. The mean follow-up time for perioperative complications was 43.5 ± 24.1 days. Five patients experienced complications, including two cases of skin damage, two cases of skin infection, and one case of fracture, yielding an overall perioperative complication rate of 6.4%. All cases of skin damage and skin infection were superficial and manageable by oral antibiotics. The patient with a pathologic fracture recovered well after being treated with open reduction and plate fixation. No neuropraxia was noted within the first few days postsurgery in any patient. The complication rates in type 1, 2, and 3 bone cavities were 13%, 4.6%, and 0%, respectively. All bone cavity types had a low incidence of perioperative complications after treatment with adjuvant FNEC-assisted cryoablation. Semisolid FNEC-assisted cryoablation is a feasible alternative to overcome the liquid spill potential in bone cavities resulting from tumor resection and intralesional curettage.

Some features of electrostatics of uncharged thin-walled cylindrical and conical conductors

It is shown that for thin-walled uncharged cylindrical and conical conductors in the field of a point charge, there is an electrostatic “repulsion effect” previously predicted for conductors with a non-through cavity. Axial symmetry of the cavity is not necessary for the manifestation of the effect. This proves the possibility of a “repulsion effect” for conductors with different types of cavities.

Morphometric analysis of cavitas glenoidalis with multidedector CT

The glenoid cavity is a sliced egg-shaped joint surface located on the lateral margin of the scapula to form the shoulder joint. Recognition of variations in shape and dimensions of the glenoid cavity is important for a better comprehension of joint-associated diseases, especially in total shoulder arthroplasty procedures. The aim of this study was to perform morphometric measurements on the glenoid cavity. Glenoid cavities of 391 individuals (197 males [50.4%], 194 females [49.6%]) were reviewed by using Multi-detector Computed Tomography. The maximum length and maximum width of glenoid cavities, as well as the width, depth and circumference at the notch level were measured, and the index value was calculated. The glenoid cavity shapes were typed as pear, inverted comma and oval type. Furthermore, the metric values that provide the best differentiation between genders were identified through ROC analysis. The pear glenoid cavity type was detected in 53.2%, inverted comma type was detected in 28.4%, and oval type was detected in 18.4% of cases. In all of our morphometric measurements, male values were higher than female values, and there was significant difference between them. Results of ROC analysis revealed significant measurements for the maximum length and maximum width measurements of the glenoid for gender determination. Morphometric information of the glenoid cavity can be useful in order to increase clinical success in case of Bankart lesion, rotator cuff disease, and osteochondral defect. Recognition of different shapes and dimensions of the glenoid cavity is essential for the design of the glenoid component, especially for total shoulder arthroplasty procedure. We believe that the data obtained in our study would be useful for prosthesis designers and orthopaedic surgeons.

Impact of nano-scale cavities on hydrogen storage and retention in yttrium hydride

In situ synchrotron high-energy x-ray diffraction experiments and detailed transmission electron microscopy (TEM) characterization were conducted on as-fabricated and neutron-irradiated yttrium hydrides. The high-resolution synchrotron x-ray diffraction revealed minor α yttrium and major δ yttrium hydride phases in all specimens. Specimens were subject to heat treatments (heating-cooling cycles), and the intensity of α yttrium partially and completely disappeared in as-fabricated and neutron-irradiated specimens, respectively. The disappearance of α yttrium was unforeseen because hydrogen was expected to leave δ phase, causing an increase in α yttrium diffraction peak intensity. This observation indicated a surplus of hydrogen in the specimens where it was odd for hydride-forming early transition metal elements. The subsequent through-focus TEM characterization discovered nanometric cavities in both as-fabricated and neutron-irradiated yttrium hydride specimens for the first time. Two types of cavities were identified as fabrication-caused and irradiation-induced. The fabrication-caused cavities were associated with regions having linear deformation features, interfaces, and inclusions. The irradiation-induced cavities were observed as being formed isolated in the yttrium hydride phase. The presence of such nanometric cavities was considered as potential hydrogen storage pockets where the overall hydrogen storing capacity of yttrium hydride would be enhanced.

Morphometric Parameters of the Sphenoid Sinus with Different Types of Pneumatization and Nasal Cavity in Mature Men

The aim of the study was to determine the availability of the relationship between the morphometric dimensions of the sphenoid sinus and the nasal cavity in mature men with different types of pneumatization of sinus shpenoidalis.Material and methods. A morphometric study of 25 skull cuts of mature men with a wound type of sinus pneumatization performed in the median plane was carried out. A morphometric template and ImageJ version 1.52u program were used to determine the height and longitudinal dimensions of the sinus, the length of the Zuckerkandl line, the thickness of the sinus walls along it, as well as a number of height and longitudinal dimensions of structures forming the walls of the nasal cavity. The Statistica 6.0 program was used for statistical processing.Results. Comparing the minimum height of the sphenoid sinus and the longitudinal dimensions of the middle nasal concha along the attachment line and along the free edge, the Spearman correlation coefficient has values of 0,57 and 0,44, respectively; when comparing the longitudinal dimensions of the sinus with the same indicators - 0,53 / 0,56 (for the maximum length of the sinus) and 0,46 / 0,45 (for the minimum); for the Zuckerkandl line, carried out to the anterior and posterior walls of the sinus, and the height of the piriform aperture - 0,73 and 0,63, respectively.Conclusion. Basically, regardless of the type of pneumatization of the sinus, its dimensions are not interrelated with the longitudinal and height dimensions of the nasal cavity. A significant moderate positive correlation is observed between the size of the sinus and the length of the middle nasal concha. This implies an interconnected increase in these sizes and, as a result, obtaining the greatest room for maneuver when conducting sinus probing along the Zuckerkandl line in the case of their maximum values.

Comparative analysis of the heavy-weight floor impact noises using various shapes of EVA resilient materials

Social issues concerning the floor impact noises are increasing as apartments are being increased in Korea. The present study aims to improve the floor impact noises using various shapes of EVA resilient materials in composite floor structures. In order to this, three different shapes of EVA resilient materials were used including flat plate type, deck plate type, and cavity type of EVA. boards. All the composite structure consisted of PP panel, PET sound absorption materials and EVA resilient materials with a total depth of 40mm. Also, each shape of EVA has two different types according to the use of foothold of EVA materials. For the mount type of structure, the used numbers of EVA foothold was 25, 56, and 41 per 1 m2 of area. All the floor impact noise measurements were done at the recognized testing authority using impact ball as the standard heavy-weight floor impact sound source. The values of L’i, Fmax, and AW were deduced from every measurements. As a result, regardless of the EVA shapes, better performances were drawn when EVA footholds were used, i. e., mount type. It was shown that the average L’i, Fmax, and AW value of mount types was 41–42dB while average value of 47–48 dB for deck plate type. 50–55 dB for flat plate and cavity type were measured. It can be recognized that the good performance of mount type EVA materials is caused by the air layer gap around the EVA footholds as well as the low dynamic elastic modulus of EVA.

Direct Comparison of the Acoustic Stability of ECDLs with Different Types of an External Cavity

Direct Comparison of the Acoustic Stability of ECDLs with Different Types of an External Cavity

Model for core catcher ablation and cavity shape in the film regime

During core meltdown in a nuclear reactor the corium may propagates toward the lower head and hit the vessel or structural elements as a coherent liquid jet. This could occur for instance in sodium fast reactors (SFR) if discharge tubes and an in-vessel core-catcher are used as mitigation devices. This can result in the ablation of the core-catcher and potential loss of its integrity. During ablation, a cavity is formed within the solid. Therefore the ablation of a solid structure by a liquid jet is studied here, with a focus on the cavity shape to improve future core-catcher designs. During the cavity formation, liquid flows over the cavity being formed as a liquid film in the film ablation regime, and ultimately results in the formation of a liquid pool. In the film ablation regime, two types of cavity shapes have been identified previously. To describe the process of the cavity formation, a mathematical model valid in this film ablation regime is here proposed which links the local melting rate to the local curvature of the cavity. It is applied with two sets of assumptions applicable to the two types of cavity previously identified. For the first assumption set, the heat transfer coefficient varies along the liquid/solid interface while the liquid temperature is held constant, it is representative of laminar boundary layer growth in laminar film. For the second assumption set, the heat transfer coefficient is held constant while the temperature varies along the liquid/solid interface, this is consistent with a turbulent liquid film. The two modeling approaches are compared with experimental data acquired from the HAnSoLO experimental setup. Numerical predictions show promising agreements with experimental observations, particularly for the laminar boundary layer growth zone of the cavity.

Building brick wall thermal management optimization and temperature control based on phase change materials integration. Case study of the city of Bechar, Algeria

Energy is a critical component of modern human life, and life without energy-consuming sectors is unthinkable for twenty-first-century humans. The building sector is a significant consumer of energy. A significant portion of human energy consumption is used to maintain comfortable building conditions. This work investigates three types of brick cavities (square, polygon, and circle cavities) filled with various phase change materials (PCMs). PCMs include RT24, RT42, n-Eicosane, and Capric acid. In Algerias hot climate, the effects of PCM type and cavity forms on the thermal performance of brick walls are discussed. In addition, an energy consumption comparison was performed between the new wall brick and the traditional brick. According to the findings, the utilization of PCM within the brick wall leads to a decrease in the indoor heat transfer and generates an indoor wall temperature more in line with the desired indoor air temperature. Furthermore, when square cavities are filled with capric acid as PCM, the outcome is a maximum temperature of 27.8 °C. Moreover, it leads to a reduction of 67.84 % in peak indoor heat flux and a decrease of 61.8 % in energy consumption.

(Invited) Dynamics of Light-Matter Interactions in Plasmonic Optical Cavities for Characterizing Nanostructures Relevant to Energy Conversion and Photocatalysis

Optical cavities are an established means to increase light-matter interactions with a wide range molecules, nanostructures and bulk materials. The use of an optical cavity to increase the likelihood of photon absorption by a material has clear potential for being of value for optical energy conversion and photocatalysis. Furthermore, optical cavities can significantly alter excited state dynamics due to the potential for Purcell effects that increase radiative rates of emission of a given material, molecule, or nanostructure. These dynamic changes can serve as a sensing mechanism of cavity impact to photoprocesses, making characterization tools such as transient absorption and time-resolved emission measurements an effective means to probe the degree of light-matter coupling. Taken a step further, these characterization tools can help establish the degree of light-matter coupling necessary to control excited state lifetimes for a particular purpose or application. Here, we explore the dynamics of nanostructured systems coupled to, or made out of, plasmonic materials. Importantly, plasmonic structures are well-known to serve as a type of optical cavity, and though plasmonic cavities are lossier than their dielectric counterparts, they can also confine light to a small mode volume which is very helpful for increasing photonic interactions with nanostructures. The focus of this talk is on materials and nanostructures of interest for solar energy conversion or photocatalysis, such plasmonic nanoparticles and semiconducting nanoparticles, which are interacting with or functioning as, a plasmonic cavity. The plasmonic cavity can be as simple as a thin metal film that supports a propagating surface plasmon polariton (SPP). We also explore refractory plasmonic systems due to their potential durability and reduced likelihood of melting under optical illumination as compared to noble metal nanostructures. The dynamics of nanostructure photoprocesses as a function of photon energy relative to the cavity resonance is explored in detail and impact on applications is described. Work performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

Characteristics of Chaotic Weak Reflection in Carbonate Fracture-Cavity Reservoirs: A Case Study of Ordovician Reservoirs in Block 10 of the Tahe Oilfield, Tarim Basin, China.

The identification of carbonate reservoirs is a critical task in oil and gas exploration. Chaotic weak reflection is an important type of reflection characteristic in carbonate reservoirs. Widespread distribution of chaotic weak reflection has been observed in the Ordovician Yijianfang Formation in the Tahe area. However, there is still a lack of systematic research on the distribution, characteristics, reservoir space, and reservoir types of chaotic weak reflection in the Tahe area. To address this issue, this study conducted a comprehensive analysis of multiscale data and found that chaotic weak reflections are distributed within 100 ms below the top interface of the Middle Ordovician. Seismic profiles exhibit a "string of pearls" with a "tail" or "pearl-like" widening feature. On well logs, all three porosity curves exhibit localized peaks, with increases in acoustic (AC) and compensated neutron (CNL) and decreases in density (DEN), while the deep and shallow lateral resistivity (RD, RS) curves show positive amplitude differences. In the FMI, they are represented by dark sinusoidal curves and dark small patches. Based on these response characteristics, two types of reservoir spaces are identified for chaotic weak reflections: high-angle vertical fractures and caves with heights less than 7 m, which can form independent reservoirs or fracture-cavity complexes. Three types of reservoirs are distinguished: fracture, cavity, and cavity-fracture types.

Pore-scale modeling of thermal-hydro-mechanical-chemical coupled rock dissolution and fracturing process

Acid fracturing can effectively improve the connectivity inside underground reservoirs, which is of significance for geothermal exploitation and geological carbon sequestration. It involves a complex thermal-hydro-mechanical-chemical (THMC) coupled process. This work first develops a pore-scale THMC coupled model combining the lattice Boltzmann method (LBM) and the discrete element method (DEM) to describe the acid fracturing process, particularly covering chemical damage, rock dissolution, and solute transport. A chemical damage variable based on the cohesive bond is proposed to characterize the alteration of mechanical parameters caused by local rock dissolution. The change of fluid pathway due to rock dissolution is handled by the lattice Boltzmann solute transport model combined with the volume of pixel method. Based on the proposed model, the influence of injection pressure and Damkohler number (Da) on the THMC coupled rock dissolution and fracturing process is analyzed. Results indicate three types according to dissolution morphologies, i.e., permeation, cavity, and permeation-cavity. The first and second types are related to the reaction-controlled and diffusion-controlled processes, respectively. Particularly, the permeation-cavity type occurs at conditions with high injection pressure and high Da and is the combination of the first two types, where the dissolution around the main fracture presents the cavity type but converts into the permeation type around secondary fractures. Additionally, the evolution patterns of reactive surface area and dissolution rate with time differ significantly with rock dissolution types. In particular, for the permeation type, the aperture of fracture far away from the injection hole could be larger than that near the injection hole under the THMC coupling, which is quite different from HM and THM coupling.

Cavity-breeding birds create specific microhabitats for diverse arthropod communities in boreal forests

The nests of secondary cavity-nesters located in tree cavities may form specific microhabitats of conservation importance due to their limited accessibility and availability. Species-specific nesting materials in nests of different secondary cavity-nesters may furthermore provide very different microhabitats for arthropods. The potential differences in arthropod communities inhabiting nests of different bird species in excavated cavities or nest boxes have, however, rarely been studied despite their relevance for conservation. Here we investigated the diversity and composition of arthropod communities in these different cavity types and bird species’ nests in managed boreal forests. We identified morphologically and by DNA-metabarcoding arthropods in nest materials that were collected in and compared between (i) woodpecker-size cavities from seven different combinations of cavity type (nest box or excavated cavity), tree species (aspen or pine) and accumulation history of nest materials (single-season cleaned or uncleaned nest boxes that accumulated nests of passerines or an owl species); and (ii) nests of two different passerine species in small nest boxes. We identified 64 arthropod taxa in ten orders, from which Diptera, Coleoptera, Siphonaptera, and Lepidoptera were the most abundant. Shannon diversity index was similar among the cavity-nest-type combinations, but taxa richness was the highest in the owl nests. The arthropod communities (especially Histeridae beetles) deviated most from the other types of nests in owl and aspen cavity nests with more advanced decomposition of nest material (soil or wet environment related taxa). The differences in arthropod communities between the different nest types point out the importance of the ecological chain “tree cavities—bird nests—arthropod communities”.

Study on the Restoration of Class II Carious Cavities by Virtual Methods: Simulation of Mechanical Behavior.

The restoration of class II cavities is predominantly carried out with composite materials. Due to the high failure rate in restoring this type of cavity, composite materials with much-improved properties and new application techniques have been promoted. The study aimed to analyze the mechanical behavior of several topical composite materials (nanocomposites, nanohybrids and ormocer) using different application techniques. In a lower second molar, a class II occlusal cavity was prepared. As filling materials, we used the following combinations: Admira Fusion and Admira Fusion Flow, Grandio and Grandio Flow, Filtek Supreme XT and Filtek Supreme Flow. These were applied using a snow plow, injection molded and Bichacho techniques. Three-dimensional scanning of the molar with the prepared cavity was performed, and then scanning of each layer of added composite material was performed, obtaining three-dimensional models. The virtual molar models were analyzed with software specific to the finite element analysis method, where their physical-mechanical properties were entered and assigned to the components of the virtual molar. Simulations at high forces specific to bruxism were then carried out and analyzed, and compared. The values of displacements and strain, for all six analyzed situations, are relatively small (range from 5.25 × 10-6-3.21 × 10-5 for displacement, 6.22 × 10-3-4.34 × 10-3 for strain), which validates all three methods and the materials used. As far as the stress values are concerned, they are similar for all methods (250-300 MPa), except for the snow plow and injection-molded techniques using Grandio and Grandio Flow composites, where the maximum von Mises stress value was more than double (approximately 700 MPa). When using the combination of Grandio and Grandio Flow materials, the 1 mm thickness of the fluid composite layer was found to have a major influence on occlusal forces damping as opposed to 0.5 mm. Therefore, the Bichacho technique is indicated at the expense of the snow plow and injection-molded techniques. The composite materials used by us in this study are state-of-the-art, with clear indications for restoring cavities resulting from the treatment of carious lesions. However, their association and application technique in the case of Class II cavities is of clinical importance for resistance to masticatory forces.

Biomechanical Properties of Maxillary Second Molar with Different Endodontic Cavity Designs - A Finite Element Analysis.

To evaluate the biomechanical properties of maxillary second molars with three different cavity designs - Traditional, Conservative, and Extended - endodontic cavities using the finite element analysis method. Three finite element models of a maxillary second molar with three different types of endodontic cavities were designed and restored. Each model was subjected to three different force loads directed at the occlusal surface. The stress distribution patterns and the maximum von Mises (VM) stresses were calculated and compared. Vertical force of multipoint load on the occlusal surface and lateral forces to the palatal cusp showed the maximum stress values in the extensive cavity design, followed by the traditional cavity design and then the conservative cavity design. The VM stress distribution in the conservative endodontic cavity was minimal when compared to other access cavity designs.

Numerical investigation of influence of near-surface lateral heterogeneities on propagation of Rayleigh waves

Recent research on earthquake disasters has provided evidence that Rayleigh waves play a crucial role in causing damage to both underground and surface structures during earthquakes. In this study, we utilize the finite difference method to investigate the impact of the interaction between Rayleigh waves and near-surface heterogeneities on seismic ground response. Specifically, we analyze the effects of different types of cavities (vacuum cavity, water-filled cavity, and soft-soil-filled cavity) as well as granite boulders on the propagation of Rayleigh waves. Furthermore, we examine how the buried depth and size of the heterogeneous structure, as well as the distance from the center of the structure, influence the amplitude and frequency spectrum of Rayleigh waves. Our numerical results reveal that the presence of cavities leads to larger amplitudes of Rayleigh waves compared to the free field, with the amplification effects becoming more pronounced as the cavities become shallower. Although the amplitude of Rayleigh waves generally decreases with increasing offset, the complex interaction between Rayleigh waves and the heterogeneous structure causes significantly smaller amplitudes on the far offset side of the cavity, while the near offset side exhibits significant amplification phenomena. Moreover, the characteristics of the Rayleigh-waves field vary depending on the filling material inside the cavities. For instance, the wall of a water-filled cavity clearly shows the presence of Scholte waves, whereas a soft-soil-filled cavity exhibits an energy traps phenomenon. Additionally, the conversion phenomena of Rayleigh waves generated by these two types of cavities are characterized by strong energy and smooth continuity. On the other hand, granite boulders have a relatively minor influence on Rayleigh wave propagation at the far-source side, except for partial scattering of waves. However, at the near-source side, significant amplitude amplification occurs in the vicinity of granite boulders, particularly for the high-frequency radial component. Therefore, considering the intricate interaction between Rayleigh waves and near-surface lateral heterogeneities, the findings of this study can serve as valuable guidance for seismic micro-zonation and the design of observation systems using the high-frequency surface-wave method.

Extra-pair paternity, breeding density, and synchrony in natural cavities versus nestboxes in two passerine birds.

Most of what is known about extra-pair paternity in hole-nesting birds derives from studies using artificial nesting sites, such as nestboxes. However, it has rarely been investigated whether inference drawn from breeding events taking place in nestboxes matches what would be observed under natural conditions, that is, in natural cavities. We here report on a variation in promiscuity in blue tits and great tits nesting in natural cavities and nestboxes in an urban forest in Warsaw, Poland. Specifically, we tested whether local breeding density, local breeding synchrony, and extra-pair paternity (inferred from SNP data generated with a high-throughput genotyping by sequencing method) differed between birds nesting in natural cavities and nestboxes. In both blue tits and great tits, the frequency of extra-pair paternity was similar between the two cavity types. In blue tits, we observed shorter nearest neighbor distance, higher neighbor density, and higher synchronous neighbor density (i.e., density of fertile females) in nestboxes relative to natural cavities. No such pattern was found in great tits. Moreover, we detected a positive relationship between the proportion of extra-pair offspring in the nest and neighbor density around the nest in blue tits. Our results revealed that the provisioning of nestboxes did not change rates of extra-pair paternity, suggesting that conclusions drawn from nestbox studies might adequately represent the natural variation in extra-pair matings in some species or sites. However, the observed differences in spatiotemporal components of breeding dynamics highlight the fact that these parameters should be carefully considered when comparing mating behavior across studies and/or sites.

Effect of Traditional and Conservative Endodontic Access Cavities on Instrumentation Efficacy of Two Different Ni–Ti Systems: A Micro-CT Study

This study aims to compare the shaping efficiency of the nickel–titanium instrument systems, One Reci and ProTaper Ultimate, using micro-CT (micro-computed tomography) in traditional and conservative endodontic access cavities. The experimental groups were formed according to the type of access cavity and Ni–Ti file system to be used. Sixty mandibular molar teeth were randomly divided into two main groups, the conservative access cavity (CAC) group and the traditional access cavity (TAC) group, and randomly divided into two subgroups according to the file system. The groups were compared with a two-way ANOVA analysis in terms of volume change, surface area, non-instrumented area transportation, and thickness of the dentin in the danger zone area after root canal preparation. The groups showed no statistically significant differences in terms of volume change, surface area, or the thickness of the dentin in the danger zone area after root canal preparation (p > 0.05). However, in the percentage of non-instrumented areas post-instrumentation between groups, the percentage of non-instrumented areas was statistically higher in specimens with CAC compared to TAC (p < 0.05). Canal transportation was higher in CAC at all distances from the apical region (p < 0.05). Within the limitations of this study, CAC can also be used with some precautions as an alternative to TAC.