Apical Part Research Articles

Finite element stress analysis in mandibular molars with apical root resorption and crown destruction after root canal treatment using various materials

Aim: The objective of this study is to analyze the stress distribution of root canal treated teeth under occlusal forces and aid in the selection of appropriate materials for teeth with root tip resorption and crown destruction, using the finite element stress analysis method (FEM). Methods: The study was conducted on two-rooted lower molar teeth, divided into five groups. The root length was 14 mm, the crown length was 7.5 mm, and the total length was 21.5 mm. It was assumed that the distal canals were resorbed by 4 mm. Group 1 consisted of untreated intact teeth. Group 2 involved filling the mesial canals with gutta-percha, filling the apical part of the distal canal with 4 mm Mineral Trioxide Aggregate (MTA), and fabricating the crown using glass fiber post and IPS e.max materials. Group 3 involved filling the mesial canals with gutta-percha, filling the apical part of the distal canal with 4 mm Biodentin, and manufacturing the crown using glass fiber post and IPS e.max materials. Group 4: The canals were filled with MTA, and an IPS e.max endocrown was used. Group 5: The canals were filled with Biodentin and an IPS e.max endocrown was used. The study examined the effect of a 100 Newton force applied in the occlusal direction on dental tissues using finite element stress analysis. Results: The study found that the application of fiber posts resulted in less stress accumulation in tooth tissues compared to endocrown. Conclusion: The use of Biodentin or MTA in endocrown teeth did not affect the stress in tooth tissues caused by applied force. In conclusion, while fiber posts increase durability by reducing stress in root-end resorbed teeth, the effect of Biodentin or MTA on stress resistance in dental tissues is limited. How to cite this article: Duran S, Şirin DA, Topbaş C. Finite element stress analysis in mandibular molars with apical root resorption and crown destruction after root canal treatment using various materials. J Med Dent Invest 2024;5:e240320. https://doi.org/10.5577/jomdi.e240320

ANALYSIS OF THE FORM AND SURFACE OF DENTAL IMPLANTS

The aim of the work – to study the peculiarities of the shape and surface relief of the main types of dental implants. Materials and methods. 12 dental implants used in the medical practice of Ukrainian dental clinics were studied. The study of the shape and surface relief of the implants was carried out using a scanning electron microscope GSM-649 (Japan). Results. All implants in the apical part have the shape of a cone with threads and cutting grooves. The thread with a large profile is located in the apical part of the implant, has an average pitch of turns of 1.1±0.05 mm and a profile height of 0.3±0.02 mm. The thread with a small profile is located in the part of the implant near the neck, has a pitch of 0.4±0.02 mm and a profile height of 0.1±0.02 mm. The thread pitch of implants with a single profile is 0.8±0.05 mm, and the height of the profile is 0.2±0.01 mm. Threads with a triangular profile have a profile angle of 50.0±2.9 degrees. The highest roughness is the surface of the top of the fine profile thread with the height of micro-uniformities from 7.0±2.2 to 36.0±8.3 μm, the smallest roughness with the height of micro-uniformities from 3.0±1.1 to 14.0±6.1 μm have surface areas in the area of the implant neck. Conclusions. 50% of the examined implants were made with two thread profiles: a large one in the apical side and a small one closer to the neck, 50% – with the same thread profile from the apical end to the neck. In most implants, the thread with a small profile is made in the form of annular grooves. The large thread of the implants had a rectangular, rounded and triangular profile with one or two steps. In some implants, as they approach the neck, the shape changes and the height of the thread profile decreases. The shape of the profile of small threads in all implants was close to rounded. The implants had different surface roughness. The highest roughness was recorded on the surface of the top of the small profile thread, and the lowest – in the area without a thread in the area of the implant neck.

A preliminary study of the morphological variation of rhizomes in Zingiber Mill. and its role in taxonomy

The rhizomes of Zingiber are highly diverse and have potential in taxonomy, but their fundamental structure has never been properly understood in connection with an understanding of the sympodial growth form of the whole plant. This study is based on a literature review and on observations of fresh materials of 32 Zingiber species mainly from China, representing all four sections of the genus. An analysis of the sympodial modular growth habit of these plants has recognised that both isomodular and heteromodular growth exist within the genus. The study shows that rhizomes of Zingiber are highly-organised, compound, sympodial structures. By introducing the term rhizome unit, Zingiber rhizomes can be meaningfully described by depicting the morphology of the rhizome units and the relative arrangement of these units to one another. Six morphological attributes of rhizome units (shape, size, direction of growth, colour and number of nodes per rhizome, and length of internodes) and two attributes of their relative arrangement to one another (dorsiventral vs lateral position of rhizome units and the ramification position along the length of rhizome unit) are discussed. A preliminary assessment of variation patterns and the taxonomic value of these characters are presented. Together, these attributes contribute to the overall morphology of rhizomes. The relationship between rhizome structure and the above-ground clumping habit is discussed. The term pseudo-neck is coined to refer to the narrowed basal part that occurs in the rhizome units of some Zingiber species while the thick apical part of rhizome units where the internodes are often shorter than those on the pseudo-neck is called head. Problems with existing terminology for rhizome and plant habit descriptions in Zingiber are highlighted. This study suggests that whether the plane of distichy of leaves is parallel or perpendicular to the rhizome unit, a key character that many previous studies used for subdivision of Zingiberaceae, needs re-assessment, because in Zingiber both states of the character exist. Characters of rhizome morphology of the four sections in Zingiber are discussed, but studies of a larger number of species are needed to better-assess the relevance of these characters to the infrageneric classification of the genus. Schematic illustrations and colour plates of rhizomes from representative species are provided to assist the descriptions and discussions. It is hoped that this preliminary study will facilitate and encourage more comprehensive studies of rhizomes of Zingiber and of other genera within Zingiberaceae. Such work will lead to a better understanding of these structures and help establish a more comprehensive and accurate terminology for them, which in turn will facilitate the taxonomy and identification of the family.

The Evaluation of Enamel Matrix Derivative on the Bone Regenerative Potential of the Dental Implant with Transcrestal Sinus Floor Elevation Approach: A Randomized, Parallel-designed CBCT Study.

The study aimed to evaluate the clinical and radiographic results of simultaneous implant placements using transcrestal sinus floor elevation (TSFE) with and without enamel matrix derivative (EMD) application. Twenty-four patients were randomly assigned into two groups: EMD+TSFE Group was defined as (n=13 patients, 20 implants) TSFE with EMD application, and TSFE Group was defined as (n=11 patients, 20 implants) TSFE without EMD application. The patients recalled at 3- (T3) and 12- (T12) months after surgery. The residual bone height (RBH), implant protrusion length (IPL), peri-implant sinus bone level (SBL), endo-sinus bone gain (ESBG), and implant stability (ISQ) were measured. Multivariable regressions were performed for the groups. The ESBG was 3.72±0.85 mm in the EMD+TSFE group and, was 3.10±0.05 mm in the TSFE group at T3 and there were statistically significant differences. (p<0.05). However, there were no statistically significant differences in ESBG at T12 between the groups. (p>0.05) ISQ values did not show a statistical difference between the groups at T1 and T3, but in the TSFE+EMD group, it showed a statistical increase at T3 in the intra-group evaluation compared to the TSFE group. In this study, it can be mentioned that the use of EMD in TSFE operations is effective in new bone formation in the apical part of the implant during the early healing period, but in the long term, no significant difference was shown between cases in which EMD was used or not in terms of new bone formation and primary and secondary stabilization. The study was submitted at ClinicalTrials.com; the clinical trial number is ###.

Contrasting Tectonomagmatic Conditions for Coexisting Iron Oxide-Apatite Deposits and Porphyry and Skarn Cu ± Au Deposits in the Middle-Lower Yangtze River Metallogenic Belt, China

Abstract Porphyry Cu ± Mo ± Au and iron oxide-apatite (IOA) deposits rarely occur in spatial and temporal proximity in Phanerozoic arc-related settings, and the formation of these mineral deposit types in an evolving arc setting remains poorly understood. Specifically, the roles of magma composition and the tectonic regime remain the subject of some debate. Here, we systematically estimated the P-T-fO2 conditions and H2O-S-Cl contents for dioritic to granodioritic source magmas for porphyry and skarn Cu ± Au (150–135 Ma) and IOA deposits (~130 Ma) that formed in transpressional and transtensional settings in the Middle-Lower Yangtze River metallogenic belt, China. Our estimates show that, compared to IOA deposits, the porphyry- and skarn-related magmas were relatively felsic, cooler, and more hydrous. These geochemical features are consistent with the tectonic transition from subduction to slab rollback of the paleo-Pacific plate in the East Asia continental margin at &amp;lt;135 Ma and concomitant crustal extension and steepening of the regional geothermal gradient. Apatite data reveal that the silicate melts associated with the porphyry and skarn Cu ± Au and IOA deposits had comparable predegassed S concentrations (~0.13 ± 0.06 wt % vs. ~0.16 ± 0.09 wt % on average), but that IOA-related melts contained higher predegassed Cl/H2O ratios (~0.11 ± 0.03 vs. ~0.04 ± 0.03 for porphyry- and skarn-related magmas) that decreased by one order of magnitude after magmatic degassing. Magmatic fO2 estimated using zircon and amphibole, reported in log units relative to the fayalite-magnetite-quartz (FMQ) redox buffer, gradually increased during cooling of the porphyry- and skarn-related magmas (ΔFMQ +0.7 to +2.5) at 950° to 800°C and decreased to ΔFMQ +1 at 700°C owing to fractionation of Fe2+-rich minerals and subsequent S degassing, respectively. In contrast, the magmatic fO2 values for the IOA-related source magmas varied significantly from ΔFMQ –1.5 to ΔFMQ +2.5 but generally show an increasing trend with cooling from 970° to 700°C that probably resulted from variable degrees of evaporite assimilation, fractionation of Fe2+-rich minerals, and Cl degassing. These results are consistent with the hypothesis that Cl enrichment of the IOA-related source magmas played a determinant role in their formation. We propose that the porphyry and skarn Cu ± Au deposits in the Middle-Lower Yangtze River metallogenic belt formed in a transpressional setting in response to paleo-Pacific flat-slab subduction that favored storage and evolution of S-rich hydrous ore-forming magmas at variable crustal levels. A subsequent extensional setting formed due to slab rollback, leading to rapid degassing of Cl-rich IOA-related magmas. For the latter scenario, assimilation of evaporite by mafic to intermediate magmas would lead to an enrichment of Cl in the predegassed magmas and subsequent exsolution of hypersaline magmatic-hydrothermal fluid enriched in Fe as FeCl2. This Fe-rich ore fluid efficiently transported Fe to the apical parts of the magma bodies and overlying extensional normal faults where IOA mineralization was localized. The concomitant loss of S, H2O, and Cu with Cl by volcanic outgassing may have inhibited sulfide mineralization at lower temperatures.

The relationship between sarcomerogenesis and the development of tissue organization of the myocardium in embryonic chicken cardiogenesis

Background. The general basis for understanding how the limited range of sarcomere contraction ensures cardiac output during systole is the analysis of the ontogenetic formation and local features of the development of the myofibrillar structure of cardiomyocytes by comparing the phase states of the myocardium. The purpose of the research is to determine phase and topological features and quantitative ultrastructural characteristics of sarcomerogenesis in cardiomyocytes of chicken embryos. Methods. Embryos of Cobb500 crossbred chickens were studied from the beginning of the 6th day to the 21st day of incubation. Ultrastructural features of contractile cardiomyocytes in different areas of ventricular and atrial myocardium in systole and diastole were studied using transmission electron microscopy. Results. At the 29th stage of development of chicken embryos in diastole, immature sarcomeres had different lengths. The average length of sarcomeres was 1.86±0.09 μm in the left ventricle and 1.91±0.21 μm in the right ventricle. At the 36th stage in the state of diastole, a significant increase in the length of sarcomeres was observed in the compact myocardium of the left ventricle and left atrium, while in the right parts of the heart, the increase in Z-Z distance was less active. In the right units of the heart, sarcomeres with unequal lengths were more often found in the compact myocardium and in the trabeculae. In different areas of the myolamella and trabeculae, the degree of relaxation of sarcomeres during simulation of maximum diastole was not the same. Incomplete relaxation of sarcomeres was noted in the initial and final sections of the muscle plates. In the middle part of the trabeculae, the length of the sarcomeres was significantly longer (1.82±0.04 μm), and in the intermediate (main) part of the muscle plates of the compact ventricular myocardium, the sarcomeres were 10.4% (p&lt;0.05) longer, than in their basis. Conclusion. By the end of prenatal cardiogenesis, the tangential orientation of the Z-discs of myofibrils and the shape of cardiomyocytes in systole was formed and strengthened due to the mutual displacement of neighboring myolamella during the counter-directional rotation of the basal and apical parts of the left ventricle during the shortening of sarcomeres to 1.83±0.04 μm. In the right ventricle and atrial myocardium, systolic contraction did not change the orthogonal orientation of telophragms and intercalated discs when sarcomeres were shortened to 1.79-1.84 μm. In the state of diastole, the orthogonal orientation of Z-discs is characteristic of contractile cardiomyocytes of all chambers when the length of sarcomeres reaches 2.17±0.07 μm in the intermediate part of the myolamella of both ventricles, 2.12±0.13 μm in the middle part of atrial and ventricular trabeculae, 2.02±0.10 μm at the base of trabeculae of all chambers and muscle plates of both ventricles.

Potential causal factors of “heart-shaped cladode” malformations in cactus pear (Opuntia ficus-indica (L.) Miller)

The prevalence and severity of pests and diseases are factors that limit productivity and quality in commercial cactus pear plantations in Mexico. Recently, in several cactus pear producing regions the appearance of diverse symptoms associated with “heart-shaped cladodes” has been registered. This disease is characterized by the loss of apical dominance of vegetative shoots leading to abnormal cladode growth. Besides the aesthetic damage, vegetative and floral buds disappear in the zone of invagination, thus reducing productivity. Because to date the causal agent is unknown, this study was conducted to analyze three possible agents, damage by insects, physical damage and phytoplasmas that could possibly cause the symptomatology of “heart-shaped cladode”, aiming to constitute a base line for future studies. The study was conducted under semi-controlled conditions and in the field, using Opuntia ficus-indica cv. Villanueva plants and cladodes. To rule out causal agents that occur naturally in cactus pear productive systems, the following characteristics were analyzed: detected presence of Diabrotica undecimpunctata, simulation of physical damage by puncturing 4- and 13-day-old shoots with a needle, and detection of phytoplasmas with PCR and RFLP. The results of the study showed that, although it feeds on shoots, D. undecimpunctata does not cause the symptoms. The puncture with a needle on the apical part promoted the presence of symptoms. The PCR and RFLP analyses detected the presence of phytoplasmas on both symptomatic and asymptomatic shoots. For this reason, it was not possible to conclude that phytoplasmas are the causal agents of heart-shaped cladode.

The microbiota characterizing huge carbonatic moonmilk structures and its correlation with preserved organic matter

BackgroundMoonmilk represents complex secondary structures and model systems to investigate the interaction between microorganisms and carbonatic rocks. Grotta Nera is characterized by numerous moonmilk speleothems of exceptional size hanging from the ceiling, reaching over two meters in length. In this work we combined microbiological analyses with analytical pyrolysis and carbon stable isotope data to determine the molecular composition of these complex moonmilk structures as well as the composition of the associated microbiota.ResultsThree moonmilk structures were dissected into the apical, lateral, and core parts, which shared similar values of microbial abundance, richness, and carbon isotopes but different water content, microbiota composition, and organic matter. Moonmilk parts/niches showed higher values of microbial biomass and biodiversity compared to the bedrock (not showing moonmilk development signs) and the waters (collected below dripping moonmilk), indicating the presence of more complex microbial communities linked to carbonate rock interactions and biomineralization processes. Although each moonmilk niche was characterized by a specific microbiota as well as a distinct organic carbon profile, statistical analyses clustered the samples in two main groups, one including the moonmilk lateral part and the bedrock and the other including the core and apical parts of the speleothem. The organic matter profile of both these groups showed two well-differentiated organic carbon groups, one from cave microbial activity and the other from the leaching of vascular plant litter above the cave. Correlation between organic matter composition and microbial taxa in the different moonmilk niches were found, linking the presence of condensed organic compounds in the apical part with the orders Nitrospirales and Nitrosopumilales, while different taxa were correlated with aromatic, lignin, and polysaccharides in the moonmilk core. These findings are in line with the metabolic potential of these microbial taxa suggesting how the molecular composition of the preserved organic matter drives the microbiota colonizing the different moonmilk niches. Furthermore, distinct bacterial and archaeal taxa known to be involved in the metabolism of inorganic nitrogen and C1 gases (CO2 and CH4) (Nitrospira, Nitrosopumilaceae, Nitrosomonadaceae, Nitrosococcaceae, and novel taxa of Methylomirabilota and Methanomassiliicoccales) were enriched in the core and apical parts of the moonmilk, probably in association with their contribution to biogeochemical cycles in Grotta Nera ecosystem and moonmilk development.ConclusionsThe moonmilk deposits can be divided into diverse niches following oxygen and water gradients, which are characterized by specific microbial taxa and organic matter composition originating from microbial activities or deriving from soil and vegetation above the cave. The metabolic capacities allowing the biodegradation of complex polymers from the vegetation above the cave and the use of inorganic nitrogen and atmospheric gases might have fueled the development of complex microbial communities that, by interacting with the carbonatic rock, led to the formation of these massive moonmilk speleothems in Grotta Nera.

Micro-computed tomographic evaluation on the quality of single-cone obturation using a modified passive-deflation sealer injection needle: an in vitro study.

This study aimed to design a modified passive-deflation sealer injection needle and investigate its ability to improve obturation quality of single-cone technique through assessing the distribution of voids in root canals using micro-computed tomography (micro-CT). Forty-eight mandibular incisors were divided into eight groups (n = 6), according to the taper of root canal preparation (0.06 or 0.04), the needle used for sealer injection (modified or commercial iRoot SP injection needle), and the obturation method (iRoot SP sealer-only or single-cone obturation). After obturation, each specimen was scanned by micro-CT. The volumetric percentage and distribution of all voids were first analyzed and compared among groups, then the open and closed voids were separately analyzed and compared among single-cone obturation groups. Compared to commercial needle groups, modified needle groups showed much less voids, especially in the apical root canal part (P < 0.05). Besides, the modified needle groups produced much less open voids than commercial needle groups despite the root canal taper (P < 0.05). The modified passive deflation sealer injection needle could effectively improve the quality of single-cone obturation through reducing intra-canal voids, especially open voids throughout the root canal, thus might possibly be developed as an effective intra-canal sealer delivering instrument.

Successful repair of recurrent ventricular septal perforation after myocardial infarction using double patch technique via right ventriculotomy: a case report

BackgroundPost-myocardial infarction (MI) ventricular septal perforation (VSP) is a rare but life-threatening complication. Surgical repair is challenging and carries significant risks, particularly in the context of recurrent VSPs. This case study presents a patient with recurrent VSP after initial surgical repair following myocardial infarction.Case presentationA 65-year-old male were re-administered to our hospital due to recurrent VSP. He was during follow up after undergone emergency VSP closure surgery 2 months earlier, utilizing the bovine double patch technique via left ventriculostomy. The initial VSP was located in the apical part of the interventricular septum, while the recurrent VSP appeared in the upper middle portion of the interventricular septum (Fig. 1). As the previous patch remained intact, the second surgery employed the bovine double patch technique via right ventriculostomy. The patient’s condition remained stable without the development of heart failure symptoms.ConclusionRepairing recurrent VSPs remains a challenge, necessitating the mastery of appropriate approaches to achieve optimal outcomes. Further research and guidelines are required to refine management strategies for recurrent VSPs.

Apical root canal microbiome associated with primary and posttreatment apical periodontitis: A systematic review.

Microorganisms colonizing the apical root canal system are conceivably the ones directly involved with the causation and maintenance of apical periodontitis. This article systematically reviews the reports on the microbiome occurring exclusively at the apical root canal of teeth with primary and posttreatment apical periodontitis. The electronic databases PubMed, Embase, Web of Science, Science Direct, and Proquest were searched up to August 2023. Clinical studies using culture and molecular microbiology methods to identify the microbial taxa present exclusively in the apical root canal segment of infected teeth with apical periodontitis were included. Studies were critically assessed using the Joanna Briggs Institute Critical Prevalence Assessment Checklist. From 2277 articles initially detected, 52 were selected for full reading and 21 were eventually included in this review. Of these, molecular methods were used in 19 and culture in 2 studies. Ten studies evaluated primary infections, 8 evaluated posttreatment infections, and 3 included both. Cryopulverization of the apical root specimens was conducted in 11 studies. All studies evaluated the prevalence and diversity of bacteria, and only one also reported on fungi. Overall, the most frequent/abundant bacterial taxa found in the apical canal of primary infections were Pseudoramibacter alactolyticus, Olsenella uli, Fusobacterium species, Streptococcus species, Porphyromonas endodontalis, Prevotella species, Actinomyces species, Parvimonas micra, Treponema denticola, Synergistetes species, and an as-yet uncharacterized taxon. In posttreatment infections, the most prevalent/abundant bacterial taxa included species of Streptococcus, Enterococcus, Fusobacterium, Actinomyces, Pseudoramibacter, Pseudomonas, and Propionibacterium. At the phylum level, Firmicutes was the most represented. The average apical bacterial load ranged from 105 to 106 in primary infections and from 103 to 104 in posttreatment infections. Microbial diversity in the apical part of the root canal system was examined encompassing data from both primary and posttreatment infections. Heterogeneity amongst the studies, especially in sample collection and microbial identification methods, is an important limitation that prevented a meta-analysis. There is a pronounced bacterial diversity in the infected apical canal, with a high interindividual variability. Different microbiome compositions at the species/genus level are observed according to the infection type. PROSPERO CRD42021275886.

Composition and Functional Properties of the Edible Spear and By-Products from Asparagus officinalis L. and Their Potential Prebiotic Effect.

Asparagus is a healthy food appreciated for its organoleptic characteristics, nutritional composition and physiological properties. During its industrial processing, a large amount of by-products are generated, since only the apical part of the vegetable is considered edible and a large amount of by-products are generated that could be of nutritional interest. Therefore, the nutritional composition of the edible part and the two by-products of the plant (root and stem) was evaluated, including dietary fiber, inulin, low-molecular-weight carbohydrates, low-molecular-weight polyphenols and macromolecular polyphenols. The hydration properties, oil retention capacity, glucose retardation index and impact on bacterial growth of both probiotic bacteria and pathogenic strains were determined. All samples were high in fiber (>22 g/100 g dw), fructans (>1.5 g/100 g dw) and polyphenolic compounds (>3 g/100 g dw) and had good water-, oil- and glucose-binding capacity. In addition, they promoted the growth of probiotic strains but not pathogenic ones. The effects were more pronounced in the spear by-product samples and appear to be related to the components of dietary fiber. The results indicate that edible spear has potential beneficial effects on host health and microbiota when ingested as part of a healthy diet, while the by-products could be used as supplements and/or as natural ingredients in fiber-enriched foods that require emulsification and are intended to achieve a prebiotic effect.

Transcriptome exploration of ferroptosis-related genes in TGFβ- induced lens epithelial to mesenchymal transition during posterior capsular opacification development

BackgroundPosterior capsular opacification (PCO) is the main reason affecting the long-term postoperative result of cataract patient, and it is well accepted that fibrotic PCO is driven by transforming growth factor beta (TGFβ) signaling. Ferroptosis, closely related to various ocular diseases, but has not been explored in PCO.MethodsRNA sequencing (RNA-seq) was performed on both TGF-β2 treated and untreated primary lens epithelial cells (pLECs). Differentially expressed genes (DEGs) associated with ferroptosis were analyzed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) to investigate their biological function. Additionally, protein-to-protein interactions among selected ferroptosis-related genes by PPI network and the top 10 genes with the highest score (MCC algorithm) were selected as the hub genes. The top 20 genes with significant fold change values were validated using quantitative real-time polymerase chain reaction (qRT-PCR).ResultsOur analysis revealed 1253 DEGs between TGF-β2 treated and untreated pLECs, uncovering 38 ferroptosis-related genes between two groups. Among these 38 ferroptosis-related genes,the most prominent GO enrichment analysis process involved in the response to oxidative stress (BPs), apical part of cell (CCs),antioxidant activity (MFs). KEGG were mainly concentrated in fluid shear stress and atherosclerosis, IL-17 and TNF signaling pathways, and validation of top 20 genes with significant fold change value were consistent with RNA-seq.ConclusionsOur RNA-Seq data identified 38 ferroptosis-related genes in TGF-β2 treated and untreated pLECs, which is the first observation of ferroptosis related genes in primary human lens epithelial cells under TGF-β2 stimulation.Graphical Our study initially observed ferroptosis related genes in primary human lens epithelial cells stimulated by TGF-β2. These findings may improve the understanding of the molecular mechanisms of PCO and provide a new direction for exploring the potential mechanisms of PCO

Efficiency of Canal Brush and Ultrasonic Activated Irrigation in Smear Layer Removal Using Two Different Chelating Agents (In Vitro Study)

Objective: This study aims to evaluate the efficiency of two different activation methods after using two different chelating agents inthe removal of the smear layer.&#x0D; Methods: In this study, seventy single-rooted mandibular premolar teeth were included, and divided into six study groups and onecontrol group according to the chelating agents and activation methods used. In groups 1,3, and 5, EDTA was used as the chelatingagent, where it was activated by Canal Brush in G3 and by Ultra Smart in G5. In groups 2,4, and 6, 7% Maleic acid was used insteadand activated by Canal Brush in G4 and Ultra Smart in G6. While in G1 and G2, no activation systems were used. The 7th group wasa negative control and purposed to verify the internal microstructure, so only distal water was irrigated (no activation and no chelatingagent was used). Samples were sectioned longitudinally and prepared for Scanning Electron Microscope (SEM) analysis in the coronal,middle, and apical parts. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests. The level of significancewas set to 0.05 (P &lt; 0.05).&#x0D; Results: Although the G5 (Ultra Smart +EDTA) median score showed the best smear layer removal score, it was not statisticallysignificant in comparison with the other 5 study groups. In all groups (whether Maleic acid or EDTA were used), smear layer removalwas effective in the coronal and middle thirds while less effective in the apical third, with no statistically significant difference betweenthe chelating agents.&#x0D; Conclusions: Under the limitations of this in vitro study, no activation system was able to remove the smear layer from the root canalwall completely. However, NaOCl and EDTA's irrigation sequence combined with Ultra Smart (ultrasonic activation) obtained betterresults than the other techniques.

Evaluation of Obturating Material Removal from Root Canal by Hedstrom and Rotary Retreatment File

An in vitro investigation was conducted to assess the efficacy of Hedstrom and Rotary Retreatment File using Cone Beam Computed Tomography (CBCT) in removing obturating material from moderately to severely curved root canals. Thirty-six removed human molar teeth were split into two groups based on the canal curvature using the Schafer and Schneider method. Each group consisted of 18 teeth. Teeth in Group A had roots that were moderately curved (angles between 10 and 20 degrees), whereas teeth in Group B had roots that were severely curved (angles more than 20 degrees). Following decoronation, each root was ready for obturation using the appropriate rotary files, following the manufacturer’s recommendations. Using the CBCT image, the total surface area of the root canals in the axial cross-section and the volume analysis of the obturated area were calculated. H files were used to retreat half of each group, while Rotary (ProTaper) retreatment files were used for the other half, in accordance with their retreatment protocol. It was noted how long it took to reach the working length and remove all obturating items. Cone beam computed tomography and Auto CAD software are used to analyze the surface area and volume of any residual obturating material in the canal after it has been completely removed. An analysis of the data using the ANOVA test was conducted between four groups. When p &lt; 0.05 was reached, it was deemed statistically significant. Rotary retreatment files were discovered to be the most efficient method for removing obturating material and to take the least amount of time to achieve working length. Compared to the Rotary retreatment file, the H file left greater residue in the root canal. Compared to moderately curved root canal groups, severely curved root canal groups have noticeably more residues. In all four groups, the apical part had more residues than the middle and coronal portions. The obturating substance in the root canal could not be entirely removed using any of the retreatment procedures. Furthermore, there was no advantage in terms of root-filling removal’s effectiveness.

MORPHOLOGICAL CHANGES OF RAT PERIODONTIUM IN SUPRAOCCLUSAL RELATIONS OF INDIVIDUAL TEETH IN THE AGE ASPECT

Although the issue of the occlusal load influence on the occurrence of pathological phenomena in the body has been discussed for decades, it is still a subject of debate. Pathogenic occlusion is defined as excessive occlusal forces (premature contacts and interference) that can cause injuries to the dentition, including teeth and periodontal tissues. Changes in occlusal dimensions, if not properly performed or treated, can lead to dysfunctions of the dentition, such as joint clicking, difficulty in chewing, occlusal discomfort, muscle fatigue, and pain.&#x0D; Aim: to determine the morphological changes of periodontium in rats of different age groups in the supraocclusal relationship of individual teeth in the age aspect.&#x0D; Materials and methods of the study. The study was conducted on 60 white laboratory rats aged 4 to 22 months and weighing 90 to 330 g. The rats were divided into control (30 animals) and experimental (30 animals) groups. Each group was divided into 3 subgroups (10 animals each) depending on the age of the rats: young, mature and senile. Young animals included rats aged 3 4 months with a weight of 90 100 g; mature animals aged 6-8 months with a weight of 150 170 g; senile rats 20 22 months and weighing 200 220 g. In the experimental group, the state of supraocclusion was modeled by increasing the height of the lower right second molars by placing 1 mm high filling. For the placement of the filling, 37% orthophosphorus etching gel for enamel and dentin (Latus, Ukraine), microapplicators (Latus, Ukraine), the fifth generation Prime&amp;Bond NT adhesive system (Dentsply Sirona, Germany), the universal microhybrid light-curing composite material Latelux (Latus, Ukraine) and the photopolymerizer LED.D (WOODPECKER, China) were used according to the manufacturer's instructions. The experimental animals were withdrawn from the experiment on the 15th day by decapitation under general anesthesia with sodium thiopental. The lower jaws were skeletonized, and dental blocks were cut out in the area of the molars. For histological examination, the dental blocks were fixed in a 10% solution of neutral formalin for two days, dehydrated in alcohols of increasing concentration and embedded in paraffin. Then, sections were made from the obtained preparations on a Shandon Finesse 325 rotary microtome with a section thickness of 4-6 μm. The histological sections were fixed on degreased slides and dried. Van Gieson staining was performed. The width of the periodontal gap was determined using the ZEISS ZEN 3.7 program by Carl Zeiss Microscopy.&#x0D; Results of the study. Histometric analysis has showed significant morphological changes in the experimental group of all age categories. In young rats, the fibrinoid edema phenomena of the periodontal ligament collagen fibers were observed. In mature rats, there was a picture of mucoid edema of collagen fibers of the periodontal ligament. In senile rats, fibrinoid necrosis of collagen fibers of the periodontal ligament were discovered, an inflammatory infiltrate, macrophages and neutrophils, with a predominance of neutrophilic inflammatory microenvironment, and initial hyaline tissue changes were found. In all age groups, there was cement resorption on the lateral surfaces of the tooth root, lacunar resorption of alveolar bone tissue and the presence of a large number of osteoclasts. In senile rats, hypercementosis was determined in the apical part of the root. In the control group of all age categories, neither resorption nor disorganization of connective tissue, nor hypercementosis was detected.&#x0D; Conclusions. The study shows that traumatic occlusion leads to resorption of root and alveolar cementum in all age groups. In young rats, traumatic occlusion causes fibrinoid edema of collagen fibers of the periodontal ligament. In mature rats, traumatic occlusion causes mucoid edema of collagen fibers of the periodontal ligament. In senile rats, traumatic occlusion causes fibrinoid necrosis of collagen fibers of the periodontal ligament, initial hyaline tissue changes and hypercementosis.

Effect of sodium hypochlorite and calcium hypochlorite on the apical sealing ability of endodontic sealers

Aim: This study aimed to compare the influence of sodium hypochlorite (NaOCl) and calcium hypochlorite [Ca(OCl)2 ] on the apical sealing capacity of AH Plus (Dentsply Maillefer) and Bio-C Sealer (Angelus) endodontic sealers. Methods: Sixty permanent human lower incisors were randomly allocated (http://www.randomized.org), according to the irrigant used, into three groups (n=20): 0.9% sodium chloride (NaCl/Control); 2.5% NaOCl; and 2.5% Ca(OCl)2 . The root canal was prepared with rotary files under 10 mL of the solution corresponding to the experimental group. Each group was subdivided into two (n=10) according to the sealer used for filling: AH Plus (Dentsply Maillefer) or Bio-C Sealer (Angelus). Then, all samples were immersed in black India ink for one week. After the storage period, the roots were then grooved longitudinally and split, and the ink penetration was measured from the apical part to the coronal part of the root canal into which the ink penetrated using a stereomicroscope. Data were analyzed by one-way ANOVA and Tukey’s post-hoc tests. Results: There was no statistical difference in ink penetration between the different endodontic sealers tested for the same irrigating solution (p &gt; 0.05). However, when the Bio-C Sealer (Angelus) was used, the group treated with 2.5% Ca(OCl)2 was associated with lower values of apical leakage, compared to 2.5% NaOCl (p &lt; 0.05). For the AH Plus sealer (Dentsply Maillefer), there was no difference between the irrigants (p &gt; 0.05). Conclusions: Associating Ca(OCl)2 irrigant with Bio-C Sealer (Angelus) seems to be a good option to reduce apical leakage.

Identification of Hub Genes and Potential Pathogenesis in Gastric Cancer Based on Integrated Gene Expression Profile Analysis.

Gastric cancer (GC) is one of the most common malignancies and ranks third in terms of cancer-related mortality. This study aims to identify the hub genes and potential mechanisms in GC using a bioinformatics approach. Microarray data GSE54129, GSE79973, GSE55696 were extracted from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) was identified using Benjamini-Hochberg method in the limma package. GO and KEGG pathway enrichment analyses of the DEGs were conducted. Furthermore, protein-protein interaction network was constructed the STRING platform, and the hub genes were discovered using Maximal Clique Centrality method via cytoHubba. The predictive significance of hub genes was evaluated through GSE15459 dataset. A total of 73 genes was identified as DEGs in GC. Volcano plots and heatmaps of DEGs were visualized. Functional enrichment analysis revealed that the genes were mostly enriched in response to xenobiotic stimulus, digestion, cellular hormone metabolic process, extracellular matrix structural constituent, calcium-dependent cysteine-type endopeptidase activity, aromatase activity, apical part of cell, basal part of cell, and apical plasma membrane. Regarding KEGG pathway-enrichment, the genes were mainly involved in Drug metabolism-cytochrome P450, Retinol metabolism, Chemical carcinogenesis-DNA adducts, Gastric acid secretion, and Metabolism of xenobiotics by cytochrome P450. By combining the results of Cytohubba, the top five intersecting genes identified were SPP1, INHBA, MMP7, THBS2 and FAP. Kapplan-Meier analysis results showed that these 5 hub genes were highly related to the overall survival of patients. SPP1, INHBA, MMP7, THBS2, and FAP were identified as prospective biomarkers and therapeutic targets for GC that might be utilized for prognostic evaluation and scheme selection.

Effect on Endoplasmic Reticulum Stress of the Combined Oral Contraceptives in the Kidney

Objective: This study aimed to analyze the effects of combined oral contraceptive active ingredients, Drospirenone, Ethinyl Estradiol, and Ethinyl Estradiol+Drospirenone, on liver histopathological changes and endoplasmic reticulum stress levels. Material and Methods: In the study, 37 Balb/c female mice were used. Mice were randomly divided into the Control, Sham, Drospirenone, Ethinyl Estradiol, and Ethinyl Estradiol+Drospirenone groups. The experimental groups were administered with gavage to 8-week-old female mice for 35 days. Kidney tissue sections were applied with Hematoxylin&amp;Eosin, Orcein, Mallory’s Azan, and Periodic Acid-Schiff to detect histopathological changes, and Chop and Grp78 were used to detect Endoplasm Reticulum Stress. Results: Significant loss of microvilli and a decrease in glycogen accumulation were observed in the apical part of some of the proximal tubules of animals in the Drospirenone and Ethinyl Estradiol+Drospirenone groups. The amount of collagen fiber stained with Mallory’s Azan increased in the parietal layer of Bowman’s capsule of the kidney tissues of the Drospirenone and Ethinyl Estradiol+Drospirenone applied groups, but no difference was observed in elastic fibers in all groups. The expression level of Grp78 and Chop proteins in the kidney tubules of female mice given Drospirenone, Ethinyl Estradiol, and Ethinyl Estradiol+Drospirenone was significantly higher compared to the control group. Conclusion: In this study, it was shown that the expression of Grp78 and Chop markers detected in the mouse kidney increased as a result of Drospirenone, Ethinyl Estradiol and Ethinyl Estradiol + Drospirenone administration, thus causing kidney cell apoptosis by inducing ER-dependent death pathway activity.

What controls Sn-W mineralization in granite batholith: A case study from the world-class Dulong Sn-Zn polymetallic ore deposit of SW China

Magmatic-hydrothermal ore deposits hosted in granitic batholiths are an important source of tungsten (W) and tin (Sn). However, it remains enigmatic whether and how the Sn-W mineralization is triggered by the spatially associated batholith because the Sn-W-bearing granitic rocks are more likely to occur as small intrusions. Here we used a combination of LA-ICP-MS cassiterite U-Pb dates, published whole-rock geochemical, and high-precision exploration data to evaluate a genetic link between the world-class Dulong Sn-Zn polymetallic ore deposit and its spatially associated batholith in SW China. Our new cassiterite U-Pb dates indicate that the Sn-Zn and Sn-Cu mineralization events were temporally associated with the emplacement of concealed granites and porphyritic dykes respectively, consistent with the spatial pattern between Sn-Zn-Cu mineralized zones and granitic rocks in the Dulong ore district as revealed by the high-precision exploration data. The compiled data presented in this study show that these granitic rocks throughout the batholith are of S-type and highly fractionated affinities, and their parent magmas might experience similar degrees of fractionation. Importantly, the low Nb/Ta ratios (most < ∼5) in granites of the Dulong ore district are markedly differentiated from highly variable values (∼2.0 to ∼ 9.4) in the batholith, which may be caused by the extensive sub-solidus interaction with late magmatic fluids. Furthermore, the granites of the Dulong ore district are significantly poorer in Sn-Zn contents than those of the Laojunshan batholith, suggesting the extensive Sn-Zn-rich fluids exsolved from highly evolved granitic magmas could lead to a significant decrease in Sn-Zn contents in consolidated granites and the formation of Sn-Zn ore deposit, due to the relatively high fluid/melt partition coefficients of Sn and Zn. In conjunction with evidence from previous numerical and mineralogical models, and the spatial pattern between Sn-Zn mineralized zones and apical parts of concealed pluton in the Dulong ore district as revealed by high-precision drill data, we propose a model involving highly evolved granitic magmas that formed batholith, apical portions of which as the emanative centers of Sn-Zn-rich fluids played a crucial role in the formation of the world-class ore deposit.